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1 11 aaronmk
# Database access
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import copy
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import operator
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import re
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import warnings
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import exc
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import dicts
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import iters
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import lists
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from Proxy import Proxy
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import rand
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import sql_gen
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import strings
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import util
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##### Exceptions
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def get_cur_query(cur, input_query=None, input_params=None):
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    raw_query = None
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    if hasattr(cur, 'query'): raw_query = cur.query
23
    elif hasattr(cur, '_last_executed'): raw_query = cur._last_executed
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25
    if raw_query != None: return raw_query
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    else: return '[input] '+strings.ustr(input_query)+' % '+repr(input_params)
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def _add_cursor_info(e, *args, **kw_args):
29
    '''For params, see get_cur_query()'''
30
    exc.add_msg(e, 'query: '+str(get_cur_query(*args, **kw_args)))
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class DbException(exc.ExceptionWithCause):
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    def __init__(self, msg, cause=None, cur=None):
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        exc.ExceptionWithCause.__init__(self, msg, cause, cause_newline=True)
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        if cur != None: _add_cursor_info(self, cur)
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class ExceptionWithName(DbException):
38
    def __init__(self, name, cause=None):
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        DbException.__init__(self, 'for name: '+str(name), cause)
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        self.name = name
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class ExceptionWithNameValue(DbException):
43
    def __init__(self, name, value, cause=None):
44
        DbException.__init__(self,
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            'for name: '+str(name)+'; value: '+repr(value), cause)
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        self.name = name
47
        self.value = value
48
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class ConstraintException(DbException):
50
    def __init__(self, name, cols, cause=None):
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        DbException.__init__(self, 'Violated '+name+ ' constraint on columns: '
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            +(', '.join(cols)), cause)
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        self.name = name
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        self.cols = cols
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class NameException(DbException): pass
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class DuplicateKeyException(ConstraintException): pass
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class NullValueException(ConstraintException): pass
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class FunctionValueException(ExceptionWithNameValue): pass
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class DuplicateTableException(ExceptionWithName): pass
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class DuplicateFunctionException(ExceptionWithName): pass
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class EmptyRowException(DbException): pass
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##### Warnings
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class DbWarning(UserWarning): pass
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##### Result retrieval
75
76
def col_names(cur): return (col[0] for col in cur.description)
77
78
def rows(cur): return iter(lambda: cur.fetchone(), None)
79
80
def consume_rows(cur):
81
    '''Used to fetch all rows so result will be cached'''
82
    iters.consume_iter(rows(cur))
83
84
def next_row(cur): return rows(cur).next()
85
86
def row(cur):
87
    row_ = next_row(cur)
88
    consume_rows(cur)
89
    return row_
90
91
def next_value(cur): return next_row(cur)[0]
92
93
def value(cur): return row(cur)[0]
94
95
def values(cur): return iters.func_iter(lambda: next_value(cur))
96
97
def value_or_none(cur):
98
    try: return value(cur)
99
    except StopIteration: return None
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##### Input validation
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def check_name(name):
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    if re.search(r'\W', name) != None: raise NameException('Name "'+name
105
        +'" may contain only alphanumeric characters and _')
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def esc_name_by_module(module, name, ignore_case=False):
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    if module == 'psycopg2' or module == None:
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        if ignore_case:
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            # Don't enclose in quotes because this disables case-insensitivity
111
            check_name(name)
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            return name
113
        else: quote = '"'
114
    elif module == 'MySQLdb': quote = '`'
115
    else: raise NotImplementedError("Can't escape name for "+module+' database')
116
    return quote + name.replace(quote, '') + quote
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118
def esc_name_by_engine(engine, name, **kw_args):
119
    return esc_name_by_module(db_engines[engine][0], name, **kw_args)
120
121
def esc_name(db, name, **kw_args):
122
    return esc_name_by_module(util.root_module(db.db), name, **kw_args)
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def qual_name(db, schema, table):
125
    def esc_name_(name): return esc_name(db, name)
126
    table = esc_name_(table)
127
    if schema != None: return esc_name_(schema)+'.'+table
128
    else: return table
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##### Database connections
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db_config_names = ['engine', 'host', 'user', 'password', 'database', 'schemas']
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db_engines = {
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    'MySQL': ('MySQLdb', {'password': 'passwd', 'database': 'db'}),
136
    'PostgreSQL': ('psycopg2', {}),
137
}
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DatabaseErrors_set = set([DbException])
140
DatabaseErrors = tuple(DatabaseErrors_set)
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def _add_module(module):
143
    DatabaseErrors_set.add(module.DatabaseError)
144
    global DatabaseErrors
145
    DatabaseErrors = tuple(DatabaseErrors_set)
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def db_config_str(db_config):
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    return db_config['engine']+' database '+db_config['database']
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def _query_lookup(query, params): return (query, dicts.make_hashable(params))
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log_debug_none = lambda msg: None
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class DbConn:
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    def __init__(self, db_config, serializable=True, autocommit=False,
156
        caching=True, log_debug=log_debug_none):
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        self.db_config = db_config
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        self.serializable = serializable
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        self.autocommit = autocommit
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        self.caching = caching
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        self.log_debug = log_debug
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        self.debug = log_debug != log_debug_none
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        self.__db = None
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        self.query_results = {}
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        self._savepoint = 0
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    def __getattr__(self, name):
169
        if name == '__dict__': raise Exception('getting __dict__')
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        if name == 'db': return self._db()
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        else: raise AttributeError()
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    def __getstate__(self):
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        state = copy.copy(self.__dict__) # shallow copy
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        state['log_debug'] = None # don't pickle the debug callback
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        state['_DbConn__db'] = None # don't pickle the connection
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        return state
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    def connected(self): return self.__db != None
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    def _db(self):
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        if self.__db == None:
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            # Process db_config
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            db_config = self.db_config.copy() # don't modify input!
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            schemas = db_config.pop('schemas', None)
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            module_name, mappings = db_engines[db_config.pop('engine')]
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            module = __import__(module_name)
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            _add_module(module)
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            for orig, new in mappings.iteritems():
190
                try: util.rename_key(db_config, orig, new)
191
                except KeyError: pass
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            # Connect
194
            self.__db = module.connect(**db_config)
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            # Configure connection
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            if self.serializable and not self.autocommit: run_raw_query(self,
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                'SET TRANSACTION ISOLATION LEVEL SERIALIZABLE')
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            if schemas != None:
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                schemas_ = ''.join((esc_name(self, s)+', '
201
                    for s in schemas.split(',')))
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                run_raw_query(self, "SELECT set_config('search_path', \
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%s || current_setting('search_path'), false)", [schemas_])
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        return self.__db
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    class DbCursor(Proxy):
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        def __init__(self, outer):
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            Proxy.__init__(self, outer.db.cursor())
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            self.outer = outer
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            self.query_results = outer.query_results
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            self.query_lookup = None
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            self.result = []
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        def execute(self, query, params=None):
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            self._is_insert = query.upper().find('INSERT') >= 0
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            self.query_lookup = _query_lookup(query, params)
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            try:
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                try:
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                    return_value = self.inner.execute(query, params)
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                    self.outer.do_autocommit()
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                finally: self.query = get_cur_query(self.inner)
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            except Exception, e:
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                _add_cursor_info(e, self, query, params)
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                self.result = e # cache the exception as the result
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                self._cache_result()
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                raise
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            # Fetch all rows so result will be cached
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            if self.rowcount == 0 and not self._is_insert: consume_rows(self)
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            return return_value
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        def fetchone(self):
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            row = self.inner.fetchone()
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            if row != None: self.result.append(row)
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            # otherwise, fetched all rows
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            else: self._cache_result()
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            return row
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        def _cache_result(self):
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            # For inserts, only cache exceptions since inserts are not
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            # idempotent, but an invalid insert will always be invalid
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            if self.query_results != None and (not self._is_insert
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                or isinstance(self.result, Exception)):
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                assert self.query_lookup != None
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                self.query_results[self.query_lookup] = self.CacheCursor(
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                    util.dict_subset(dicts.AttrsDictView(self),
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                    ['query', 'result', 'rowcount', 'description']))
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        class CacheCursor:
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            def __init__(self, cached_result): self.__dict__ = cached_result
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            def execute(self, *args, **kw_args):
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                if isinstance(self.result, Exception): raise self.result
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                # otherwise, result is a rows list
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                self.iter = iter(self.result)
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            def fetchone(self):
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                try: return self.iter.next()
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                except StopIteration: return None
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    def esc_value(self, value):
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        module = util.root_module(self.db)
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        if module == 'psycopg2': str_ = self.db.cursor().mogrify('%s', [value])
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        elif module == 'MySQLdb':
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            import _mysql
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            str_ = _mysql.escape_string(value)
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        else: raise NotImplementedError("Can't escape value for "+module
269
            +' database')
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        return strings.to_unicode(str_)
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    def esc_name(self, name): return esc_name(self, name) # calls global func
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    def run_query(self, query, params=None, cacheable=False):
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        '''Translates known DB errors to typed exceptions:
276
        See self.DbCursor.execute().'''
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        assert query != None
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        if not self.caching: cacheable = False
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        used_cache = False
281
        try:
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            # Get cursor
283
            if cacheable:
284
                query_lookup = _query_lookup(query, params)
285
                try:
286
                    cur = self.query_results[query_lookup]
287
                    used_cache = True
288
                except KeyError: cur = self.DbCursor(self)
289
            else: cur = self.db.cursor()
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            # Run query
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            cur.execute(query, params)
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        finally:
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            if self.debug: # only compute msg if needed
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                if used_cache: cache_status = 'Cache hit'
296
                elif cacheable: cache_status = 'Cache miss'
297
                else: cache_status = 'Non-cacheable'
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                self.log_debug(cache_status+': '
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                    +strings.one_line(str(get_cur_query(cur, query, params))))
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301
        return cur
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303
    def is_cached(self, query, params=None):
304
        return _query_lookup(query, params) in self.query_results
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306
    def with_savepoint(self, func):
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        savepoint = 'level_'+str(self._savepoint)
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        self.run_query('SAVEPOINT '+savepoint)
309
        self._savepoint += 1
310
        try:
311
            try: return_val = func()
312
            finally:
313
                self._savepoint -= 1
314
                assert self._savepoint >= 0
315
        except:
316
            self.run_query('ROLLBACK TO SAVEPOINT '+savepoint)
317
            raise
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        else:
319
            self.run_query('RELEASE SAVEPOINT '+savepoint)
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            self.do_autocommit()
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            return return_val
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323
    def do_autocommit(self):
324
        '''Autocommits if outside savepoint'''
325
        assert self._savepoint >= 0
326
        if self.autocommit and self._savepoint == 0:
327
            self.log_debug('Autocommiting')
328
            self.db.commit()
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connect = DbConn
331
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##### Querying
333
334 1894 aaronmk
def run_raw_query(db, *args, **kw_args):
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    '''For params, see DbConn.run_query()'''
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    return db.run_query(*args, **kw_args)
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def mogrify(db, query, params):
339
    module = util.root_module(db.db)
340
    if module == 'psycopg2': return db.db.cursor().mogrify(query, params)
341
    else: raise NotImplementedError("Can't mogrify query for "+module+
342
        ' database')
343
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##### Recoverable querying
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def with_savepoint(db, func): return db.with_savepoint(func)
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def run_query(db, query, params=None, recover=None, cacheable=False):
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    if recover == None: recover = False
350
351 2148 aaronmk
    try:
352
        def run(): return run_raw_query(db, query, params, cacheable)
353
        if recover and not db.is_cached(query, params):
354
            return with_savepoint(db, run)
355
        else: return run() # don't need savepoint if cached
356
    except Exception, e:
357
        if not recover: raise # need savepoint to run index_cols()
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        msg = exc.str_(e)
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        match = re.search(r'duplicate key value violates unique constraint '
361 2368 aaronmk
            r'"((_?[^\W_]+)_[^"]+?)"', msg)
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        if match:
363
            constraint, table = match.groups()
364
            try: cols = index_cols(db, table, constraint)
365
            except NotImplementedError: raise e
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            else: raise DuplicateKeyException(constraint, cols, e)
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        match = re.search(r'null value in column "(\w+?)" violates not-null '
369 2239 aaronmk
            r'constraint', msg)
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        if match: raise NullValueException('NOT NULL', [match.group(1)], e)
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        match = re.search(r'\b(?:invalid input (?:syntax|value)\b.*?'
373
            r'|date/time field value out of range): "(.+?)"\n'
374 2368 aaronmk
            r'(?:(?s).*?)\bfunction "(\w+?)".*?\bat assignment', msg)
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        if match:
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            value, name = match.groups()
377
            raise FunctionValueException(name, strings.to_unicode(value), e)
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        match = re.search(r'relation "(\w+?)" already exists', msg)
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        if match: raise DuplicateTableException(match.group(1), e)
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        match = re.search(r'function "(\w+?)" already exists', msg)
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        if match: raise DuplicateFunctionException(match.group(1), e)
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        raise # no specific exception raised
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##### Basic queries
388
389 2153 aaronmk
def next_version(name):
390
    '''Prepends the version # so it won't be removed if the name is truncated'''
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    version = 1 # first existing name was version 0
392 2153 aaronmk
    match = re.match(r'^v(\d+)_(.*)$', name)
393
    if match:
394
        version = int(match.group(1))+1
395
        name = match.group(2)
396
    return 'v'+str(version)+'_'+name
397
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def run_query_into(db, query, params, into=None, *args, **kw_args):
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    '''Outputs a query to a temp table.
400
    For params, see run_query().
401
    '''
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    if into == None: return run_query(db, query, params, *args, **kw_args)
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    else: # place rows in temp table
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        assert isinstance(into, sql_gen.Table)
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        kw_args['recover'] = True
407
        while True:
408
            try:
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                create_query = 'CREATE'
410
                if not db.debug: create_query += ' TEMP'
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                create_query += ' TABLE '+into.to_str(db)+' AS '+query
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413
                return run_query(db, create_query, params, *args, **kw_args)
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                    # CREATE TABLE AS sets rowcount to # rows in query
415
            except DuplicateTableException, e:
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                into.name = next_version(into.name)
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                # try again with next version of name
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order_by_pkey = object() # tells mk_select() to order by the pkey
420
421 2199 aaronmk
distinct_on_all = object() # tells mk_select() to SELECT DISTINCT ON all columns
422
423 2233 aaronmk
def mk_select(db, tables, fields=None, conds=None, distinct_on=[], limit=None,
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    start=None, order_by=order_by_pkey, default_table=None):
425 1981 aaronmk
    '''
426 2121 aaronmk
    @param tables The single table to select from, or a list of tables to join
427 2280 aaronmk
        together, with tables after the first being sql_gen.Join objects
428 1981 aaronmk
    @param fields Use None to select all fields in the table
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    @param conds WHERE conditions: [(compare_left_side, compare_right_side),...]
430 2379 aaronmk
        * container can be any iterable type
431 2218 aaronmk
        * compare_left_side: Code|str (for col name)
432
        * compare_right_side: ValueCond|literal value
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    @param distinct_on The columns to SELECT DISTINCT ON, or distinct_on_all to
434
        use all columns
435 2054 aaronmk
    @return tuple(query, params)
436 1981 aaronmk
    '''
437 2315 aaronmk
    # Parse tables param
438 2121 aaronmk
    if not lists.is_seq(tables): tables = [tables]
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    tables = list(tables) # don't modify input! (list() copies input)
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    table0 = sql_gen.as_Table(tables.pop(0)) # first table is separate
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    # Parse other params
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    if conds == None: conds = []
444
    elif isinstance(conds, dict): conds = conds.items()
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    conds = list(conds) # don't modify input! (list() copies input)
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    assert limit == None or type(limit) == int
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    assert start == None or type(start) == int
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    if order_by is order_by_pkey:
449
        if distinct_on != []: order_by = None
450
        else: order_by = pkey(db, table0, recover=True)
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452 2315 aaronmk
    query = 'SELECT'
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454 2315 aaronmk
    def parse_col(col): return sql_gen.as_Col(col, default_table).to_str(db)
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    # DISTINCT ON columns
457 2233 aaronmk
    if distinct_on != []:
458 2200 aaronmk
        query += ' DISTINCT'
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        if distinct_on is not distinct_on_all:
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            query += ' ON ('+(', '.join(map(parse_col, distinct_on)))+')'
461
462
    # Columns
463
    query += ' '
464 1135 aaronmk
    if fields == None: query += '*'
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    else: query += ', '.join(map(parse_col, fields))
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467
    # Main table
468 2271 aaronmk
    query += ' FROM '+table0.to_str(db)
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    # Add joins
471 2271 aaronmk
    left_table = table0
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    for join_ in tables:
473
        table = join_.table
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475 2343 aaronmk
        # Parse special values
476
        if join_.type_ is sql_gen.filter_out: # filter no match
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            conds.append((sql_gen.Col(table_not_null_col(db, table), table),
478
                None))
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480 2277 aaronmk
        query += ' '+join_.to_str(db, left_table)
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482
        left_table = table
483
484 865 aaronmk
    missing = True
485 2376 aaronmk
    if conds != []:
486 2284 aaronmk
        query += ' WHERE '+(' AND '.join((sql_gen.as_ValueCond(r).to_str(db, l)
487 2376 aaronmk
            for l, r in conds)))
488 865 aaronmk
        missing = False
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    if order_by != None:
490 2285 aaronmk
        query += ' ORDER BY '+sql_gen.as_Col(order_by, table0).to_str(db)
491 865 aaronmk
    if limit != None: query += ' LIMIT '+str(limit); missing = False
492
    if start != None:
493
        if start != 0: query += ' OFFSET '+str(start)
494
        missing = False
495
    if missing: warnings.warn(DbWarning(
496
        'SELECT statement missing a WHERE, LIMIT, or OFFSET clause: '+query))
497
498 2315 aaronmk
    return (query, [])
499 11 aaronmk
500 2054 aaronmk
def select(db, *args, **kw_args):
501
    '''For params, see mk_select() and run_query()'''
502
    recover = kw_args.pop('recover', None)
503
    cacheable = kw_args.pop('cacheable', True)
504
505
    query, params = mk_select(db, *args, **kw_args)
506
    return run_query(db, query, params, recover, cacheable)
507
508 2066 aaronmk
def mk_insert_select(db, table, cols=None, select_query=None, params=None,
509 2292 aaronmk
    returning=None, embeddable=False):
510 1960 aaronmk
    '''
511
    @param returning str|None An inserted column (such as pkey) to return
512 2070 aaronmk
    @param embeddable Whether the query should be embeddable as a nested SELECT.
513 2073 aaronmk
        Warning: If you set this and cacheable=True when the query is run, the
514
        query will be fully cached, not just if it raises an exception.
515 1960 aaronmk
    '''
516 2328 aaronmk
    table = sql_gen.as_Table(table)
517 2318 aaronmk
    if cols == []: cols = None # no cols (all defaults) = unknown col names
518
    if cols != None: cols = [sql_gen.as_Col(v).to_str(db) for v in cols]
519 2063 aaronmk
    if select_query == None: select_query = 'DEFAULT VALUES'
520 2327 aaronmk
    if returning != None: returning = sql_gen.as_Col(returning, table)
521 2063 aaronmk
522
    # Build query
523 2328 aaronmk
    query = 'INSERT INTO '+table.to_str(db)
524 2318 aaronmk
    if cols != None: query += ' ('+', '.join(cols)+')'
525 2063 aaronmk
    query += ' '+select_query
526
527
    if returning != None:
528 2327 aaronmk
        returning_name = copy.copy(returning)
529
        returning_name.table = None
530
        returning_name = returning_name.to_str(db)
531
        query += ' RETURNING '+returning_name
532 2063 aaronmk
533 2070 aaronmk
    if embeddable:
534 2327 aaronmk
        assert returning != None
535
536 2070 aaronmk
        # Create function
537 2330 aaronmk
        function_name = '_'.join(['insert', table.name] + cols)
538 2327 aaronmk
        return_type = 'SETOF '+returning.to_str(db)+'%TYPE'
539 2189 aaronmk
        while True:
540
            try:
541 2327 aaronmk
                func_schema = None
542
                if not db.debug: func_schema = 'pg_temp'
543
                function = sql_gen.Table(function_name, func_schema).to_str(db)
544 2194 aaronmk
545 2189 aaronmk
                function_query = '''\
546
CREATE FUNCTION '''+function+'''() RETURNS '''+return_type+'''
547 2070 aaronmk
    LANGUAGE sql
548
    AS $$'''+mogrify(db, query, params)+''';$$;
549
'''
550 2189 aaronmk
                run_query(db, function_query, recover=True, cacheable=True)
551
                break # this version was successful
552
            except DuplicateFunctionException, e:
553
                function_name = next_version(function_name)
554
                # try again with next version of name
555 2070 aaronmk
556 2337 aaronmk
        # Return query that uses function
557
        func_table = sql_gen.NamedTable('f', sql_gen.CustomCode(function+'()'),
558
            [returning_name]) # AS clause requires function alias
559
        return mk_select(db, func_table, start=0, order_by=None)
560 2070 aaronmk
561 2066 aaronmk
    return (query, params)
562
563
def insert_select(db, *args, **kw_args):
564 2085 aaronmk
    '''For params, see mk_insert_select() and run_query_into()
565 2386 aaronmk
    @param into sql_gen.Table with suggested name of temp table to put RETURNING
566
        values in
567 2072 aaronmk
    '''
568 2386 aaronmk
    into = kw_args.pop('into', None)
569
    if into != None: kw_args['embeddable'] = True
570 2066 aaronmk
    recover = kw_args.pop('recover', None)
571
    cacheable = kw_args.pop('cacheable', True)
572
573
    query, params = mk_insert_select(db, *args, **kw_args)
574 2386 aaronmk
    return run_query_into(db, query, params, into, recover=recover,
575 2153 aaronmk
        cacheable=cacheable)
576 2063 aaronmk
577 2066 aaronmk
default = object() # tells insert() to use the default value for a column
578
579 2063 aaronmk
def insert(db, table, row, *args, **kw_args):
580 2085 aaronmk
    '''For params, see insert_select()'''
581 1960 aaronmk
    if lists.is_seq(row): cols = None
582
    else:
583
        cols = row.keys()
584
        row = row.values()
585
    row = list(row) # ensure that "!= []" works
586
587 1961 aaronmk
    # Check for special values
588
    labels = []
589
    values = []
590
    for value in row:
591 2254 aaronmk
        if value is default: labels.append('DEFAULT')
592 1961 aaronmk
        else:
593
            labels.append('%s')
594
            values.append(value)
595
596
    # Build query
597 2063 aaronmk
    if values != []: query = ' VALUES ('+(', '.join(labels))+')'
598
    else: query = None
599 1554 aaronmk
600 2064 aaronmk
    return insert_select(db, table, cols, query, values, *args, **kw_args)
601 11 aaronmk
602 135 aaronmk
def last_insert_id(db):
603 1849 aaronmk
    module = util.root_module(db.db)
604 135 aaronmk
    if module == 'psycopg2': return value(run_query(db, 'SELECT lastval()'))
605
    elif module == 'MySQLdb': return db.insert_id()
606
    else: return None
607 13 aaronmk
608 1968 aaronmk
def truncate(db, table, schema='public'):
609
    return run_query(db, 'TRUNCATE '+qual_name(db, schema, table)+' CASCADE')
610 832 aaronmk
611
##### Database structure queries
612
613 2339 aaronmk
def table_cols(db, table, recover=None):
614
    return list(col_names(select(db, table, limit=0, order_by=None,
615
        recover=recover)))
616
617 2394 aaronmk
def mk_flatten_mapping(db, into, cols, preserve=[], as_items=False):
618 2383 aaronmk
    '''Creates a mapping from original column names (which may have collisions)
619
    to names that will be distinct among the given tables.
620
    This is meant to be used for several tables that are being joined together.
621 2392 aaronmk
    @param into The table for the new columns
622 2394 aaronmk
    @param preserve [sql_gen.Col...] Columns not to rename. Note that these
623
        columns will be included in the mapping even if they are not in cols.
624
        The tables of the provided Col objects will be changed to into, so make
625
        copies of them if you want to keep the original tables.
626
    @param as_items Whether to return a list of dict items instead of a dict
627 2383 aaronmk
    @return dict(orig_col=new_col, ...)
628
        * orig_col: sql_gen.Col(orig_col_name, orig_table)
629 2392 aaronmk
        * new_col: sql_gen.Col(orig_col_name, into)
630
        * All mappings use the into table so its name can easily be
631 2383 aaronmk
          changed for all columns at once
632
    '''
633 2394 aaronmk
    items = []
634 2389 aaronmk
    for col in preserve:
635 2390 aaronmk
        orig_col = copy.copy(col)
636 2392 aaronmk
        col.table = into
637 2394 aaronmk
        items.append((orig_col, col))
638
    preserve = set(preserve)
639
    for col in cols:
640
        if col not in preserve: items.append((col, sql_gen.Col(str(col), into)))
641
642
    if not as_items: items = dict(items)
643
    return items
644 2383 aaronmk
645 2393 aaronmk
def flatten(db, into, joins, cols, limit=None, start=None, **kw_args):
646 2391 aaronmk
    '''For params, see mk_flatten_mapping()
647
    @return See return value of mk_flatten_mapping()
648
    '''
649 2394 aaronmk
    items = mk_flatten_mapping(db, into, cols, as_items=True, **kw_args)
650
    cols = [sql_gen.NamedCol(new.name, old) for old, new in items]
651 2391 aaronmk
    run_query_into(db, *mk_select(db, joins, cols, limit=limit, start=start),
652 2392 aaronmk
        into=into)
653 2394 aaronmk
    return dict(items)
654 2391 aaronmk
655 2291 aaronmk
def pkey(db, table, recover=None):
656 832 aaronmk
    '''Assumed to be first column in table'''
657 2339 aaronmk
    return table_cols(db, table, recover)[0]
658 832 aaronmk
659 2340 aaronmk
not_null_col = 'not_null'
660
661
def table_not_null_col(db, table, recover=None):
662
    '''Name assumed to be the value of not_null_col. If not found, uses pkey.'''
663
    if not_null_col in table_cols(db, table, recover): return not_null_col
664
    else: return pkey(db, table, recover)
665
666 853 aaronmk
def index_cols(db, table, index):
667
    '''Can also use this for UNIQUE constraints, because a UNIQUE index is
668
    automatically created. When you don't know whether something is a UNIQUE
669
    constraint or a UNIQUE index, use this function.'''
670 1909 aaronmk
    module = util.root_module(db.db)
671
    if module == 'psycopg2':
672
        return list(values(run_query(db, '''\
673 853 aaronmk
SELECT attname
674 866 aaronmk
FROM
675
(
676
        SELECT attnum, attname
677
        FROM pg_index
678
        JOIN pg_class index ON index.oid = indexrelid
679
        JOIN pg_class table_ ON table_.oid = indrelid
680
        JOIN pg_attribute ON attrelid = indrelid AND attnum = ANY (indkey)
681
        WHERE
682
            table_.relname = %(table)s
683
            AND index.relname = %(index)s
684
    UNION
685
        SELECT attnum, attname
686
        FROM
687
        (
688
            SELECT
689
                indrelid
690
                , (regexp_matches(indexprs, E':varattno (\\\\d+)', 'g'))[1]::int
691
                    AS indkey
692
            FROM pg_index
693
            JOIN pg_class index ON index.oid = indexrelid
694
            JOIN pg_class table_ ON table_.oid = indrelid
695
            WHERE
696
                table_.relname = %(table)s
697
                AND index.relname = %(index)s
698
        ) s
699
        JOIN pg_attribute ON attrelid = indrelid AND attnum = indkey
700
) s
701 853 aaronmk
ORDER BY attnum
702
''',
703 1909 aaronmk
            {'table': table, 'index': index}, cacheable=True)))
704
    else: raise NotImplementedError("Can't list index columns for "+module+
705
        ' database')
706 853 aaronmk
707 464 aaronmk
def constraint_cols(db, table, constraint):
708 1849 aaronmk
    module = util.root_module(db.db)
709 464 aaronmk
    if module == 'psycopg2':
710
        return list(values(run_query(db, '''\
711
SELECT attname
712
FROM pg_constraint
713
JOIN pg_class ON pg_class.oid = conrelid
714
JOIN pg_attribute ON attrelid = conrelid AND attnum = ANY (conkey)
715
WHERE
716
    relname = %(table)s
717
    AND conname = %(constraint)s
718
ORDER BY attnum
719
''',
720
            {'table': table, 'constraint': constraint})))
721
    else: raise NotImplementedError("Can't list constraint columns for "+module+
722
        ' database')
723
724 2096 aaronmk
row_num_col = '_row_num'
725
726 2086 aaronmk
def add_row_num(db, table):
727 2117 aaronmk
    '''Adds a row number column to a table. Its name is in row_num_col. It will
728
    be the primary key.'''
729 2320 aaronmk
    table = sql_gen.as_Table(table).to_str(db)
730 2096 aaronmk
    run_query(db, 'ALTER TABLE '+table+' ADD COLUMN '+row_num_col
731 2117 aaronmk
        +' serial NOT NULL PRIMARY KEY')
732 2086 aaronmk
733 1968 aaronmk
def tables(db, schema='public', table_like='%'):
734 1849 aaronmk
    module = util.root_module(db.db)
735 1968 aaronmk
    params = {'schema': schema, 'table_like': table_like}
736 832 aaronmk
    if module == 'psycopg2':
737 1968 aaronmk
        return values(run_query(db, '''\
738
SELECT tablename
739
FROM pg_tables
740
WHERE
741
    schemaname = %(schema)s
742
    AND tablename LIKE %(table_like)s
743
ORDER BY tablename
744
''',
745
            params, cacheable=True))
746
    elif module == 'MySQLdb':
747
        return values(run_query(db, 'SHOW TABLES LIKE %(table_like)s', params,
748
            cacheable=True))
749 832 aaronmk
    else: raise NotImplementedError("Can't list tables for "+module+' database')
750 830 aaronmk
751 833 aaronmk
##### Database management
752
753 1968 aaronmk
def empty_db(db, schema='public', **kw_args):
754
    '''For kw_args, see tables()'''
755
    for table in tables(db, schema, **kw_args): truncate(db, table, schema)
756 833 aaronmk
757 832 aaronmk
##### Heuristic queries
758
759 2104 aaronmk
def put(db, table, row, pkey_=None, row_ct_ref=None):
760 1554 aaronmk
    '''Recovers from errors.
761 2077 aaronmk
    Only works under PostgreSQL (uses INSERT RETURNING).
762
    '''
763 2104 aaronmk
    if pkey_ == None: pkey_ = pkey(db, table, recover=True)
764
765 471 aaronmk
    try:
766 2149 aaronmk
        cur = insert(db, table, row, pkey_, recover=True)
767 1554 aaronmk
        if row_ct_ref != None and cur.rowcount >= 0:
768
            row_ct_ref[0] += cur.rowcount
769
        return value(cur)
770 471 aaronmk
    except DuplicateKeyException, e:
771 2104 aaronmk
        return value(select(db, table, [pkey_],
772 1069 aaronmk
            util.dict_subset_right_join(row, e.cols), recover=True))
773 471 aaronmk
774 473 aaronmk
def get(db, table, row, pkey, row_ct_ref=None, create=False):
775 830 aaronmk
    '''Recovers from errors'''
776 2209 aaronmk
    try: return value(select(db, table, [pkey], row, limit=1, recover=True))
777 14 aaronmk
    except StopIteration:
778 40 aaronmk
        if not create: raise
779 471 aaronmk
        return put(db, table, row, pkey, row_ct_ref) # insert new row
780 2078 aaronmk
781 2134 aaronmk
def put_table(db, out_table, in_tables, mapping, limit=None, start=0,
782 2279 aaronmk
    row_ct_ref=None):
783 2078 aaronmk
    '''Recovers from errors.
784
    Only works under PostgreSQL (uses INSERT RETURNING).
785 2131 aaronmk
    @param in_tables The main input table to select from, followed by a list of
786
        tables to join with it using the main input table's pkey
787 2312 aaronmk
    @param mapping dict(out_table_col=in_table_col, ...)
788
        * out_table_col: sql_gen.Col|str
789 2323 aaronmk
        * in_table_col: sql_gen.Col Wrap literal values in a sql_gen.NamedCol
790 2312 aaronmk
    @return sql_gen.Col Where the output pkeys are made available
791 2078 aaronmk
    '''
792 2329 aaronmk
    out_table = sql_gen.as_Table(out_table)
793 2312 aaronmk
    for in_table_col in mapping.itervalues():
794
        assert isinstance(in_table_col, sql_gen.Col)
795
796 2329 aaronmk
    temp_prefix = out_table.name
797 2387 aaronmk
    pkeys = sql_gen.Table(temp_prefix+'_pkeys')
798 2131 aaronmk
799 2382 aaronmk
    # Create input joins from list of input tables
800
    in_tables_ = in_tables[:] # don't modify input!
801
    in_tables0 = in_tables_.pop(0) # first table is separate
802 2279 aaronmk
    in_pkey = pkey(db, in_tables0, recover=True)
803 2285 aaronmk
    in_pkey_col = sql_gen.as_Col(in_pkey, in_tables0)
804 2352 aaronmk
    input_joins = [in_tables0]+[sql_gen.Join(v, {in_pkey: sql_gen.join_same})
805 2382 aaronmk
        for v in in_tables_]
806 2131 aaronmk
807 2279 aaronmk
    out_pkey = pkey(db, out_table, recover=True)
808 2285 aaronmk
    out_pkey_col = sql_gen.as_Col(out_pkey, out_table)
809 2142 aaronmk
810 2387 aaronmk
    pkeys_names = [in_pkey, out_pkey]
811 2236 aaronmk
    pkeys_cols = [in_pkey_col, out_pkey_col]
812
813 2201 aaronmk
    pkeys_table_exists_ref = [False]
814
    def run_query_into_pkeys(query, params):
815
        if pkeys_table_exists_ref[0]:
816 2387 aaronmk
            insert_select(db, pkeys, pkeys_names, query, params)
817 2201 aaronmk
        else:
818 2387 aaronmk
            run_query_into(db, query, params, into=pkeys)
819 2201 aaronmk
            pkeys_table_exists_ref[0] = True
820
821 2380 aaronmk
    conds = set()
822 2233 aaronmk
    distinct_on = []
823 2325 aaronmk
    def mk_main_select(joins, cols):
824
        return mk_select(db, joins, cols, conds, distinct_on, limit=limit,
825
            start=start, default_table=in_tables0)
826 2132 aaronmk
827 2309 aaronmk
    def log_exc(e):
828
        db.log_debug('Caught exception: '+exc.str_(e, first_line_only=True))
829 2358 aaronmk
    def ignore(in_col, value):
830 2365 aaronmk
        db.log_debug('Ignoring rows with '+str(in_col)+' = '+repr(value))
831 2378 aaronmk
        cond = (in_col, sql_gen.CompareCond(value, '!='))
832
        assert cond not in conds # avoid infinite loops
833 2380 aaronmk
        conds.add(cond)
834 2245 aaronmk
835 2206 aaronmk
    # Do inserts and selects
836 2257 aaronmk
    join_cols = {}
837 2387 aaronmk
    out_pkeys = sql_gen.Table(temp_prefix+'_out_pkeys')
838
    in_pkeys = sql_gen.Table(temp_prefix+'_in_pkeys')
839 2206 aaronmk
    while True:
840 2303 aaronmk
        has_joins = join_cols != {}
841
842 2305 aaronmk
        # Prepare to insert new rows
843 2325 aaronmk
        insert_joins = input_joins[:] # don't modify original!
844
        insert_args = dict(recover=True)
845 2303 aaronmk
        if has_joins:
846 2317 aaronmk
            distinct_on = [v.to_Col() for v in join_cols.values()]
847 2325 aaronmk
            insert_joins.append(sql_gen.Join(out_table, join_cols,
848
                sql_gen.filter_out))
849
        else:
850 2387 aaronmk
            insert_args.update(dict(returning=out_pkey, into=out_pkeys))
851 2303 aaronmk
852 2305 aaronmk
        db.log_debug('Inserting new rows')
853 2206 aaronmk
        try:
854
            cur = insert_select(db, out_table, mapping.keys(),
855 2325 aaronmk
                *mk_main_select(insert_joins, mapping.values()), **insert_args)
856 2357 aaronmk
            break # insert successful
857 2206 aaronmk
        except DuplicateKeyException, e:
858 2309 aaronmk
            log_exc(e)
859
860 2258 aaronmk
            old_join_cols = join_cols.copy()
861 2334 aaronmk
            join_cols.update(util.dict_subset(mapping, e.cols))
862 2245 aaronmk
            db.log_debug('Ignoring existing rows, comparing on '+str(join_cols))
863 2258 aaronmk
            assert join_cols != old_join_cols # avoid infinite loops
864 2230 aaronmk
        except NullValueException, e:
865 2309 aaronmk
            log_exc(e)
866
867 2230 aaronmk
            out_col, = e.cols
868
            try: in_col = mapping[out_col]
869 2356 aaronmk
            except KeyError:
870
                db.log_debug('Missing mapping for NOT NULL '+out_col)
871
                limit = 0 # just create an empty pkeys table
872 2365 aaronmk
            else: ignore(in_col, None)
873 2243 aaronmk
        except FunctionValueException, e:
874 2309 aaronmk
            log_exc(e)
875
876 2344 aaronmk
            assert e.name == out_table.name
877 2243 aaronmk
            out_col = 'value' # assume function param was named "value"
878 2358 aaronmk
            ignore(mapping[out_col], e.value)
879
        # after exception handled, rerun loop with additional constraints
880 2132 aaronmk
881 2357 aaronmk
    if row_ct_ref != None and cur.rowcount >= 0:
882
        row_ct_ref[0] += cur.rowcount
883
884
    if has_joins:
885
        select_joins = input_joins+[sql_gen.Join(out_table, join_cols)]
886
        db.log_debug('Getting output pkeys of existing/inserted rows')
887 2387 aaronmk
        run_query_into_pkeys(*mk_select(db, select_joins, pkeys_cols, start=0))
888 2357 aaronmk
    else:
889 2387 aaronmk
        add_row_num(db, out_pkeys) # for joining with input pkeys
890 2357 aaronmk
891
        db.log_debug('Getting input pkeys for rows in insert')
892
        run_query_into(db, *mk_main_select(input_joins, [in_pkey]),
893 2387 aaronmk
            into=in_pkeys)
894
        add_row_num(db, in_pkeys) # for joining with output pkeys
895 2357 aaronmk
896
        db.log_debug('Joining together output and input pkeys')
897 2387 aaronmk
        pkey_joins = [in_pkeys, sql_gen.Join(out_pkeys,
898 2357 aaronmk
            {row_num_col: sql_gen.join_same_not_null})]
899 2387 aaronmk
        run_query_into_pkeys(*mk_select(db, pkey_joins, pkeys_names, start=0))
900 2357 aaronmk
901
    db.log_debug("Setting missing rows' pkeys to NULL")
902 2387 aaronmk
    missing_rows_joins = input_joins+[sql_gen.Join(pkeys,
903 2357 aaronmk
        {in_pkey: sql_gen.join_same_not_null}, sql_gen.filter_out)]
904
        # must use join_same_not_null or query will take forever
905
    run_query_into_pkeys(*mk_select(db, missing_rows_joins,
906
        [in_pkey_col, sql_gen.NamedCol(out_pkey, None)], start=0))
907
908 2387 aaronmk
    return sql_gen.Col(out_pkey, pkeys)
909 2115 aaronmk
910
##### Data cleanup
911
912 2290 aaronmk
def cleanup_table(db, table, cols):
913 2115 aaronmk
    def esc_name_(name): return esc_name(db, name)
914
915 2290 aaronmk
    table = sql_gen.as_Table(table).to_str(db)
916 2115 aaronmk
    cols = map(esc_name_, cols)
917
918
    run_query(db, 'UPDATE '+table+' SET\n'+(',\n'.join(('\n'+col
919
        +' = nullif(nullif(trim(both from '+col+"), %(null0)s), %(null1)s)"
920
            for col in cols))),
921
        dict(null0='', null1=r'\N'))