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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 2393 aaronmk
def mk_flatten_mapping(db, into, cols, preserve=[]):
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 2390 aaronmk
    @param preserve [sql_gen.Col...] Columns not to rename. The tables of the
623 2392 aaronmk
        provided Col objects will be changed to into, so make copies of
624 2390 aaronmk
        them if you want to keep the original tables.
625 2383 aaronmk
    @return dict(orig_col=new_col, ...)
626
        * orig_col: sql_gen.Col(orig_col_name, orig_table)
627 2392 aaronmk
        * new_col: sql_gen.Col(orig_col_name, into)
628
        * All mappings use the into table so its name can easily be
629 2383 aaronmk
          changed for all columns at once
630
    '''
631
    flatten_mapping = {}
632 2393 aaronmk
    for col in cols: flatten_mapping[col] = sql_gen.Col(str(col), into)
633 2389 aaronmk
    for col in preserve:
634 2390 aaronmk
        orig_col = copy.copy(col)
635 2392 aaronmk
        col.table = into
636 2390 aaronmk
        flatten_mapping[orig_col] = col
637 2383 aaronmk
    return flatten_mapping
638
639 2393 aaronmk
def flatten(db, into, joins, cols, limit=None, start=None, **kw_args):
640 2391 aaronmk
    '''For params, see mk_flatten_mapping()
641
    @return See return value of mk_flatten_mapping()
642
    '''
643 2393 aaronmk
    mapping = mk_flatten_mapping(db, into, cols, **kw_args)
644 2391 aaronmk
    cols = [sql_gen.NamedCol(new.name, old) for old, new in mapping.iteritems()]
645
    run_query_into(db, *mk_select(db, joins, cols, limit=limit, start=start),
646 2392 aaronmk
        into=into)
647 2391 aaronmk
    return mapping
648
649 2291 aaronmk
def pkey(db, table, recover=None):
650 832 aaronmk
    '''Assumed to be first column in table'''
651 2339 aaronmk
    return table_cols(db, table, recover)[0]
652 832 aaronmk
653 2340 aaronmk
not_null_col = 'not_null'
654
655
def table_not_null_col(db, table, recover=None):
656
    '''Name assumed to be the value of not_null_col. If not found, uses pkey.'''
657
    if not_null_col in table_cols(db, table, recover): return not_null_col
658
    else: return pkey(db, table, recover)
659
660 853 aaronmk
def index_cols(db, table, index):
661
    '''Can also use this for UNIQUE constraints, because a UNIQUE index is
662
    automatically created. When you don't know whether something is a UNIQUE
663
    constraint or a UNIQUE index, use this function.'''
664 1909 aaronmk
    module = util.root_module(db.db)
665
    if module == 'psycopg2':
666
        return list(values(run_query(db, '''\
667 853 aaronmk
SELECT attname
668 866 aaronmk
FROM
669
(
670
        SELECT attnum, attname
671
        FROM pg_index
672
        JOIN pg_class index ON index.oid = indexrelid
673
        JOIN pg_class table_ ON table_.oid = indrelid
674
        JOIN pg_attribute ON attrelid = indrelid AND attnum = ANY (indkey)
675
        WHERE
676
            table_.relname = %(table)s
677
            AND index.relname = %(index)s
678
    UNION
679
        SELECT attnum, attname
680
        FROM
681
        (
682
            SELECT
683
                indrelid
684
                , (regexp_matches(indexprs, E':varattno (\\\\d+)', 'g'))[1]::int
685
                    AS indkey
686
            FROM pg_index
687
            JOIN pg_class index ON index.oid = indexrelid
688
            JOIN pg_class table_ ON table_.oid = indrelid
689
            WHERE
690
                table_.relname = %(table)s
691
                AND index.relname = %(index)s
692
        ) s
693
        JOIN pg_attribute ON attrelid = indrelid AND attnum = indkey
694
) s
695 853 aaronmk
ORDER BY attnum
696
''',
697 1909 aaronmk
            {'table': table, 'index': index}, cacheable=True)))
698
    else: raise NotImplementedError("Can't list index columns for "+module+
699
        ' database')
700 853 aaronmk
701 464 aaronmk
def constraint_cols(db, table, constraint):
702 1849 aaronmk
    module = util.root_module(db.db)
703 464 aaronmk
    if module == 'psycopg2':
704
        return list(values(run_query(db, '''\
705
SELECT attname
706
FROM pg_constraint
707
JOIN pg_class ON pg_class.oid = conrelid
708
JOIN pg_attribute ON attrelid = conrelid AND attnum = ANY (conkey)
709
WHERE
710
    relname = %(table)s
711
    AND conname = %(constraint)s
712
ORDER BY attnum
713
''',
714
            {'table': table, 'constraint': constraint})))
715
    else: raise NotImplementedError("Can't list constraint columns for "+module+
716
        ' database')
717
718 2096 aaronmk
row_num_col = '_row_num'
719
720 2086 aaronmk
def add_row_num(db, table):
721 2117 aaronmk
    '''Adds a row number column to a table. Its name is in row_num_col. It will
722
    be the primary key.'''
723 2320 aaronmk
    table = sql_gen.as_Table(table).to_str(db)
724 2096 aaronmk
    run_query(db, 'ALTER TABLE '+table+' ADD COLUMN '+row_num_col
725 2117 aaronmk
        +' serial NOT NULL PRIMARY KEY')
726 2086 aaronmk
727 1968 aaronmk
def tables(db, schema='public', table_like='%'):
728 1849 aaronmk
    module = util.root_module(db.db)
729 1968 aaronmk
    params = {'schema': schema, 'table_like': table_like}
730 832 aaronmk
    if module == 'psycopg2':
731 1968 aaronmk
        return values(run_query(db, '''\
732
SELECT tablename
733
FROM pg_tables
734
WHERE
735
    schemaname = %(schema)s
736
    AND tablename LIKE %(table_like)s
737
ORDER BY tablename
738
''',
739
            params, cacheable=True))
740
    elif module == 'MySQLdb':
741
        return values(run_query(db, 'SHOW TABLES LIKE %(table_like)s', params,
742
            cacheable=True))
743 832 aaronmk
    else: raise NotImplementedError("Can't list tables for "+module+' database')
744 830 aaronmk
745 833 aaronmk
##### Database management
746
747 1968 aaronmk
def empty_db(db, schema='public', **kw_args):
748
    '''For kw_args, see tables()'''
749
    for table in tables(db, schema, **kw_args): truncate(db, table, schema)
750 833 aaronmk
751 832 aaronmk
##### Heuristic queries
752
753 2104 aaronmk
def put(db, table, row, pkey_=None, row_ct_ref=None):
754 1554 aaronmk
    '''Recovers from errors.
755 2077 aaronmk
    Only works under PostgreSQL (uses INSERT RETURNING).
756
    '''
757 2104 aaronmk
    if pkey_ == None: pkey_ = pkey(db, table, recover=True)
758
759 471 aaronmk
    try:
760 2149 aaronmk
        cur = insert(db, table, row, pkey_, recover=True)
761 1554 aaronmk
        if row_ct_ref != None and cur.rowcount >= 0:
762
            row_ct_ref[0] += cur.rowcount
763
        return value(cur)
764 471 aaronmk
    except DuplicateKeyException, e:
765 2104 aaronmk
        return value(select(db, table, [pkey_],
766 1069 aaronmk
            util.dict_subset_right_join(row, e.cols), recover=True))
767 471 aaronmk
768 473 aaronmk
def get(db, table, row, pkey, row_ct_ref=None, create=False):
769 830 aaronmk
    '''Recovers from errors'''
770 2209 aaronmk
    try: return value(select(db, table, [pkey], row, limit=1, recover=True))
771 14 aaronmk
    except StopIteration:
772 40 aaronmk
        if not create: raise
773 471 aaronmk
        return put(db, table, row, pkey, row_ct_ref) # insert new row
774 2078 aaronmk
775 2134 aaronmk
def put_table(db, out_table, in_tables, mapping, limit=None, start=0,
776 2279 aaronmk
    row_ct_ref=None):
777 2078 aaronmk
    '''Recovers from errors.
778
    Only works under PostgreSQL (uses INSERT RETURNING).
779 2131 aaronmk
    @param in_tables The main input table to select from, followed by a list of
780
        tables to join with it using the main input table's pkey
781 2312 aaronmk
    @param mapping dict(out_table_col=in_table_col, ...)
782
        * out_table_col: sql_gen.Col|str
783 2323 aaronmk
        * in_table_col: sql_gen.Col Wrap literal values in a sql_gen.NamedCol
784 2312 aaronmk
    @return sql_gen.Col Where the output pkeys are made available
785 2078 aaronmk
    '''
786 2329 aaronmk
    out_table = sql_gen.as_Table(out_table)
787 2312 aaronmk
    for in_table_col in mapping.itervalues():
788
        assert isinstance(in_table_col, sql_gen.Col)
789
790 2329 aaronmk
    temp_prefix = out_table.name
791 2387 aaronmk
    pkeys = sql_gen.Table(temp_prefix+'_pkeys')
792 2131 aaronmk
793 2382 aaronmk
    # Create input joins from list of input tables
794
    in_tables_ = in_tables[:] # don't modify input!
795
    in_tables0 = in_tables_.pop(0) # first table is separate
796 2279 aaronmk
    in_pkey = pkey(db, in_tables0, recover=True)
797 2285 aaronmk
    in_pkey_col = sql_gen.as_Col(in_pkey, in_tables0)
798 2352 aaronmk
    input_joins = [in_tables0]+[sql_gen.Join(v, {in_pkey: sql_gen.join_same})
799 2382 aaronmk
        for v in in_tables_]
800 2131 aaronmk
801 2279 aaronmk
    out_pkey = pkey(db, out_table, recover=True)
802 2285 aaronmk
    out_pkey_col = sql_gen.as_Col(out_pkey, out_table)
803 2142 aaronmk
804 2387 aaronmk
    pkeys_names = [in_pkey, out_pkey]
805 2236 aaronmk
    pkeys_cols = [in_pkey_col, out_pkey_col]
806
807 2201 aaronmk
    pkeys_table_exists_ref = [False]
808
    def run_query_into_pkeys(query, params):
809
        if pkeys_table_exists_ref[0]:
810 2387 aaronmk
            insert_select(db, pkeys, pkeys_names, query, params)
811 2201 aaronmk
        else:
812 2387 aaronmk
            run_query_into(db, query, params, into=pkeys)
813 2201 aaronmk
            pkeys_table_exists_ref[0] = True
814
815 2380 aaronmk
    conds = set()
816 2233 aaronmk
    distinct_on = []
817 2325 aaronmk
    def mk_main_select(joins, cols):
818
        return mk_select(db, joins, cols, conds, distinct_on, limit=limit,
819
            start=start, default_table=in_tables0)
820 2132 aaronmk
821 2309 aaronmk
    def log_exc(e):
822
        db.log_debug('Caught exception: '+exc.str_(e, first_line_only=True))
823 2358 aaronmk
    def ignore(in_col, value):
824 2365 aaronmk
        db.log_debug('Ignoring rows with '+str(in_col)+' = '+repr(value))
825 2378 aaronmk
        cond = (in_col, sql_gen.CompareCond(value, '!='))
826
        assert cond not in conds # avoid infinite loops
827 2380 aaronmk
        conds.add(cond)
828 2245 aaronmk
829 2206 aaronmk
    # Do inserts and selects
830 2257 aaronmk
    join_cols = {}
831 2387 aaronmk
    out_pkeys = sql_gen.Table(temp_prefix+'_out_pkeys')
832
    in_pkeys = sql_gen.Table(temp_prefix+'_in_pkeys')
833 2206 aaronmk
    while True:
834 2303 aaronmk
        has_joins = join_cols != {}
835
836 2305 aaronmk
        # Prepare to insert new rows
837 2325 aaronmk
        insert_joins = input_joins[:] # don't modify original!
838
        insert_args = dict(recover=True)
839 2303 aaronmk
        if has_joins:
840 2317 aaronmk
            distinct_on = [v.to_Col() for v in join_cols.values()]
841 2325 aaronmk
            insert_joins.append(sql_gen.Join(out_table, join_cols,
842
                sql_gen.filter_out))
843
        else:
844 2387 aaronmk
            insert_args.update(dict(returning=out_pkey, into=out_pkeys))
845 2303 aaronmk
846 2305 aaronmk
        db.log_debug('Inserting new rows')
847 2206 aaronmk
        try:
848
            cur = insert_select(db, out_table, mapping.keys(),
849 2325 aaronmk
                *mk_main_select(insert_joins, mapping.values()), **insert_args)
850 2357 aaronmk
            break # insert successful
851 2206 aaronmk
        except DuplicateKeyException, e:
852 2309 aaronmk
            log_exc(e)
853
854 2258 aaronmk
            old_join_cols = join_cols.copy()
855 2334 aaronmk
            join_cols.update(util.dict_subset(mapping, e.cols))
856 2245 aaronmk
            db.log_debug('Ignoring existing rows, comparing on '+str(join_cols))
857 2258 aaronmk
            assert join_cols != old_join_cols # avoid infinite loops
858 2230 aaronmk
        except NullValueException, e:
859 2309 aaronmk
            log_exc(e)
860
861 2230 aaronmk
            out_col, = e.cols
862
            try: in_col = mapping[out_col]
863 2356 aaronmk
            except KeyError:
864
                db.log_debug('Missing mapping for NOT NULL '+out_col)
865
                limit = 0 # just create an empty pkeys table
866 2365 aaronmk
            else: ignore(in_col, None)
867 2243 aaronmk
        except FunctionValueException, e:
868 2309 aaronmk
            log_exc(e)
869
870 2344 aaronmk
            assert e.name == out_table.name
871 2243 aaronmk
            out_col = 'value' # assume function param was named "value"
872 2358 aaronmk
            ignore(mapping[out_col], e.value)
873
        # after exception handled, rerun loop with additional constraints
874 2132 aaronmk
875 2357 aaronmk
    if row_ct_ref != None and cur.rowcount >= 0:
876
        row_ct_ref[0] += cur.rowcount
877
878
    if has_joins:
879
        select_joins = input_joins+[sql_gen.Join(out_table, join_cols)]
880
        db.log_debug('Getting output pkeys of existing/inserted rows')
881 2387 aaronmk
        run_query_into_pkeys(*mk_select(db, select_joins, pkeys_cols, start=0))
882 2357 aaronmk
    else:
883 2387 aaronmk
        add_row_num(db, out_pkeys) # for joining with input pkeys
884 2357 aaronmk
885
        db.log_debug('Getting input pkeys for rows in insert')
886
        run_query_into(db, *mk_main_select(input_joins, [in_pkey]),
887 2387 aaronmk
            into=in_pkeys)
888
        add_row_num(db, in_pkeys) # for joining with output pkeys
889 2357 aaronmk
890
        db.log_debug('Joining together output and input pkeys')
891 2387 aaronmk
        pkey_joins = [in_pkeys, sql_gen.Join(out_pkeys,
892 2357 aaronmk
            {row_num_col: sql_gen.join_same_not_null})]
893 2387 aaronmk
        run_query_into_pkeys(*mk_select(db, pkey_joins, pkeys_names, start=0))
894 2357 aaronmk
895
    db.log_debug("Setting missing rows' pkeys to NULL")
896 2387 aaronmk
    missing_rows_joins = input_joins+[sql_gen.Join(pkeys,
897 2357 aaronmk
        {in_pkey: sql_gen.join_same_not_null}, sql_gen.filter_out)]
898
        # must use join_same_not_null or query will take forever
899
    run_query_into_pkeys(*mk_select(db, missing_rows_joins,
900
        [in_pkey_col, sql_gen.NamedCol(out_pkey, None)], start=0))
901
902 2387 aaronmk
    return sql_gen.Col(out_pkey, pkeys)
903 2115 aaronmk
904
##### Data cleanup
905
906 2290 aaronmk
def cleanup_table(db, table, cols):
907 2115 aaronmk
    def esc_name_(name): return esc_name(db, name)
908
909 2290 aaronmk
    table = sql_gen.as_Table(table).to_str(db)
910 2115 aaronmk
    cols = map(esc_name_, cols)
911
912
    run_query(db, 'UPDATE '+table+' SET\n'+(',\n'.join(('\n'+col
913
        +' = nullif(nullif(trim(both from '+col+"), %(null0)s), %(null1)s)"
914
            for col in cols))),
915
        dict(null0='', null1=r'\N'))