Revision 2394
Added by Aaron Marcuse-Kubitza about 12 years ago
| lib/sql.py | ||
|---|---|---|
| 614 | 614 |
return list(col_names(select(db, table, limit=0, order_by=None, |
| 615 | 615 |
recover=recover))) |
| 616 | 616 |
|
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def mk_flatten_mapping(db, into, cols, preserve=[]): |
|
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def mk_flatten_mapping(db, into, cols, preserve=[], as_items=False):
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| 618 | 618 |
'''Creates a mapping from original column names (which may have collisions) |
| 619 | 619 |
to names that will be distinct among the given tables. |
| 620 | 620 |
This is meant to be used for several tables that are being joined together. |
| 621 | 621 |
@param into The table for the new columns |
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@param preserve [sql_gen.Col...] Columns not to rename. The tables of the |
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provided Col objects will be changed to into, so make copies of |
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them if you want to keep the original tables. |
|
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@param preserve [sql_gen.Col...] Columns not to rename. Note that these |
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columns will be included in the mapping even if they are not in cols. |
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The tables of the provided Col objects will be changed to into, so make |
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copies of them if you want to keep the original tables. |
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@param as_items Whether to return a list of dict items instead of a dict |
|
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@return dict(orig_col=new_col, ...) |
| 626 | 628 |
* orig_col: sql_gen.Col(orig_col_name, orig_table) |
| 627 | 629 |
* new_col: sql_gen.Col(orig_col_name, into) |
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* All mappings use the into table so its name can easily be |
| 629 | 631 |
changed for all columns at once |
| 630 | 632 |
''' |
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flatten_mapping = {}
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for col in cols: flatten_mapping[col] = sql_gen.Col(str(col), into) |
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items = [] |
|
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for col in preserve: |
| 634 | 635 |
orig_col = copy.copy(col) |
| 635 | 636 |
col.table = into |
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flatten_mapping[orig_col] = col |
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return flatten_mapping |
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items.append((orig_col, col)) |
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preserve = set(preserve) |
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for col in cols: |
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if col not in preserve: items.append((col, sql_gen.Col(str(col), into))) |
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|
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if not as_items: items = dict(items) |
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return items |
|
| 638 | 644 |
|
| 639 | 645 |
def flatten(db, into, joins, cols, limit=None, start=None, **kw_args): |
| 640 | 646 |
'''For params, see mk_flatten_mapping() |
| 641 | 647 |
@return See return value of mk_flatten_mapping() |
| 642 | 648 |
''' |
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mapping = mk_flatten_mapping(db, into, cols, **kw_args)
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cols = [sql_gen.NamedCol(new.name, old) for old, new in mapping.iteritems()]
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items = mk_flatten_mapping(db, into, cols, as_items=True, **kw_args)
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cols = [sql_gen.NamedCol(new.name, old) for old, new in items]
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| 645 | 651 |
run_query_into(db, *mk_select(db, joins, cols, limit=limit, start=start), |
| 646 | 652 |
into=into) |
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return mapping
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return dict(items)
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| 648 | 654 |
|
| 649 | 655 |
def pkey(db, table, recover=None): |
| 650 | 656 |
'''Assumed to be first column in table''' |
Also available in: Unified diff
sql.py: mk_flatten_mapping(): Take as_items param to return a list of dict items instead of a dict. Sort preserve cols before other cols. flatten(): Turn on as_items so that cols list is sorted in input order, with preserve cols first. This ensures that if a pkey is provided in preserve, it will be the first col in the generated table.