mirror of
https://github.com/simonw/sqlite-utils.git
synced 2026-07-23 01:14:31 +02:00
Much, much faster extract() implementation
Takes my test down from ten minutes to four seconds! * Removed unnecessary update() optimization * Added column_order= to .transform() and .transform_sql() * Tests for reusing lookup table in extract() Closes #172
This commit is contained in:
Simon Willison
GitHub
parent
5eb14d1c1f
commit
022cdd97a9
3 changed files with 135 additions and 58 deletions
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@ -1006,12 +1006,6 @@ def transform(
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multiple=True,
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help="Rename this column in extracted table",
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)
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@click.option(
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"-s",
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"--silent",
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is_flag=True,
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help="Don't show progress bar",
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)
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def extract(
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path,
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table,
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@ -1019,7 +1013,6 @@ def extract(
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other_table,
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fk_column,
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rename,
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silent,
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):
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"Extract one or more columns into a separate table"
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db = sqlite_utils.Database(path)
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@ -1029,14 +1022,7 @@ def extract(
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fk_column=fk_column,
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rename=dict(rename),
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)
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if silent:
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db[table].extract(**kwargs)
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else:
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with click.progressbar(
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length=db[table].count, label="Extracting columns"
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) as bar:
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kwargs["progress"] = bar.update
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db[table].extract(**kwargs)
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db[table].extract(**kwargs)
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@cli.command(name="insert-files")
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@ -3,7 +3,6 @@ from collections import namedtuple, OrderedDict
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import contextlib
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import datetime
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import decimal
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import functools
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import hashlib
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import inspect
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import itertools
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@ -731,6 +730,7 @@ class Table(Queryable):
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not_null=None,
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defaults=None,
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drop_foreign_keys=None,
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column_order=None,
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):
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assert self.exists(), "Cannot transform a table that doesn't exist yet"
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sqls = self.transform_sql(
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@ -741,6 +741,7 @@ class Table(Queryable):
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not_null=not_null,
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defaults=defaults,
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drop_foreign_keys=drop_foreign_keys,
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column_order=column_order,
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)
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pragma_foreign_keys_was_on = self.db.execute("PRAGMA foreign_keys").fetchone()[
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0
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@ -769,6 +770,7 @@ class Table(Queryable):
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not_null=None,
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defaults=None,
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drop_foreign_keys=None,
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column_order=None,
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tmp_suffix=None,
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):
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types = types or {}
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@ -840,6 +842,9 @@ class Table(Queryable):
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(rename.get(column) or column, other_table, other_column)
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)
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if column_order is not None:
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column_order = [rename.get(col) or col for col in column_order]
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sqls.append(
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self.db.create_table_sql(
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new_table_name,
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@ -848,6 +853,7 @@ class Table(Queryable):
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not_null=create_table_not_null,
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defaults=create_table_defaults,
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foreign_keys=create_table_foreign_keys,
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column_order=column_order,
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).strip()
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)
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@ -872,7 +878,7 @@ class Table(Queryable):
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)
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return sqls
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def extract(self, columns, table=None, fk_column=None, rename=None, progress=None):
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def extract(self, columns, table=None, fk_column=None, rename=None):
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rename = rename or {}
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if isinstance(columns, str):
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columns = [columns]
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@ -886,38 +892,85 @@ class Table(Queryable):
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first_column = columns[0]
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pks = self.pks
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lookup_table = self.db[table]
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@functools.lru_cache(maxsize=128)
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def cached_lookup(lookups):
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return lookup_table.lookup(dict(lookups))
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if pks == ["rowid"]:
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rows_iter = self.rows_where(select="rowid, *")
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else:
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rows_iter = self.rows
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for row in rows_iter:
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row_pks = tuple(row[pk] for pk in pks)
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lookups = tuple(
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(rename.get(column) or column, row[column]) for column in columns
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)
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self.update(
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row_pks,
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{first_column: cached_lookup(lookups)},
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assume_exists=True,
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pks=self.pks,
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)
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if progress:
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progress(1)
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fk_column = fk_column or "{}_id".format(table)
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# Now rename first_column and change its type to integer, and drop
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# any other extracted columns:
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self.transform(
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types={first_column: int},
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drop=set(columns[1:]),
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rename={first_column: fk_column},
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magic_lookup_column = "{}_{}".format(fk_column, os.urandom(6).hex())
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# Populate the lookup table with all of the extracted unique values
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lookup_columns_definition = {
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(rename.get(col) or col): typ
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for col, typ in self.columns_dict.items()
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if col in columns
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}
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if lookup_table.exists():
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if not set(lookup_columns_definition.items()).issubset(
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lookup_table.columns_dict.items()
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):
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raise InvalidColumns(
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"Lookup table {} already exists but does not have columns {}".format(
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table, lookup_columns_definition
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)
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)
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else:
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lookup_table.create(
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{
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**{
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"id": int,
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},
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**lookup_columns_definition,
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},
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pk="id",
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)
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lookup_columns = [(rename.get(col) or col) for col in columns]
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lookup_table.create_index(lookup_columns, unique=True, if_not_exists=True)
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self.db.execute(
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"INSERT OR IGNORE INTO [{lookup_table}] ({lookup_columns}) SELECT DISTINCT {table_cols} FROM [{table}]".format(
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lookup_table=table,
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lookup_columns=", ".join("[{}]".format(c) for c in lookup_columns),
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table_cols=", ".join("[{}]".format(c) for c in columns),
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table=self.name,
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)
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)
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# Now add the new fk_column
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self.add_column(magic_lookup_column, int)
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# And populate it
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self.db.execute(
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"UPDATE [{table}] SET [{magic_lookup_column}] = (SELECT id FROM [{lookup_table}] WHERE {where})".format(
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table=self.name,
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magic_lookup_column=magic_lookup_column,
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lookup_table=table,
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where=" AND ".join(
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"[{table}].[{column}] = [{lookup_table}].[{lookup_column}]".format(
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table=self.name,
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lookup_table=table,
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column=column,
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lookup_column=rename.get(column) or column,
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)
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for column in columns
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),
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)
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)
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# Figure out the right column order
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column_order = []
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for c in self.columns:
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if c.name in columns and magic_lookup_column not in column_order:
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column_order.append(magic_lookup_column)
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elif c.name == magic_lookup_column:
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continue
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else:
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column_order.append(c.name)
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# Drop the unnecessary columns and rename lookup column
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self.transform(
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drop=set(columns),
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rename={magic_lookup_column: fk_column},
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column_order=column_order,
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)
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# And add the foreign key constraint
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self.add_foreign_key(fk_column, table, "id")
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return self
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def create_index(self, columns, index_name=None, unique=False, if_not_exists=False):
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if index_name is None:
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@ -1258,28 +1311,19 @@ class Table(Queryable):
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self.db.execute(sql, where_args or [])
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return self
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def update(
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self,
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pk_values,
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updates=None,
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alter=False,
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conversions=None,
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assume_exists=False,
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pks=None,
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):
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def update(self, pk_values, updates=None, alter=False, conversions=None):
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updates = updates or {}
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pks = pks or self.pks
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conversions = conversions or {}
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if not isinstance(pk_values, (list, tuple)):
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pk_values = [pk_values]
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# Soundness check that the record exists (raises error if not):
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if not assume_exists:
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self.get(pk_values)
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self.get(pk_values)
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if not updates:
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return self
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args = []
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sets = []
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wheres = []
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pks = self.pks
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validate_column_names(updates.keys())
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for key, value in updates.items():
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sets.append("[{}] = {}".format(key, conversions.get(key, "?")))
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