diff options
Diffstat (limited to 'lib/sqlalchemy/sql/selectable.py')
| -rw-r--r-- | lib/sqlalchemy/sql/selectable.py | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/lib/sqlalchemy/sql/selectable.py b/lib/sqlalchemy/sql/selectable.py index f75613e35..ac955a60f 100644 --- a/lib/sqlalchemy/sql/selectable.py +++ b/lib/sqlalchemy/sql/selectable.py @@ -308,10 +308,34 @@ class FromClause(Selectable): _memoized_property = util.group_expirable_memoized_property(["_columns"]) + @util.deprecated( + '1.1', + message="``FromClause.count()`` is deprecated. Counting " + "rows requires that the correct column expression and " + "accommodations for joins, DISTINCT, etc. must be made, " + "otherwise results may not be what's expected. " + "Please use an appropriate ``func.count()`` expression " + "directly.") @util.dependencies("sqlalchemy.sql.functions") def count(self, functions, whereclause=None, **params): """return a SELECT COUNT generated against this - :class:`.FromClause`.""" + :class:`.FromClause`. + + The function generates COUNT against the + first column in the primary key of the table, or against + the first column in the table overall. Explicit use of + ``func.count()`` should be preferred:: + + row_count = conn.scalar( + select([func.count('*')]).select_from(table) + ) + + + .. seealso:: + + :data:`.func` + + """ if self.primary_key: col = list(self.primary_key)[0] @@ -1610,21 +1634,6 @@ class TableClause(Immutable, FromClause): else: return [] - @util.dependencies("sqlalchemy.sql.functions") - def count(self, functions, whereclause=None, **params): - """return a SELECT COUNT generated against this - :class:`.TableClause`.""" - - if self.primary_key: - col = list(self.primary_key)[0] - else: - col = list(self.columns)[0] - return Select( - [functions.func.count(col).label('tbl_row_count')], - whereclause, - from_obj=[self], - **params) - @util.dependencies("sqlalchemy.sql.dml") def insert(self, dml, values=None, inline=False, **kwargs): """Generate an :func:`.insert` construct against this |