本文整理汇总了Python中sqlalchemy.sql.expression.Join方法的典型用法代码示例。如果您正苦于以下问题：Python expression.Join方法的具体用法？Python expression.Join怎么用？Python expression.Join使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类sqlalchemy.sql.expression的用法示例。
在下文中一共展示了expression.Join方法的3个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: _get_nonansi_join_whereclause
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import Join [as 别名]
def _get_nonansi_join_whereclause(self, froms):
clauses = []
def visit_join(join):
if join.isouter:
def visit_binary(binary):
if binary.operator == sql_operators.eq:
if join.right.is_derived_from(binary.left.table):
binary.left = _OuterJoinColumn(binary.left)
elif join.right.is_derived_from(binary.right.table):
binary.right = _OuterJoinColumn(binary.right)
clauses.append(visitors.cloned_traverse(
join.onclause, {}, {'binary': visit_binary}))
else:
clauses.append(join.onclause)
for j in join.left, join.right:
if isinstance(j, expression.Join):
visit_join(j)
elif isinstance(j, expression.FromGrouping):
visit_join(j.element)
for f in froms:
if isinstance(f, expression.Join):
visit_join(f)
if not clauses:
return None
else:
return sql.and_(*clauses) 示例2: _get_nonansi_join_whereclause
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import Join [as 别名]
def _get_nonansi_join_whereclause(self, froms):
clauses = []
def visit_join(join):
if join.isouter:
# https://docs.oracle.com/database/121/SQLRF/queries006.htm#SQLRF52354
# "apply the outer join operator (+) to all columns of B in
# the join condition in the WHERE clause" - that is,
# unconditionally regardless of operator or the other side
def visit_binary(binary):
if isinstance(binary.left, expression.ColumnClause) \
and join.right.is_derived_from(binary.left.table):
binary.left = _OuterJoinColumn(binary.left)
elif isinstance(binary.right, expression.ColumnClause) \
and join.right.is_derived_from(binary.right.table):
binary.right = _OuterJoinColumn(binary.right)
clauses.append(visitors.cloned_traverse(
join.onclause, {}, {'binary': visit_binary}))
else:
clauses.append(join.onclause)
for j in join.left, join.right:
if isinstance(j, expression.Join):
visit_join(j)
elif isinstance(j, expression.FromGrouping):
visit_join(j.element)
for f in froms:
if isinstance(f, expression.Join):
visit_join(f)
if not clauses:
return None
else:
return sql.and_(*clauses) 示例3: _get_nonansi_join_whereclause
# 需要导入模块: from sqlalchemy.sql import expression [as 别名]
# 或者: from sqlalchemy.sql.expression import Join [as 别名]
def _get_nonansi_join_whereclause(self, froms):
clauses = []
def visit_join(join):
if join.isouter:
def visit_binary(binary):
if binary.operator == sql_operators.eq:
if join.right.is_derived_from(binary.left.table):
binary.left = _OuterJoinColumn(binary.left)
elif join.right.is_derived_from(binary.right.table):
binary.right = _OuterJoinColumn(binary.right)
clauses.append(visitors.cloned_traverse(join.onclause, {},
{'binary': visit_binary}))
else:
clauses.append(join.onclause)
for j in join.left, join.right:
if isinstance(j, expression.Join):
visit_join(j)
elif isinstance(j, expression.FromGrouping):
visit_join(j.element)
for f in froms:
if isinstance(f, expression.Join):
visit_join(f)
if not clauses:
return None
else:
return sql.and_(*clauses)