def table_exprs(self):
'''Provides a list of all table_exprs that are declared within this FROM
block.
'''
table_exprs = \
TableExprList(join_clause.table_expr for join_clause in self.join_clauses)
table_exprs.append(self.table_expr)
return table_exprs
def table_exprs(self):
'''Provides a list of all table_exprs that are declared within this FROM
block.
'''
table_exprs = \
TableExprList(join_clause.table_expr for join_clause in self.join_clauses)
table_exprs.append(self.table_expr)
return table_exprs
def describe_common_tables(cursors):
'''Find and return a TableExprList containing Table objects that the given conns
have in common.
'''
common_table_names = None
for cursor in cursors:
table_names = set(cursor.list_table_names())
if common_table_names is None:
common_table_names = table_names
else:
common_table_names &= table_names
common_table_names = sorted(common_table_names)
tables = TableExprList()
for table_name in common_table_names:
common_table = None
mismatch = False
for cursor in cursors:
table = cursor.describe_table(table_name)
if common_table is None:
common_table = table
continue
if not table.cols:
LOG.debug('%s has no remaining columns', table_name)
mismatch = True
break
if len(common_table.cols) != len(table.cols):
LOG.debug(
'Ignoring table %s.'
' It has a different number of columns across databases.',
table_name)
mismatch = True
break
if common_table.primary_key_names != table.primary_key_names:
LOG.debug(
'Ignoring table {name} because of differing primary keys: '
'{common_table_keys} vs. {table_keys}'.format(
name=table_name,
common_table_keys=common_table.primary_key_names,
table_keys=table.primary_key_names))
mismatch = True
break
for left, right in izip(common_table.cols, table.cols):
if not left.name == right.name and left.type == right.type:
LOG.debug(
'Ignoring table %s. It has different columns %s vs %s.'
% (table_name, left, right))
mismatch = True
break
if mismatch:
break
if not mismatch:
tables.append(common_table)
return tables
def table_exprs(self):
"""
Return a list of all table expressions that are declared by this query. This is
abstract as the clauses that do this differ across query types. Since all supported
queries may have a WITH clause, getting table expressions from the WITH clause is
supported here.
"""
# This is an abstractproperty because it's only a *partial* implementation, however
# for any statement or query that has a WITH clause, we can handle that here.
table_exprs = TableExprList([])
if self.with_clause:
table_exprs.extend(self.with_clause.table_exprs)
return table_exprs
def describe_common_tables(cursors):
'''Find and return a TableExprList containing Table objects that the given conns
have in common.
'''
common_table_names = None
for cursor in cursors:
table_names = set(cursor.list_table_names())
if common_table_names is None:
common_table_names = table_names
else:
common_table_names &= table_names
common_table_names = sorted(common_table_names)
tables = TableExprList()
for table_name in common_table_names:
common_table = None
mismatch = False
for cursor in cursors:
table = cursor.describe_table(table_name)
if common_table is None:
common_table = table
continue
if not table.cols:
LOG.debug('%s has no remaining columns', table_name)
mismatch = True
break
if len(common_table.cols) != len(table.cols):
LOG.debug('Ignoring table %s.'
' It has a different number of columns across databases.', table_name)
mismatch = True
break
if common_table.primary_key_names != table.primary_key_names:
LOG.debug(
'Ignoring table {name} because of differing primary keys: '
'{common_table_keys} vs. {table_keys}'.format(
name=table_name, common_table_keys=common_table.primary_key_names,
table_keys=table.primary_key_names))
mismatch = True
break
for left, right in izip(common_table.cols, table.cols):
if not left.name == right.name and left.type == right.type:
LOG.debug('Ignoring table %s. It has different columns %s vs %s.' %
(table_name, left, right))
mismatch = True
break
if mismatch:
break
if not mismatch:
tables.append(common_table)
return tables
def visible_table_exprs(self):
'''Provides a list of all table_exprs that are declared within this FROM
block and may be referenced in other clauses such as SELECT or WHERE.
'''
return TableExprList(table_expr for table_expr in self.table_exprs
if table_expr.is_visible)