[rql] Store selected variables for RQL select queries in ResultSet (#17218476)
By storing the name of the selected variables for RQL select queries in the
ResultSet (within the "variables" attribute), the information can be passed
down to specific protocols, e.g. rqlio that may wish to pass is down further
to clients.
In turn, clients can then choose to present the results of RQL select queries
as symbolic bindings using the names used in the query's projection, instead of
ordinal arrays.
from __future__ import print_function
def migrate_varchar_to_nvarchar():
dbdriver = config.system_source_config['db-driver']
if dbdriver != "sqlserver2005":
return
introspection_sql = """\
SELECT table_schema, table_name, column_name, is_nullable, character_maximum_length
FROM information_schema.columns
WHERE data_type = 'VARCHAR' and table_name <> 'SYSDIAGRAMS'
"""
has_index_sql = """\
SELECT i.name AS index_name,
i.type_desc,
i.is_unique,
i.is_unique_constraint
FROM sys.indexes AS i, sys.index_columns as j, sys.columns as k
WHERE is_hypothetical = 0 AND i.index_id <> 0
AND i.object_id = j.object_id
AND i.index_id = j.index_id
AND i.object_id = OBJECT_ID('%(table)s')
AND k.name = '%(col)s'
AND k.object_id=i.object_id
AND j.column_id = k.column_id;"""
generated_statements = []
for schema, table, column, is_nullable, length in sql(introspection_sql, ask_confirm=False):
qualified_table = '[%s].[%s]' % (schema, table)
rset = sql(has_index_sql % {'table': qualified_table, 'col':column},
ask_confirm = False)
drops = []
creates = []
for idx_name, idx_type, idx_unique, is_unique_constraint in rset:
if is_unique_constraint:
drops.append('ALTER TABLE %s DROP CONSTRAINT %s' % (qualified_table, idx_name))
creates.append('ALTER TABLE %s ADD CONSTRAINT %s UNIQUE (%s)' % (qualified_table, idx_name, column))
else:
drops.append('DROP INDEX %s ON %s' % (idx_name, qualified_table))
if idx_unique:
unique = 'UNIQUE'
else:
unique = ''
creates.append('CREATE %s %s INDEX %s ON %s(%s)' % (unique, idx_type, idx_name, qualified_table, column))
if length == -1:
length = 'max'
if is_nullable == 'YES':
not_null = 'NULL'
else:
not_null = 'NOT NULL'
alter_sql = 'ALTER TABLE %s ALTER COLUMN %s NVARCHAR(%s) %s' % (qualified_table, column, length, not_null)
generated_statements+= drops + [alter_sql] + creates
for statement in generated_statements:
print(statement)
sql(statement, ask_confirm=False)
commit()
migrate_varchar_to_nvarchar()