Enable executing multiple statements while execution via sqlalchemy

Question

I have a DDL object (create_function_foo) that contains a create function statement. In first line of it I put DROP FUNCTION IF EXISTS foo; but

Answer 1

There are some cases where SQLAlchemy does not provide a generic way at accessing some DBAPI functions, such as as dealing with multiple result sets. In these cases, you should deal with the raw DBAPI connection directly.

From SQLAlchemy documentation:

connection = engine.raw_connection()
try:
    cursor = connection.cursor()
    cursor.execute("select * from table1; select * from table2")
    results_one = cursor.fetchall()
    cursor.nextset()
    results_two = cursor.fetchall()
    cursor.close()
finally:
    connection.close()

You can also do the same using mysql connector as seen here:

operation = 'SELECT 1; INSERT INTO t1 VALUES (); SELECT 2'
for result in cursor.execute(operation, multi=True):
  if result.with_rows:
    print("Rows produced by statement '{}':".format(
      result.statement))
    print(result.fetchall())
  else:
    print("Number of rows affected by statement '{}': {}".format(
      result.statement, result.rowcount))

Answer 2

Yeah... This seems like a bummer to me. I don't want to use the ORM so the accepted answer didn't work for me.

I did this instead:

with open('sql_statements_file.sql') as sql_file:
    for statement in sql_file.read().split(';'):
        if len(statement.strip()) > 0:
             connection.execute(statement + ';')

And then this failed for a CREATE function.... YMMV.

Answer 3

multi=True is a requirement for MySql connector. You can not set this flag passing it to SQLAlchemy methods. Do this:

conn  = session.connection().connection
cursor = conn.cursor()  # get mysql db-api cursor
cursor.execute(sql, multi=True)

More info here: http://www.mail-archive.com/sqlalchemy@googlegroups.com/msg30129.html