Update database with multiple SQL Statments

Question

I am using mysql connector.Python 1.0.9 downloaded from MySQL site.

I have a sample table here

DROP TABLE IF EXISTS my_table; 
CREATE TABLE my_table
(id INT NOT NULL AUTO_INCREMENT UNIQUE,
Shot VARCHAR(4),
sec varchar(5),
lay VARCHAR(15) NOT NULL,
lay_status VARCHAR(15) NOT NULL,
blk VARCHAR(10) NOT NULL,
blk_status VARCHAR(15) NOT NULL,
pri VARCHAR(10) NOT NULL,
pri_status VARCHAR(15) NOT NULL,
ani VARCHAR(10) NOT NULL,
ani_status VARCHAR(15) NOT NULL,
status VARCHAR(5)
);

INSERT INTO my_table VALUES
(1,'SH01','3','1863','yes','1863','yes','P4645','yes','P4557','yes','Over'),
(2,'SH02','2.5','1863','yes','P4645','no','P4557','yes','1863','no','Over'),
(3,'SH03','0.5','P4645','yes','P4557','yes','1863','yes','1863','yes','WIP'),
(4,'SH04','1.25','1863','no','P4645','no','P4557','yes','1863','yes','RTK'),
(5,'SH05','1','1863','yes','1863','yes','P4645','yes','P4557','yes','WIP'),
(6,'SH06','6','P4557','yes','P4645','yes','P4645','yes','P4557','yes','WIP');

i am able to execute a single SQL statment as below.

import mysql.connector

cnx = mysql.connector.connect(user='scott', database='test')
cursor = cnx.cursor()

SQL = '''
        update my_table 
        set 
        LAY = 'P6682'
        , BLK = 'P6682'
        , ANI = 'P6682'
        where
        Shot = 'SH01';
      '''

cursor.execute(SQL)

and everything is fine and database gets updated correctly.

now when i am trying to update the database with multiple statements as below

import mysql.connector

cnx = mysql.connector.connect(user='scott', database='test')
cursor = cnx.cursor()

SQL = '''
    update my_table 
    set 
    LAY = 'P6682'
    , BLK = 'P6682'
    , ANI = 'P6682'
    where
    Shot = 'SH01';

    update my_table 
    set 
    LAY = '1863'
    , BLK = '1863'
    , ANI = '1863'
    where
    Shot = 'SH02'
'''

cursor.execute(SQL)
cnx.commit()
cur.close()
cnx.close()
cnx.disconnect()

I get below trackback error

Traceback (most recent call last):
  File "Test_Module.py", line 24, in 
  File "C:\Python26\Lib\site-packages\mysql\connector\cursor.py", line 396, in execute
    "Use multi=True when executing multiple statements")
InterfaceError: Use multi=True when executing multiple statements

I update my command as below

cursor.execute(SQL,multi = True)

cnx.commit()
cur.close()
cnx.close()
cnx.disconnect()

Now i dont get any error/Traceback. But the database is not getting updated.

Can any one tell me where am i doing wrong.

Answer 1

At-last after a long research on docs and help. I could able to solve the issue.

Using a for loop at cursor.execute with multi=True worked. I don't know why we need to loop through.

for result in cursor.execute(SQL, multi=True):
    pass

Without loop just cursor.execute(SQL, multi=True) did not do any changes in the database.

import mysql.connector

cnx = mysql.connector.connect(user='scott', database='test')
cursor = cnx.cursor()

SQL = '''
    update my_table 
    set 
    LAY = 'P6682'
    , BLK = 'P6682'
    , ANI = 'P6682'
    where
    Shot = 'SH01';

    update my_table 
    set 
    LAY = '1863'
    , BLK = '1863'
    , ANI = '1863'
    where
    Shot = 'SH02'
'''

for result in cursor.execute(SQL, multi=True):
    pass

cnx.commit()
cur.close()
cnx.close()
cnx.disconnect()