Python MYSQL update statement

问题

I\'m trying to get this Python MYSQL update statement correct(With Variables):

cursor.execute (\"UPDATE tblTableName SET Year=%s\" % Year \", Month=%s\" % Month \", Day=%s\" % Day \", Hour=%s\" % Hour \", Minute=%s\" Minute \"WHERE Server=%s \" % ServerID)   

Any ideas where I\'m going wrong?

回答1:

It should be:

cursor.execute ("""
   UPDATE tblTableName
   SET Year=%s, Month=%s, Day=%s, Hour=%s, Minute=%s
   WHERE Server=%s
""", (Year, Month, Day, Hour, Minute, ServerID))

You can also do it with basic string manipulation,

cursor.execute ("UPDATE tblTableName SET Year=%s, Month=%s, Day=%s, Hour=%s, Minute=%s WHERE Server='%s' " % (Year, Month, Day, Hour, Minute, ServerID))

but this way is discouraged because it leaves you open for SQL Injection. As it's so easy (and similar) to do it the right way^tm. Do it correctly.

The only thing you should be careful, is that some database backends don't follow the same convention for string replacement (SQLite comes to mind).

回答2:

You've got the syntax all wrong:

cursor.execute ("""
   UPDATE tblTableName
   SET Year=%s, Month=%s, Day=%s, Hour=%s, Minute=%s
   WHERE Server=%s
""", (Year, Month, Day, Hour, Minute, ServerID))

For more, read the documentation.

回答3:

Here is the correct way：

import MySQLdb

if __name__ == '__main__':
    connect = MySQLdb.connect(host="localhost", port=3306,
                              user="xxx", passwd="xxx", db='xxx', charset='utf8')

    cursor = connect.cursor()

    cursor.execute("""
       UPDATE tblTableName
       SET Year=%s, Month=%s, Day=%s, Hour=%s, Minute=%s
       WHERE Server=%s
    """, (Year, Month, Day, Hour, Minute, ServerID))

    connect.commit()
    connect.close()

P.S. Don't forget connect.commit(), or it won't work

回答4:

Neither of them worked for me for some reason.

I figured it out that for some reason python doesn't read %s. So use (?) instead of %S in you SQL Code.

And finally this worked for me.

   cursor.execute ("update tablename set columnName = (?) where ID = (?) ",("test4","4"))
   connect.commit()

回答5:

@Esteban Küber is absolutely right.

Maybe one additional hint for bloody beginners like me. If you speciify the variables with %s, you have to follow this principle for EVERY input value, which means for the SET-variables as well as for the WHERE-variables.

Otherwise, you will have to face a termination message like 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '%s WHERE'

来源：https://stackoverflow.com/questions/1307378/python-mysql-update-statement