Question

I have a .sql file containing a bunch of SQL queries, with each query spanning multiple lines. I want to execute these queries in MySQL via Python using MySQLdb.

sqlite3 has “a nonstandard shortcut” for this purpose called executescript(), but there doesn’t seem to be any equivalent function in MySQLdb.

I noticed this old question from 2 years ago which asks the same thing, but I found the answers unsatisfying. The answers are basically:

Use subprocess to run the mysql command and send it your .sql file.

This works, but it is rather inelegant, and it introduces unwanted complexity with error handling and such.

If each query is on a single line, just execute each line separately.

But in my case, they span multiple lines, so this won’t work.

If each query is not on a single line, somehow join them.

But, how? I mean, I can hack up something easily enough so there’s no need for you to reply with half-baked answers here, and maybe that’s what I’ll end up doing, but is there already an established library that does this? I’d feel more comfortable with a comprehensive and correct solution rather than a hack.

Answer 1

MySQLdb seems to allow this out of the box, you just have to call cursor.nextset() to cycle through the returned result sets.

db = conn.cursor()
db.execute('SELECT 1; SELECT 2;')

more = True
while more:
    print db.fetchall()
    more = db.nextset()

If you want to be absolutely sure the support for this is enabled, and/or disable the support, you can use something like this:

MYSQL_OPTION_MULTI_STATEMENTS_ON = 0
MYSQL_OPTION_MULTI_STATEMENTS_OFF = 1

conn.set_server_option(MYSQL_OPTION_MULTI_STATEMENTS_ON)
# Multiple statement execution here...
conn.set_server_option(MYSQL_OPTION_MULTI_STATEMENTS_OFF)