September 2010
Intermediate to advanced
440 pages
9h 23m
English
Content preview from MySQL for PythonBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Doing it in Python
As we have seen in previous chapters, processing a SELECT query in Python is as simple as execute() and fetchall(). However, Python also allows us to build statements dynamically, and this applies to joins, unions, and subqueries as well.
Subqueries
If we want column from table1, but the column reference for the subquery is colref, from both table1 and table2, we can write the following:
#!/usr/bin/env python import MySQLdb mydb = MySQLdb.connect('localhost', 'skipper', 'secret', 'sakila') cursor = mydb.cursor() table1 = 'film' table2 = 'film_actor' column = 'film_id, title' colref = 'film_id' statement = "SELECT %s FROM %s WHERE %s IN (SELECT %s FROM %s)" %(column, table1, colref, colref, table2) cursor.execute(statement) results ...Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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