Bulk update PostgreSQL from Python dict

Question

In an existing PostgreSQL table, I would like to UPDATE several existing columns with values from a dictionary lookup (see dict below). Somewhat like described in this nice blog post. However, I can't figure out how to do that with a Python dictionary. Here comes the terrible pseudo-code:

d = {10:'chair', 11:'table', 12:'lamp', 
    20:'english ivy', 21:'peace lily', 22:'spider plant'}

curs.execute("""
    UPDATE my_table t
    SET furniture = %(t.furniture)s,
    SET plant = %(t.plant)s""",
    d)

The original table would look somewhat like this:

gid | furniture | plant
-----------------------
 0  |    10     |  21
 1  |    11     |  20
 ...

After the operation it should look like this:

gid | furniture |    plant
-----------------------------
 0  |   chair   | peace lily
 1  |   table   | english ivy
 ...

Is this possible or will I have to loop through the table?

Answer 1

try this:

rows = (
    {'gid': 10, 'furniture': 10, 'plant': 10},
    {'gid': 20, 'furniture': 20, 'plant': 20}
)
cur.executemany(
    '''
        UPDATE myTable 
        SET
            furniture = %(furniture)s,
            plant = %(plant)s
        WHERE
            gid = %(gid)s
    ''',
    rows
)