使用python从Mysql表查询和检索数据

Question

I am trying to retrieve data from mysql table using python but keep getting an error. Please see my attempt below and the data:

import MySQLdb
# connect
db = MySQLdb.connect(host="localhost", user="root", passwd="xxxxxxx", db="world")
cursor = db.cursor()
t=['red', 'yellow']

for x in t:
    cursor.execute("select * from mytable where colours=%s," [x])

I got the following error: TypeError: string indices must be integers, not str

I learnt Mysql stores data as tuples, hence I would need change %s to a tuple but don't know how.

Any suggestions? thanks.

Answer 1

Try this and check if this resolve your problem

import MySQLdb
# connect
db = MySQLdb.connect(host="localhost", user="root", passwd="xxxxxxx", db="world")
cursor = db.cursor()
t=['red', 'yellow']

for x in t:
    cursor.execute("select * from mytable where colours=%s" % repr(x))

Please note that here the Sql Query will build like

select * from mytable where colours='red'   #which is actual and correct query

Though I have not tested yet and there could be alternate way of doing this. The actual problem with OP problem is that it build Sql Query like

select * from mytable where colours=red  # Check the missing quotation around text red

Answer 2

You want to iterate over the element in t . Therefore you do not need the [] around x :

import MySQLdb
# connect
db = MySQLdb.connect(host="localhost", user="root", passwd="xxxxxxx", db="world")
cursor = db.cursor()
t=['red', 'yellow']

for x in t:
    cursor.execute("select * from mytable where colours=%s", x)