Python cx_Oracle 中 Oracle Prepared Statement 的 IN 子句

Question

I'd like to use the IN clause with a prepared Oracle statement using cx_Oracle in Python.

Eg query - select name from employee where id in ('101', '102', '103')

On python side, I have a list [101, 102, 103] which I converted to a string like this ('101', '102', '103') and used the following code in python -

import cx_Oracle
ids = [101, 102, 103]
ALL_IDS = "('{0}')".format("','".join(map(str, ids)))
conn = cx_Oracle.connect('username', 'pass', 'schema')
cursor = conn.cursor()
results = cursor.execute('select name from employee where id in :id_list', id_list=ALL_IDS)
names = [x[0] for x in cursor.description]
rows = results.fetchall()

This doesn't work. Am I doing something wrong?

Answer 1

This concept is not supported by Oracle -- and you are definitely not the first person to try this approach either! You must either:

• create separate bind variables for each in value -- something that is fairly easy and straightforward to do in Python

• create a subquery using the cast operator on Oracle types as is shown in this post: https://asktom.oracle.com/pls/asktom/f?p=100:11:0::::p11_question_id:210612357425

• use a stored procedure to accept the array and perform multiple queries directly within PL/SQL

• or do something else entirely!

Answer 2

Otra opción es dar formato a una cadena con la consulta.

import cx_Oracle
ids = [101, 102, 103]
ALL_IDS = "('{0}')".format("','".join(map(str, ids)))
conn = cx_Oracle.connect('username', 'pass', 'schema')
cursor = conn.cursor()

query = """
select name from employee where id in ('{}')
""".format("','".join(map(str, ids)))

results = cursor.execute(query)
names = [x[0] for x in cursor.description]
rows = results.fetchall()

Answer 3

Just transform your list into a tuple and format the sql string with it

ids = [101, 102, 103]
param = tuple(ids)
results = cursor.execute("select name from employee where id IN {}".format(param))

Answer 4

Since you created the string, you're almost there. This should work:

results = cursor.execute('select name from employee where id in ' + ALL_IDS)