SELECT — Python Technical Interview Questions & Answers
SELECT
SELECT
- SELECT is about talking to a database from Python. Pattern is always: connect → cursor → execute → fetch or commit → close.
- For SELECT: use ? placeholders (or the driver’s params). Never build SQL with + user text — that is injection. sqlite3 is in the stdlib for practice; MySQL/Mongo need a driver.
- SELECT on the board: insert Asha, select her back, print the name. Same idea on MySQL. Close the connection.
- SELECT — output: [('Asha',)]. fetchall reads rows.
Technical Interview Tip: Steps in order: connect → execute → fetch/commit → close. Mention placeholders.
Code Examples for SELECT
Example
# SELECT
import sqlite3
con = sqlite3.connect(":memory:")
cur = con.cursor()
cur.execute("create table t(name text)")
cur.execute("insert into t values('Asha')")
print(cur.execute("select name from t").fetchall())
con.close()
SELECT — output: [('Asha',)]. fetchall reads rows.
How to Explain SELECT to an Interviewer
Explain SELECT as if you are teaching a junior — definition, then one tiny script.
SELECT uses connect + cursor + SQL/API. SELECT — parameterized queries. Never + user text into SQL.
What does the example print, and why?
SELECT — output: [('Asha',)]
What mistake do freshers make with SELECT?
SELECT — commit after write. close when done.