Python Tutorials · Python MySQL

MySQL Where

Learn all about MySQL Where in this comprehensive tutorial.

5 min read advanced

MySQL Select

MySQL Order By

•When selecting records from a table, you can filter the selection by using the "WHERE" statement:
•You can also select the records that starts, includes, or ends with a given letter or phrase.
•When query values are provided by the user, you should escape the values.

Select With a Filter

When selecting records from a table, you can filter the selection by using the "WHERE" statement:

python

import mysql.connectormydb = mysql.connector.connect(  host="localhost", 
  user="yourusername",  password="yourpassword",  database="mydatabase")mycursor = 
  mydb.cursor()sql = "SELECT * FROM customers WHERE address ='Park Lane 
  38'"mycursor.execute(sql)
  myresult = mycursor.fetchall()for val_1 in myresult:  print(val_1)

Wildcard Characters

You can also select the records that starts, includes, or ends with a given letter or phrase.

Use the % to represent wildcard characters:

python

import mysql.connectormydb = mysql.connector.connect(  host="localhost", 
  user="yourusername",  password="yourpassword",  database="mydatabase")
mycursor = mydb.cursor()sql = "SELECT * FROM customers WHERE address 
  LIKE '%way%'"mycursor.execute(sql)myresult = mycursor.fetchall()for val_1 in myresult:  
  print(val_1)

Prevent SQL Injection

When query values are provided by the user, you should escape the values.

This is to prevent SQL injections, which is a common web hacking technique to destroy or misuse your database.

The mysql.connector module has methods to escape query values:

python

import mysql.connectormydb = mysql.connector.connect(  host="localhost", 
  user="yourusername",  password="yourpassword",  database="mydatabase")
mycursor = mydb.cursor()sql = "SELECT * FROM customers WHERE 
  address = %s"adr = ("Yellow Garden 2", )
  mycursor.execute(sql, adr)myresult = mycursor.fetchall()for val_1 in myresult:  
  print(val_1)

Module quiz

2 questions

Which of the following is true about MySQL Where?

It is strictly typedIt is evaluated at runtimeIt requires explicit memory managementIt is deprecated

What is the most common pitfall when working with MySQL Where?

SyntaxErrorIndentationErrorNameErrorTypeError

Answer all questions to submit.

MySQL Select

MySQL Order By

MySQL Where

AI Summary

Select With a Filter

Wildcard Characters

Prevent SQL Injection

Module quiz