MySQL Where

Select With a Filter

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

Example

import mysql.connector

mydb = 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 x in myresult:
  print(x)

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:

Example

import mysql.connector

mydb = 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 x in myresult:

print(x)

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:

Example

import mysql.connector

mydb = 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 x in myresult:

print(x)