If you want to fetch, delete or, update particular rows of a table in SQLite, you need to use the where clause to specify condition to filter the rows of the table for the operation.

For example, if you have a SELECT statement with where clause, only the rows which satisfies the specified condition will be retrieved.

Syntax

Following is the syntax of the WHERE clause in SQLite −

SELECT column1, column2, columnN
FROM table_name
WHERE [search_condition]

You can specify a search_condition using comparison or logical operators. like >, <, =, LIKE, NOT, etc. The following examples would make this concept clear.

Example

Assume we have created a table with name CRICKETERS using the following query −

sqlite> CREATE TABLE CRICKETERS (
   First_Name VARCHAR(255),
   Last_Name VARCHAR(255),
   Age int,
   Place_Of_Birth VARCHAR(255),
   Country VARCHAR(255)
);
sqlite>

And if we have inserted 5 records in to it using INSERT statements as −

sqlite> insert into CRICKETERS values(''Shikhar'', ''Dhawan'', 33, ''Delhi'', ''India'');
sqlite> insert into CRICKETERS values(''Jonathan'', ''Trott'', 38, ''CapeTown'', ''SouthAfrica'');
sqlite> insert into CRICKETERS values(''Kumara'', ''Sangakkara'', 41, ''Matale'', ''Srilanka'');
sqlite> insert into CRICKETERS values(''Virat'', ''Kohli'', 30, ''Delhi'', ''India'');
sqlite> insert into CRICKETERS values(''Rohit'', ''Sharma'', 32, ''Nagpur'', ''India'');
sqlite>

Following SELECT statement retrieves the records whose age is greater than 35 −

sqlite> SELECT * FROM CRICKETERS WHERE AGE > 35;
First_Name Last_Name  Age  Place_Of_B Country
---------- ---------- ---- ---------- -------------
Jonathan   Trott      38   CapeTown   SouthAfrica
Kumara     Sangakkara 41   Matale     Srilanka
sqlite>

Where clause using python

The Cursor object/class contains all the methods to execute queries and fetch data, etc. The cursor method of the connection class returns a cursor object.

Therefore, to create a table in SQLite database using python −

• Establish connection with a database using the connect() method.

• Create a cursor object by invoking the cursor() method on the above created connection object.

• Now execute the CREATE TABLE statement using the execute() method of the Cursor class.

Example

Following example creates a table named Employee and populates it. Then using the where clause it retrieves the records with age value less than 23.

import sqlite3

#Connecting to sqlite
conn = sqlite3.connect(''example.db'')

#Creating a cursor object using the cursor() method
cursor = conn.cursor()

#Doping EMPLOYEE table if already exists.
cursor.execute("DROP TABLE IF EXISTS EMPLOYEE")
sql = ''''''CREATE TABLE EMPLOYEE(
   FIRST_NAME CHAR(20) NOT NULL,
   LAST_NAME CHAR(20),
   AGE INT,
   SEX CHAR(1),
   INCOME FLOAT
)''''''
cursor.execute(sql)

#Populating the table
cursor.execute(''''''INSERT INTO EMPLOYEE(
   FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) VALUES 
   (''Ramya'', ''Rama priya'', 27, ''F'', 9000)'''''')

cursor.execute(''''''INSERT INTO EMPLOYEE
   (FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) VALUES 
   (''Vinay'', ''Battacharya'', 20, ''M'', 6000)'''''')

cursor.execute(''''''INSERT INTO EMPLOYEE(
   FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) VALUES 
   (''Sharukh'', ''Sheik'', 25, ''M'', 8300)'''''')

cursor.execute(''''''INSERT INTO EMPLOYEE(
   FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) VALUES 
   (''Sarmista'', ''Sharma'', 26, ''F'', 10000)'''''')

cursor.execute(''''''INSERT INTO EMPLOYEE(
   FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) VALUES 
   (''Tripthi'', ''Mishra'', 24, ''F'', 6000)'''''')

#Retrieving specific records using the where clause
cursor.execute("SELECT * from EMPLOYEE WHERE AGE <23")
print(cursor.fetchall())

#Commit your changes in the database
conn.commit()

#Closing the connection
conn.close()

Output

[(''Vinay'', ''Battacharya'', 20, ''M'', 6000.0)]