GROUP BY Clause

SQLite GROUP BY clause is used in collaboration with the SELECT statement to arrange identical data into groups.

GROUP BY clause follows the WHERE clause in a SELECT statement and precedes the ORDER BY clause.

Syntax

Following is the basic syntax of GROUP BY clause. GROUP BY clause must follow the conditions in the WHERE clause and must precede ORDER BY clause if one is used.

SELECT column-list FROM table_name WHERE [ conditions ] GROUP BY column1, column2....columnN ORDER BY column1, column2....columnN

You can use more than one column in the GROUP BY clause. Make sure whatever column you are using to group, that column should be available in the column-list.

Example

Consider COMPANY table with the following records.

ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0

If you want to know the total amount of salary on each customer, then GROUP BY query will be as follows −

sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME;

This will produce the following result −

NAME SUM(SALARY) ---------- ----------- Allen 15000.0 David 85000.0 James 10000.0 Kim 45000.0 Mark 65000.0 Paul 20000.0 Teddy 20000.0

Now, let us create three more records in COMPANY table using the following INSERT statements.

INSERT INTO COMPANY VALUES (8, 'Paul', 24, 'Houston', 20000.00 ); INSERT INTO COMPANY VALUES (9, 'James', 44, 'Norway', 5000.00 ); INSERT INTO COMPANY VALUES (10, 'James', 45, 'Texas', 5000.00 );

Now, our table has the following records with duplicate names.

ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 8 Paul 24 Houston 20000.0 9 James 44 Norway 5000.0 10 James 45 Texas 5000.0

Again, let us use the same statement to group-by all the records using NAME column as follows −sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME ORDER BY NAME;

This will produce the following result.

NAME SUM(SALARY) ---------- ----------- Allen 15000 David 85000 James 20000 Kim 45000 Mark 65000 Paul 40000 Teddy 20000

Let us use ORDER BY clause along with GROUP BY clause as follows −sqlite> SELECT NAME, SUM(SALARY) FROM COMPANY GROUP BY NAME ORDER BY NAME DESC;

This will produce the following result.

NAME SUM(SALARY) ---------- ----------- Teddy 20000 Paul 40000 Mark 65000 Kim 45000 James 20000 David 85000 Allen 15000