DQL- SELECT - 16-06-2025

DQL- DATA QUERY LANGUAGE

SELECT

SELECT REQUIRED DETAIILS/columns

SELECT C1,C2 FROM TABLE NAME;

EX;
select name,category,gender from staff_details;

SELECT wont affect any data in the table.

RENAME (To display )- AS (alias)

SELECT C1 as "rename", from table name;

select name as "staff name",category,gender,salary from staff_details;

*WHERE- CONDITION.
*

select*from staff_details where DIVISION='CONSTRUCTION';

*BETWEEN
*

SELECT*FROM STAFF_DETAILS WHERE SALARY BETWEEN 15000 AND 30000;

*LIKE- To search from letters
*

SELECT*FROM STAFF DETAILS WHERE COLUMN LIKE 'A%'

SELECT*FROM STAFF_DETAILS WHERE NAME LIKE'A%';
OR 'A%A'
OR '%A'

*IN- LIST OF DATA.
*

SELECT*FROM STAFF_DETAILS WHERE SALARY IN (10000,20000);

SELECT*FROM STAFF_DETAILS WHERE SALARY NOT IN (10000,20000);

AGGREGATE FUNCTION

FUNCTION ()

*COUNT *:
SELECT COUNT (*FROM) STAFF_DETAILS;

SUM:

SELECT SUM (SALARY) FROM STAFF_DETAILS;

*AVERAGE:
*
SELECT AVG(SALARY) FROM STAFF_dETAILS;

*ROUND:
*

SELECT ROUND (AVG(SALARY)) FROM STAFF_DETAILS;

*ROUND ON DECIMALS:
*
SELECT ROUND (AVG(SALARY),2) FROM STAFF_DETAILS;

MIN VALUES

SELECT MIN(SALARY)FROM STAFF_DETAILS;

*SELECT ROW FROM MIN SALARY.
*
SELECT*FROM STAFF_DETAILS WHERE SALARY=(SELECT MIN(SALARY)FROM STAFF_DETAILS);