HOW TO USE JOIN AND WHERE in sql code example
Example 1: how to join tables in sql
JOINING 2 Tables in sql
SELECT X.Column_Name , Y.Column_Name2
FROM TABLES1_NAME X
INNER JOIN TABLES2_NAME Y ON X.Primary_key = Y.Foreign_key;
--FOR EXAMPLE
--GET THE FIRST_NAME AND JOB_TITLE
--USE EMPLOYEES AND JOBS TABLE
--THE RELATIONSHIP IS JOB_ID
SELECT E.FIRST_NAME , J.JOB_TITLE
FROM EMPLOYEES E
INNER JOIN JOBS J ON J.JOB_ID = E.JOB_ID;
Example 2: use where instead of join
# using WHERE ANSI-89 syntax
SELECT *
FROM TABLE_A a,
TABLE_B b
WHERE a.id = b.id
# using JOIN ANSI-92 syntax
SELECT *
FROM TABLE_A a
JOIN TABLE_B b ON b.id = a.id