inner join and 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: inner join
INNER JOIN is used when retrieving data from
multiple tables and will return only matching data.
example=
Select P.FIRST_NAME , M.DRUG_ID
FROM PATIENTS P
INNER JOIN MEDICATIONS M ON P.PATIENTS_ID = M.PATIENTS_ID