SQL JOIN allows us to fetch records on other table based on the given conditions between two tables.
For example,if we have the Employee ID of each employee, then we can use this Employee ID of the employee table to join with the Employee ID of Project master table to fetch employe details.
UNION operation allows us to add 2 similar data sets to create resulting data set that contains all the data from the source data sets.Union does not require any condition for joining.
For example, if you have 2 employee tables with same structure, you can UNION them to create one result set that will contain all the records from both of the tables.
Suppose we have 2 tables i.e. Employee_Master and Project_Master.
Select emp.employee_name,emp.address,emp.ph_no from employee_master emp
on emp.employee_id = prj.emp_id and prj.status = 'AA'
where emp.status = 'AA';
Select * from table_name1
Select * from table_name2
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