What is the difference between UNION and UNION ALL?

Question

What is the difference between UNION and UNION ALL?

Answer 1

union is used to select distinct values from two tables where as union all is used to select all values including duplicates from the tables

Answer 2

Difference Between Union Vs Union ALL In Sql

What Is Union In SQL?

The UNION operator is used to combine the result-set of two or more data set .

Each SELECT statement within UNION must have the same number of columns
The columns must also have similar data types
The columns in each SELECT statement must also be in the same order

Union Vs Union All With Example