Select « Select Clause « SQL / MySQL

1.Define and use variable in select clause
2.Use defined variable in new select clause
3.Select clause with condition
4.Choose specific columns
5.Reference column in select command
6.Performing Mathematics
7.Simple Retrieval:Returning Multiple Columns
8.Simple Retrieval:Returning a Single Column
9.Simple Retrieval: Returning All Columns

10.Performing a Single Row INSERT
11.Retrieve all columns in a table
12.Using constant string value as comment message for aggregate function