The concept of temporary SQL TEMP TABLE is introduced by SQL server. It helps developers in many ways:
Temporary tables( SQL TEMP TABLE )can be created at run-time and can do all kinds of operations that a normal table can do. These temporary tables are created inside tempdb database.
There are two types of temp tables based on the behavior and scope.
- Local Temp Variable
- Global Temp Variable
Local Temp Variable
Local temp tables are only available at current connection time. It is automatically deleted when user disconnects from instances. It is started with hash (#) sign.
CREATE TABLE #local temp table ( User id int, Username varchar (50), User address varchar (150) )
Global Temp Variable
Global temp tables name starts with double hash (##). Once this table is created, it is like a permanent table. It is always ready for all users and not deleted until the total connection is withdrawn.
CREATE TABLE ##new global temp table ( User id int, User name varchar (50), User address varchar (150) )