When you insert or update your table using data from other tables, you will often need to rectify values that use different datatypes. These tables are shown below:

WSS also maintains a separate table that tracks raises by department, in order to make sure that some departments aren’t favored over others. Each time a member of any department receives a raise, the employees last name and department code are retrieved from the Employee table and inserted into the DepartmentRaise table.

Before proceeding to write an INSERT statement, there is a new snag that must be dealt with. The DepartmentCode column in the Employee table is a char(3) datatype, while the DepartmentCode column in the DepartmentRaise table is an int datatype.
When inserting data, the datatype of the inserted data must always be compatible with the datatype of the column that is being retrieved.

When the datatypes are not compatible, you can convert the data with the CAST SQL Server function. The CAST function follows this syntax:
NINAH: new image goes here: castfunction.gif
With this in mind, the following statement will retrieve Mickey’s last name and department code from the Employee table and insert this data into the DepartmentRaise table:

INSERT INTO DepartmentRaise(LastName, DepartmentCode)  
SELECT LastName, CAST(DepartmentCode AS char(3))
FROM Employee
WHERE LastName = ‘Mouse’
AND FirstName = ‘Micky’

As a result of the commands issued above, the DepartmentRaise table will now look like this: