T-SQL: Comparing Two Tables - Records that don't exist in second table

Question

If UNION ALL is an addition in T-SQL. What is the equivalent of subtraction?

For example, if I have a table PEOPLE and a table

Answer 1

You can use the EXCEPT operator to subtract one set from another. Here's a sample of code using EMPLOYEES and PEOPLE temporary tables. You'll need to use the field names with the EXCEPT operator as far as I know.

CREATE TABLE #PEOPLE
(ID INTEGER,
 Name NVARCHAR(50))

CREATE TABLE #EMPLOYEE
(ID INTEGER,
 Name NVARCHAR(50))
GO

INSERT #PEOPLE VALUES (1, 'Bob')
INSERT #PEOPLE VALUES (2, 'Steve')
INSERT #PEOPLE VALUES (3, 'Jim')
INSERT #EMPLOYEE VALUES (1, 'Bob')
GO

SELECT ID, Name
FROM #PEOPLE
EXCEPT 
SELECT ID, Name
FROM #EMPLOYEE
GO

The final query will return the two rows in the PEOPLE table which do not exist in the EMPLOYEE table.