UNION Examples | SQL Statements | Teradata Vantage - 17.05 - Example: Selecting the Name, Project, and Employee Hours - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL Data Manipulation Language

Advanced SQL Engine
Teradata Database
Release Number
Release Date
January 2021
Content Type
Programming Reference
Publication ID
English (United States)

To select the name, project, and the number of hours spent by employees assigned to project OE1-0001, plus the names of employees not assigned to a project, the following query could be used:

   SELECT Name, Proj_Id, Hours
   FROM Employee,Charges 
   WHERE Employee.Empno = Charges.Empno 
   AND Proj_Id IN ('OE1-0001')
   SELECT Name, NULL (CHAR (8)), NULL (DECIMAL (4,2)) 
   FROM Employee 
   (SELECT Empno 
   FROM Charges);

This query returns the following rows.

Name Project Id Hours
Aguilar J ? ?
Brandle B ? ?
Chin M ?  
Clements D ? ?
Kemper R    
Marston A ? ?
Phan A ? ?
Regan R ? ?
Russell S ? ?
Smith T    
Watson L    
Inglis C 0E1-0001 30.0
Inglis C 0E1-001 30.5
Leidner P 0E1-001 10.5
Leidner P 0E1-001 23.0
Moffit H 0E1-001 12.0
Moffit H 0E1-001 35.5

In this example, null expressions are used in columns 2 and 3 of the second SELECT statement. The null expressions are used as place markers so that both SELECT statements in the query contain the same number of expressions.