Multiple join types in one statement
Sometimes you need to join more than two tables to produce the result that you want.
If you want to return all the employees,
their department names, and the projects they are responsible for,
if any, you need to join the EMPLOYEE table, the DEPARTMENT table,
and the PROJECT table to get the information. The following example
shows the query and the results:
SELECT EMPNO, LASTNAME, DEPTNAME, PROJNO
FROM CORPDATA.EMPLOYEE INNER JOIN CORPDATA.DEPARTMENT
ON WORKDEPT = DEPTNO
LEFT OUTER JOIN CORPDATA.PROJECT
ON EMPNO = RESPEMP
WHERE LASTNAME > 'S'
| EMPNO | LASTNAME | DEPTNAME | PROJNO |
|---|---|---|---|
| 000020 | THOMPSON | PLANNING | PL2100 |
| 000060 | STERN | MANUFACTURING SYSTEMS | MA2110 |
| 000100 | SPENSER | SOFTWARE SUPPORT | OP2010 |
| 000170 | YOSHIMURA | MANUFACTURING SYSTEMS | - |
| 000180 | SCOUTTEN | MANUFACTURING SYSTEMS | - |
| 000190 | WALKER | MANUFACTURING SYSTEMS | - |
| 000250 | SMITH | ADMINISTRATION SYSTEMS | AD3112 |
| 000280 | SCHNEIDER | OPERATIONS | - |
| 000300 | SMITH | OPERATIONS | - |
| 000310 | SETRIGHT | OPERATIONS | - |