联接2个表

SELECT Testcases.Testcase, Tests.Result
FROM Testcases LEFT JOIN Tests ON Tests.TestCaseID=Testcases.ID
WHERE Tests.Release=\"1.1.111\";

Tests.TestCaseID=Testcases.ID

Testcases table
---------------
ID Testcase
1  TC-1
2  TC-5
3  TC-8

Tests table
-----------
ID TestCaseID Result Release
1  1          OK     1.1.111
2  3          FAIL   1.1.111

Testcase Result
TC-1     OK
TC-5     <empty>
TC-8     FAIL

SELECT tc.Testcase, t.Result
FROM Testcases as tc, 
LEFT OUTER JOIN Tests as t 
ON Tests.TestCaseID=Testcases.ID
WHERE Tests.Release=\"1.1.111\";

SELECT Testcases.Testcase, Tests.Result
FROM Testcases LEFT OUTER JOIN Tests ON Tests.TestCaseID=Testcases.ID 
WHERE Tests.Release=\"1.1.111\"