DB2 常用SQL Quick Find

Join Rows

   To combine matching rows in multiple tables, use a join

 

 

SELECT nm.id ANSWER ,jb.job ID NAME JOB FROM emp_nm nm  ,emp_jb jb 10 Sanders Sales WHERE nm.id = jb.id 20 Pernal Clerk ORDER BY 1;

 

Outer Join

   To get all of the rows from one table, plus the matching rows from another table (if there are
any), use an outer join

 

SELECT nm.id ANSWER,nm.name ,jb.job ID NAME JOB FROM emp_nm nm  LEFT OUTER JOIN 10 Sanders Sales  emp_jb jb  ON nm.id = jb.id  ORDER BY nm.id;

 

 

    Fetch First "n" Rows
To fetch the first "n" matching rows, use the FETCH FIRST notation

 

SELECT * FROM EMP_MM ORDER BY ID DESC FETCH FIRST 2 ROWS ONLY