SQL 
  
  ˵Ʊ(ֻƽṹ,Դa ±b) 
  
  SQL: select * into b from a where 1<>1 
  
  ˵(,Դa Ŀb) 
  
  SQL: insert into b(a, b, c) select d,e,f from b; 
  
  ˵ʾ¡ύ˺ظʱ 
  
  SQL: select a.title,a.username,b.adddate from table a,(select max(adddate) adddate from table where table.title=a.title) b 
  
  ˵Ӳѯ(1a 2b) 
  
  SQL: select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c 
  
  ˵ճ̰ǰ 
  
  SQL: select * from ճ̰ where datediff('minute',fʼʱ,getdate())>5 
  
  ˵ŹɾѾڸûеϢ 
  
  SQL: 
  
  delete from info where not exists ( select * from infobz where info.infid=infobz.infid ) 
  
  ˵-- 
  
  SQL: 
  
  SELECT A.NUM, A.NAME, B.UPD_DATE, B.PREV_UPD_DATE 
  
  FROM TABLE1, 
  
  (SELECT X.NUM, X.UPD_DATE, Y.UPD_DATE PREV_UPD_DATE 
  
  FROM (SELECT NUM, UPD_DATE, INBOUND_QTY, STOCK_ONHAND 
  
  FROM TABLE2 
  
  WHERE TO_CHAR(UPD_DATE,'YYYY/MM') = TO_CHAR(SYSDATE, 'YYYY/MM')) X, 
  
  (SELECT NUM, UPD_DATE, STOCK_ONHAND 
  
  FROM TABLE2 
  
  WHERE TO_CHAR(UPD_DATE,'YYYY/MM') = 
  
  TO_CHAR(TO_DATE(TO_CHAR(SYSDATE, 'YYYY/MM') || '/01','YYYY/MM/DD') - 1, 'YYYY/MM') ) Y, 
  
  WHERE X.NUM = Y.NUM + 
  
  AND X.INBOUND_QTY + NVL(Y.STOCK_ONHAND,0) <> X.STOCK_ONHAND ) B 
  
  WHERE A.NUM = B.NUM 
  
  ˵-- 
  
  SQL: 
  
  select * from studentinfo where not exists(select * from student where studentinfo.id=student.id) and ϵ='"&strdepartmentname&"' and רҵ='"&strprofessionname&"' order by Ա,Դ,߿ܳɼ 
  
  ˵ 
  
  ݿȥһĸλ绰ͳ(绰Ѷص绯嵥Դ 
  
  SQL: 
  
  SELECT a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') AS telyear, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '01', a.factration)) AS JAN, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '02', a.factration)) AS FRI, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '03', a.factration)) AS MAR, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '04', a.factration)) AS APR, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '05', a.factration)) AS MAY, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '06', a.factration)) AS JUE, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '07', a.factration)) AS JUL, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '08', a.factration)) AS AGU, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '09', a.factration)) AS SEP, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '10', a.factration)) AS OCT, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '11', a.factration)) AS NOV, 
  
  SUM(decode(TO_CHAR(a.telfeedate, 'mm'), '12', a.factration)) AS DEC 
  
  FROM (SELECT a.userper, a.tel, a.standfee, b.telfeedate, b.factration 
  
  FROM TELFEESTAND a, TELFEE b 
  
  WHERE a.tel = b.telfax) a 
  
  GROUP BY a.userper, a.tel, a.standfee, TO_CHAR(a.telfeedate, 'yyyy') 
  
  ˵ı⣺ 
  
  SQL: select * from a left inner join b on a.a=b.b right inner join c on a.a=c.c inner join d on a.a=d.d where ..... 
  
  ˵õСδʹõID 
  
  SQL: 
  
  SELECT (CASE WHEN EXISTS(SELECT * FROM Handle b WHERE b.HandleID = 1) THEN MIN(HandleID) + 1 ELSE 1 END) as HandleID 
  
  FROM Handle 
  
  WHERE NOT HandleID IN (SELECT a.HandleID - 1 FROM Handle a)