案例討論：Oracle兩表連接

Oracle的兩表連接怎么實現,原來是SQL的現在想換成oracle的，SQL的如下: SELECT COUNT(*) AS COUNT, SUM(timelen) AS totlekeeptime, SUM(moneys) AS totletimefee, SUM(realmoneys) AS totlenewfee, areacode.area_name FROM phonedata INNER JOIN areacode ON LEFT(phonedata.ani, LEN(areacode.area_code)) = areacode.area_code WHERE starttime>'2005-12-27 00:00:00' and starttime<'2005-12-27 23:59:59' and endtime is not null and userid like '001136' GROUP BY areacode.area_name order by totlekeeptimeoracle里該怎么辦呢?討論一:SELECT AREACODE.AREA_NAME,COUNT(*) AS COUNT,SUM(TIMELEN) AS TOTLEKEEPTIME,SUM(MONEYS) AS TOTLETIMEFEE,SUM(REALMONEYS) AS TOTLENEWFEE,FROM PHONEDATA INNER JOIN AREACODE ON (LEFT(PHONEDATA.ANI,LEN(AREACODE.AREA_CODE)) = AREACODE.AREA_CODE)WHERE STARTTIME>'2005-12-27 00:00:00'AND STARTTIME<'2005-12-27 23:59:59'AND ENDTIME IS NOT NULLAND USERID LIKE '001136%'GROUP BY AREACODE.AREA_NAMEORDER BY TOTLEKEEPTIME/說明:只是不知道你沒有限定哪個表的那些字段是不是只有一個表里面有，假如不是，會報錯的。點評:有錯誤:1.oracle里兩表連接不是用INNER JOIN AREACODE ON 而是用外連接LEFT OUTER JOIN .. ON或內連接LEFT in JOIN .. ON2.oracle里沒有LEFT函數,取字接數是用length;討論二:SELECT AREACODE.AREA_NAME,COUNT(*) AS COUNT,SUM(TIMELEN) AS TOTLEKEEPTIME,SUM(MONEYS) AS TOTLETIMEFEE,SUM(REALMONEYS) AS TOTLENEWFEE,FROM PHONEDATA ,AREACODEwhere substring(PHONEDATA.ANI,1,length(AREACODE.AREA_CODE)) = AREACODE.AREA_CODEand to_date(STARTTIME,'yyyy-mm-dd hr24:mi:ss')>'2005-12-27 00:00:00'AND to_date(STARTTIME,'yyyy-mm-dd hr24:mi:ss')<'2005-12-27 23:59:59'AND ENDTIME IS NOT NULLAND USERID LIKE '001136%'GROUP BY AREACODE.AREA_NAMEORDER BY TOTLEKEEPTIME點評:兩表連接那錯了，但這地方: substring(PHONEDATA.ANI,1,length(AREACODE.AREA_CODE)) = AREACODE.AREA_CODE是對的;最佳答案:SELECT COUNT(*) AS COUNT, SUM(timelen) AS totlekeeptime, SUM(moneys) AS totletimefee,SUM(realmoneys) AS totlenewfee, areacode.area_nameFROM phonedata ,areacodeWHERE starttime>'2005-12-27 00:00:00' and starttime<'2005-12-27 23:59:59'and endtime is not null and userid like '001136'/*and LEFT(phonedata.ani, length(areacode.area_code)) = areacode.area_code */and substr(phonedata.ani, 1,length(areacode.area_code)) = areacode.area_codeGROUP BY areacode.area_name order by totlekeeptime說明:inner join 直接相等就可以了，left換成substr。