案例讨论：Oracle两表连接

Oracle的两表连接怎么实现,原来是SQL的现在想换成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里该怎么办呢?讨论一: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/说明:只是不知道你没有限定哪个表的那些字段是不是只有一个表里面有，假如不是，会报错的。点评:有错误:1.oracle里两表连接不是用INNER JOIN AREACODE ON 而是用外连接LEFT OUTER JOIN .. ON或内连接LEFT in JOIN .. ON2.oracle里没有LEFT函数,取字接数是用length;讨论二: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点评:两表连接那错了，但这地方: substring(PHONEDATA.ANI,1,length(AREACODE.AREA_CODE)) = AREACODE.AREA_CODE是对的;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说明:inner join 直接相等就可以了，left换成substr。