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 totlekeeptime 　　oracle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 NULL 　　AND USERID LIKE '001136%' 　　GROUP BY AREACODE.AREA_NAME 　　ORDER 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 .. ON 　　2.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 ,AREACODE 　　where substring(PHONEDATA.ANI,1,length(AREACODE.AREA_CODE)) = AREACODE.AREA_CODE 　　and 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 NULL 　　AND USERID LIKE '001136%' 　　GROUP BY AREACODE.AREA_NAME 　　ORDER 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_name 　　FROM phonedata ,areacode 　　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' 　　/*and LEFT(phonedata.ani, length(areacode.area_code)) = areacode.area_code */ 　　and substr(phonedata.ani, 1,length(areacode.area_code)) = areacode.area_code 　　GROUP BY areacode.area_name order by totlekeeptime 　　说明:inner join 直接相等就可以了，left换成substr。