Question

sql语句在一个oracle数据库里面查询。只有多个表里都有一项数据才能查询到。但是我想一个有就能查询

select balance.maintainNum,balance.maintainPrice,balance.partsPrice,balance.balanceTime,balance.printTime,cusInfo.cusCompName,cusInfo.cusContact,warranty.ProductType,warranty.machineName,warranty.machineType,warranty.serialNum,warranty.machFauPhen,warranty.warrantyTime,repair.maCheckRec,outstore.spPartsName,outstore.spPartsType,outstore.spPartsNum,outstore.spPartsUnit from cusInfo,warranty,repair,balance,outstore where cusInfo.cusId=warranty.cusId and balance.maintainNum=repair.maintainNum and balance.maintainNum=balance.maintainNum and balance.maintainNum=outstore.maintainNum and balance.maintainNum=?
想balance有数据就可以显示

Answer 1

使用 外连接 即可

Answer 2

(balance.maintainNum=balance.maintainNum)
你的sql这里错了，

例子：select a.id,b.name,c.name from a_test a,b_test b,c_test c where a.id=b.id(+) and b.id=c.id(+);
a_test的id有数据，b和c 没有数据的情况下也显示，不过除了a.id其他都是null。

Answer 3

的萨芬撒的份上打分