Question

我有以下疑问：

查询1：

Select * from T10,T11,T12,T13,T14 
where T10.C0 = T11.C0 and T11.C1 = T12.C0 
and T12.C1 = T13.C0 and T13.C1 = T14.C0;

查询2：

Select * from T20,T21,T22,T23,T24 
where T20.C0 = T21.C0 and T21.C1 = T22.C0 
and T22.C1 = T23.C0 and T23.C1 = T24.C0;

如何组合这两个查询来显示这些表的所有值？我想要加入T10.C1 = T20.C1。

尝试union时，我收到一条关于没有相同列数的警告，这是真的，这些表格不一样

联合

Select * from 
"ProductConfig","Board","PcbBuild","Model","TcssCalib" 
where "Model"."idModel" = "PcbBuild"."Model" and "Board"."PcbBuild" = "PcbBuild"."idPcbBuild" 
and "Board"."idBoard" = "TcssCalib"."Board" and "ProductConfig"."TcssCalib" = "TcssCalib"."idTcssCalib"

union

Select * from"ProductBuild","TxResultsLink","TxResults","DspValues" where "ProductBuild"."idProductBuild"
 = "TxResultsLink"."ProductBuild" and "TxResults"."idTxResults" = "TxResultsLink"."TxResults" 
and "TxResults"."DspValues" = "DspValues"."idDspValues";

这里我希望ProductBuild.Productconfig与ProductConfig.idProductConfig一起

给出错误：

[Err]错误：每个UNION查询必须具有相同的列数

当我尝试inner join时，我在inner

附近收到语法错误

有没有办法将这两个查询连接在一起？

Answer 1

这就是你想要的：

Select * from T10,T11,T12,T13,T14,T20,T21,T22,T23,T24
where T10.C0 = T11.C0 and T11.C1 = T12.C0 
and T12.C1 = T13.C0 and T13.C1 = T14.C0
and T10.C1 = T20.C1 and T20.C0 = T21.C0 and T21.C1 = T22.C0 
and T22.C1 = T23.C0 and T23.C1 = T24.C0;

另一种更易读的方式就是这样：

select * from T10
  inner join T11 on T10.C0 = T11.C0
  inner join T12 on T11.C1 = T12.C0 
  inner join T13 on T12.C1 = T13.C0 
  inner join T14 on T13.C1 = T14.C0
  inner join T20 on T10.C1 = T20.C1
  inner join T21 on T20.C0 = T21.C0
  inner join T22 on T21.C1 = T22.C0 
  inner join T23 on T22.C1 = T23.C0
  inner join T24 on T23.C1 = T24.C0;

要使UNION结果，表中的列数必须相同且来自相同/可转换的数据类型。

Select * from T10,T11,T12,T13,T14 
where T10.C0 = T11.C0 and T11.C1 = T12.C0 
and T12.C1 = T13.C0 and T13.C1 = T14.C0

UNION

Select * from T20,T21,T22,T23,T24 
where T20.C0 = T21.C0 and T21.C1 = T22.C0 
and T22.C1 = T23.C0 and T23.C1 = T24.C0;

Select * from 
"ProductConfig","Board","PcbBuild","Model","TcssCalib","ProductBuild","TxResultsLink","TxResults","DspValues"
where "Model"."idModel" = "PcbBuild"."Model" and "Board"."PcbBuild" = "PcbBuild"."idPcbBuild" 
and "Board"."idBoard" = "TcssCalib"."Board" and "ProductConfig"."TcssCalib" = "TcssCalib"."idTcssCalib" and "ProductBuild"."idProductBuild"
 = "TxResultsLink"."ProductBuild" and "TxResults"."idTxResults" = "TxResultsLink"."TxResults" 
and "TxResults"."DspValues" = "DspValues"."idDspValues"
and "ProductBuild"."ProductConfig" = "ProductConfig"."idProductConfig";

结合两个查询 - 如何？

1 个答案: