选择右列 [英] Selecting the right column

问题描述

我有一个查询.

with result as
(
select t1.name, t1.number, t2.number from table1 t1, table2 t2 where some conditions
union all
select t1.name, t1.number, t3.number from table1 t1, table3 t3 where some conditions
)select * from result

我需要在表5中插入t1.name和t2.number

I need to insert in table5 t1.name and t2.number

table5与t1的列相同.

table5 has the same columns as t1.

如果我做类似

insert in table5(name, number)
select r.name, r.number from result r

什么是r.number? t1.number或t2.number?因为列具有相同的名称.还是有办法区分?我怎样才能使查询跳过带有t3.number的每一行?我什至可以做到吗?

what would be considered r.number? t1.number or t2.number? Because columns have the same name. Or is there a way to defferentiate? How can I make it so the query skips every row with t3.number? Can I even do it?

例如，我有table1

For example I have table1

A ([phone]
B ([phone]
C ([phone]

table2

([phone]
([phone]

首先选择会得到我

A ([phone] ([phone]
B ([phone] ([phone]

table3

([phone]
([phone]
([phone]

第二选择的结果

B ([phone] ([phone]
C ([phone] ([phone]

这将是全部并集的结果

A ([phone] ([phone]
B ([phone] ([phone]
B ([phone] ([phone]
C ([phone] ([phone]

我到底想要什么

A ([phone]
B ([phone]

最终结果不应包含该行

B ([phone] ([phone]
C ([phone] ([phone]

推荐答案

两者.在某些行中，t2.number是number，在另一些行中，t3.number是number.

Both. In some rows, t2.number is number and in others t3.number is number.

union all的结果在单个结果集中.结果集不知道任何特定列中值的来源(尽管您可以在此列中包含此信息).

The result of the union all in a single result set. The result set doesn't know the origin of the values in any particular column (although you could include another column with this information).

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