SQL從3個具有相同列名的表中選擇

Question

我有三個具有以下結構的表：

sequence
cli
datetime
company

該表是orders_broadband orders_lines和orders_porting

我想顯示同一結果集中所有三個表的結果。

我試過運行查詢：

SELECT orders_broadband.*, orders_lines.*, orders_porting.* from orders_broadband, orders_lines, orders_porting

但我不認為查詢正確

Answer 1

你可以這樣做：

select sequence, cli, datetime, company from orders_broadband
union all
select sequence, cli, datetime, company from orders_lines
union all
select sequence, cli, datetime, company from orders_porting

這將合並所有3個表中的數據。

通過顯式添加列名進行編輯（類似於注釋部分中提到的xQbert）

顯示表名

select sequence, cli, datetime, company, 'Tablename1' as tbl from orders_broadband where status = 'New' 
UNION ALL 
select sequence, cli, datetime, company, 'Tablename2' as tbl from orders_lines where status = 'New' 
UNION ALL 
select sequence, cli, datetime, company, 'Tablename3' as tbl from orders_porting where status = 'New'

將“ Tablename1”和其他名稱更改為您認為合適的名稱。

如果要從orders_broadband添加其他列怎么辦？

select '' as telephone_number, sequence, cli, datetime, company, 'Tablename1' as tbl from orders_broadband where status = 'New' 
UNION ALL 
select '' as telephone_number, sequence, cli, datetime, company, 'Tablename2' as tbl from orders_lines where status = 'New' 
UNION ALL 
select telephone_number, sequence, cli, datetime, company, 'Tablename3' as tbl from orders_porting where status = 'New'