Are there alternatives to UNION for selecting the same columns from multiple tables?
I've got 4-5 tables that have near identical names and I need to select columns which have the same names from them. So far I'm doing this:
SELECT colA, colB FROM Table1
UNION
SELECT colA, colB FROM Table2
UNION
etc...
It seems like it could be overly verbose if you had more than a handful of similar tables and was wondering if there's any alternative syntax. Ideally I'd like something wildcard-y, like
SELECT colA, colB FROM Table%
If there is no al开发者_运维知识库ternative to UNION
, why not? Is there a specific reason for not allowing this? I would imagine it's because SQL should be as specific as possible when it comes to the table definitions (table + col names, types, etc) while allowing flexibility in data manipulation (hence we have wildcards for the rows).
There's no alternative I could think of. If I were nitpicky, I'd say that if you have similar tables that contain similar data, you should reconsider your database design :-)
No alternate for the UNION query developed by the database provider.
you can use table aliases. for instance:
select a.colA, b.colA, a.colB, b.colB
from table1 a
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