SQL Select table1.columa as table1.columb

Question

I am working on a database join and I want to do the following:

Select tabel_one.id, 
       tabel_one.title, 
       tabel_one.content, 
       table_two.value as table_two.key 
  from tabel_one 
  Join table_two ON table_two.id = table_one.id ....

The Important part is:

table_two.value as table_two.key

Is there a way this could work?

Answer 1

No, you cannot define an alias referencing a table.

In general, you should simply use:

table_two.value as key

Otherwise, as OMG Ponies suggested in another answer, you can wrap the alias in backticks:

table_two.value as `table_two.key`

Answer 2

This:

Select tabel_one.id, 
       tabel_one.title, 
       tabel_one.content, 
       table_two.value as `table_two.key` 
  from tabel_one 
  Join table_two ON table_two.id = table_one.id

...works for me on MySQL 5.1.35. Because of the period, you need to enclose the alias with backticks

Answer 3

Judging by your comment on this answer, I expect what you really want is:

Select tabel_one.id,  
       tabel_one.title,  
       tabel_one.content,  
       table_two.value as tags,
       table_three.value as author
  from table_one  
  LEFT Join table_two ON table_two.id = table_one.id 
  AND table_two.key= 'tags'
  LEFT Join table_three ON table_three.id = table_one.id 
  AND table_three.key= 'author'