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I was wondering if someone could give me an example of a SQL Sub query with a table schema and a reason for doing it.

I saw this at my previous company SELECT ( Select * from ) ...something like that. I have never used sub queries before and I'm wondering what purpose they serve .. I have no idea what the previous programmer who wrote the sub query was trying to do but I know that you can write sub queries. I just have no idea why .

Any example would be appreciated.

walterhevedeich 1-Aug-11 19:26pm
Nice link.
[no name] 2-Aug-11 10:42am
thatraja 2-Aug-11 10:44am
You welcome
[no name] 2-Aug-11 10:42am
If You want a column or a value or a single where condition data then you can use sql sub query instead of writing complex join etc.

Ex 1. Select name,gender,(Select top 1 schoolname from abc where xyzid = 1) from xyz where id=1

Ex 2. Select name,gender from xyz where id=(select max(id) from xyz)

Ex 3. Select abcxyz.Name from (select id,Name from xyz
where id=(select max(id) from xyz) ) abcxyz;

You can learn from [^here]

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