MySql Query Optimisation

Question

I have 3 tables, I need advice on how to get data from them.

Table name

details_varchar  

details_int  

details_date

each of them have value_id[Int] and value_name [value_name type varies as per table name - Varchar, Int, Date]

Conditions

only one unique value_id will be present in any one of the 3 tables. i.e ID from 1 to n are stored in these tables according to their Data Types. If value_id = 1 and value_name[type] = int then it stores in details_int table.

What I need

select value_name from 3 tables[may appear in any one of the table] where value_id = '[I have this value stored in a variable]'

What I tried

UNION - but all the table needs to have same column type.

JOINS - All the fields should be connected.[I guess]

Robin Castlin · Accepted Answer · 2012-03-27 10:41:40Z

1

SELECT value_name
FROM (  SELECT value_name
        FROM details_varchar
        WHERE value_id = {$int_value_id}
        UNION ALL
        SELECT value_name
        FROM details_int
        WHERE value_id = {$int_value_id}
        UNION ALL
        SELECT value_name
        FROM details_date
        WHERE value_id = {$int_value_id}) AS h

This should give you what you want?

answered Mar 27, 2012 at 10:41

Robin Castlin

11k1 gold badge30 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

MySql Query Optimisation

Table name

Conditions

What I need

What I tried

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

Table name

Conditions

What I need

What I tried

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related