SQL DEFAULT VALUE

Question

I would like to set a default value to a variable

SELECT ID, VALUE
FROM TABLE

Now I would like that value to have a default value of 0 for every ID. What can I do?

Answer 1

Are you asking how to specify a default value in the select:

SELECT ID, 0 as VALUE FROM TABLE

Or do you want to have the underlying table column have a default value?

Answer 2

If you mean you want a default value for when the column is null then you can use the NVL function (at least in oracle), e.g.

SELECT NVL(thecol, 0) FROM thetable;

Answer 3

select id, 0 as value_default from myTable

so you have an initial default value assigned against a named column (the value of which you can change).

Answer 4

SELECT ID, IFNULL(VALUE,0) as Value
FROM MyTable

This will select ID, and Value. If value is null it will display 0