Random sample of rows

[Geog]

Hello,

I'd like to know if it is possible to make a random sample of a number/percentage of rows with the same value, i.e. to select randomly 6000 registers of field "x" where x=0

Thank you

[rski]

You can get a random sample, but I'm not sure if it is possible to set the size of a sample with one query.

select * from table where x=1 and random()<0.5;

[Atli]

Hi.

You can do this by using the random() function with the ORDER BY clause, and by adding a LIMIT clause.

For example:
[code=sql]
SELECT * FROM testTable
WHERE value = 'SomeValue'
ORDER BY random()
LIMIT 10;[/code]