Proper use of the where method om ActiveRecord.

rubyonrails-talk
1

I am trying to determine what is going on with the following code:

In AR def self.all_billables where( :is_billed => false ) end

returns 2 records.

def self.all_billables where( “is_billed” => false ) end

also returns 2 records.

In sqlite3

select * from tests where ( “is_billed” = ‘false’ );

returns 2 records.

However, if I use these forms in AR then I get nothing returned:

def self.all_billables where( %Q( “is_billed” = ‘false’ ) ) end

def self.all_billables

where( “is_billed = ‘false’” )

end

What am I missing here?

2

Look in log/development.log to see what the difference is in the queries (which should be logged there). Then it will probably make sense.

Colin

3

This is the difference:

(0.2ms) SELECT COUNT() FROM “tests” WHERE (is_billed = ‘false’) vice (0.2ms) SELECT COUNT() FROM “tests” WHERE (is_billed = ‘f’)

The second form is generated from the ( :is_billed => false ) construction. If I cut and paste “is_billed = ‘f’” into the where clause then it works. I presume this is some sort of implementation issue with sqlite3.

4

By using :is_billed => false you are telling rails that you want the value to be whatever rails uses as the logical value false (which appears to be "f"). By specifying yourself that the contents of the column must be the string "false" it does not find the records.

I am a bit surprised that the sqlite example you gave works. Are you sure you entered the query exactly as you showed? I am not that familiar with sqlite however.

Colin

5

It appears that sqlite3 does not have a concept of a boolean type. I find that you can put literally any string into a boolean column in an sqlite3 database. As I was testing in sqlite with data rows I had inserted having is_billed values ( ‘false’ ) selecting where ( “is_billed” = ‘false’ ) naturally worked. Ah well, live and learn.