Raw DB querying in Rails
I'm pretty sure your NoMethodError is coming from the logging stuff. If we look exec_query
, we see this:
def exec_query(sql, name = 'SQL', binds = []) log(sql, name, binds) do # call exec_no_cache(sql, binds) or exec_cache(sql, binds)...
Then if we look at exec_cache
, we see this:
def exec_cache(sql, binds) #.. @connection.send_query_prepared(stmt_key, binds.map { |col, val| type_cast(val, col) })
so the binds
are supposed to be column/value pairs. The PostgreSQL driver expects col
to be a column object so that it can ask it what its name is and how it should format the val
, that information is used by the log
call in exec_query
to produce something pretty and human-readable in the Rails logs. A bit of experimentation suggests that you can use nil
as the col
and everything is happy.
That means that we've moved on to this:
exec_query( 'SELECT * FROM users WHERE id IN ($1)', 'my query', [ [nil, [1,2]] ])
The underlying driver may or may not know what to do with the [1,2]
array, I only have Rails3 with the PostgreSQL extensions available to test and it doesn't like the [1,2]
. If Rails4 also doesn't like the array then you can pass the arguments one-by-one:
exec_query( 'SELECT * FROM users WHERE id IN ($1, $2)', 'my query', [ [nil,1], [nil,2] ])
I ran into a similar issue lately. It turns out that in the where in (?)
, ActiveRecord is expecting a string, not an array. So you can try passing in a string of comma-separated ids and that should do the trick.