module Gitlab module Database module DateTime # Find the first of the `end_time_attrs` that isn't `NULL`. Subtract from it # the first of the `start_time_attrs` that isn't NULL. `SELECT` the resulting interval # along with an alias specified by the `as` parameter. # # Note: For MySQL, the interval is returned in seconds. # For PostgreSQL, the interval is returned as an INTERVAL type. def subtract_datetimes(query_so_far, end_time_attrs, start_time_attrs, as) diff_fn = if Gitlab::Database.postgresql? Arel::Nodes::Subtraction.new( Arel::Nodes::NamedFunction.new("COALESCE", Array.wrap(end_time_attrs)), Arel::Nodes::NamedFunction.new("COALESCE", Array.wrap(start_time_attrs))) elsif Gitlab::Database.mysql? Arel::Nodes::NamedFunction.new( "TIMESTAMPDIFF", [Arel.sql('second'), Arel::Nodes::NamedFunction.new("COALESCE", Array.wrap(start_time_attrs)), Arel::Nodes::NamedFunction.new("COALESCE", Array.wrap(end_time_attrs))]) end query_so_far.project(diff_fn.as(as)) end end end end