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, start_time_attrs, end_time_attrs, as)
diff_fn = subtract_datetimes_diff(query_so_far, start_time_attrs, end_time_attrs)
query_so_far.project(diff_fn.as(as))
end
def subtract_datetimes_diff(query_so_far, start_time_attrs, end_time_attrs)
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
end
end
end
end