require 'helper' module Arel module Visitors describe 'the mssql visitor' do before do @visitor = MSSQL.new Table.engine.connection @table = Arel::Table.new "users" end def compile node @visitor.accept(node, Collectors::SQLString.new).value end it 'should not modify query if no offset or limit' do stmt = Nodes::SelectStatement.new sql = compile(stmt) sql.must_be_like "SELECT" end it 'should go over table PK if no .order() or .group()' do stmt = Nodes::SelectStatement.new stmt.cores.first.from = @table stmt.limit = Nodes::Limit.new(10) sql = compile(stmt) sql.must_be_like "SELECT _t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY \"users\".\"id\") as _row_num FROM \"users\") as _t WHERE _row_num BETWEEN 1 AND 10" end it 'should go over query ORDER BY if .order()' do stmt = Nodes::SelectStatement.new stmt.limit = Nodes::Limit.new(10) stmt.orders << Nodes::SqlLiteral.new('order_by') sql = compile(stmt) sql.must_be_like "SELECT _t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY order_by) as _row_num) as _t WHERE _row_num BETWEEN 1 AND 10" end it 'should go over query GROUP BY if no .order() and there is .group()' do stmt = Nodes::SelectStatement.new stmt.cores.first.groups << Nodes::SqlLiteral.new('group_by') stmt.limit = Nodes::Limit.new(10) sql = compile(stmt) sql.must_be_like "SELECT _t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY group_by) as _row_num GROUP BY group_by) as _t WHERE _row_num BETWEEN 1 AND 10" end it 'should use BETWEEN if both .limit() and .offset' do stmt = Nodes::SelectStatement.new stmt.limit = Nodes::Limit.new(10) stmt.offset = Nodes::Offset.new(20) sql = compile(stmt) sql.must_be_like "SELECT _t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY ) as _row_num) as _t WHERE _row_num BETWEEN 21 AND 30" end it 'should use >= if only .offset' do stmt = Nodes::SelectStatement.new stmt.offset = Nodes::Offset.new(20) sql = compile(stmt) sql.must_be_like "SELECT _t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY ) as _row_num) as _t WHERE _row_num >= 21" end it 'should generate subquery for .count' do stmt = Nodes::SelectStatement.new stmt.limit = Nodes::Limit.new(10) stmt.cores.first.projections << Nodes::Count.new('*') sql = compile(stmt) sql.must_be_like "SELECT COUNT(1) as count_id FROM (SELECT _t.* FROM (SELECT ROW_NUMBER() OVER (ORDER BY ) as _row_num) as _t WHERE _row_num BETWEEN 1 AND 10) AS subquery" end end end end