filter_last.go

// Copyright 2020 io.xream.sqlxb
//
// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements.  See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License.  You may obtain a copy of the License at
//
//	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package sqlxb

func (built *Built) filterLast() *Bb {
	if built.PageCondition == nil {
		return nil
	}
	if built.PageCondition.rows == 0 {
		panic("page.rows must be greater than 0")
	}
	if built.PageCondition.last > 0 {

		if built.Sorts == nil || len(built.Sorts) == 0 {
			panic("last > 0, Numeric sorts[0] required")
		}
		sort := built.Sorts[0]
		var gl string
		if sort.direction == asc {
			gl = GT
		} else {
			gl = LT
		}
		return &Bb{
			op:    gl,
			key:   sort.orderBy,
			value: built.PageCondition.last,
		}
	}
	return nil
}