/**
* Copyright (c) 2011-2020, hubin (jobob@qq.com).
* <p>
* Licensed 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
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* 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 com.baomidou.mybatisplus.mapper;
import com.baomidou.mybatisplus.MybatisAbstractSQL;
import com.baomidou.mybatisplus.toolkit.StringUtils;
/**
* <p>
* 实现AbstractSQL ,实现WHERE条件自定义
* </p>
*
* @author yanghu , Caratacus
* @Date 2016-08-22
*/
@SuppressWarnings("serial")
public class SqlPlus extends MybatisAbstractSQL<SqlPlus> {
private final String IS_NOT_NULL = " IS NOT NULL";
private final String IS_NULL = " IS NULL";
@Override
public SqlPlus getSelf() {
return this;
}
/**
* IS NOT NULL查询
*
* @param columns 以逗号分隔的字段名称
* @return this
*/
public SqlPlus IS_NOT_NULL(String columns) {
handerNull(columns, IS_NOT_NULL);
return this;
}
/**
* IS NULL查询
*
* @param columns 以逗号分隔的字段名称
* @return
*/
public SqlPlus IS_NULL(String columns) {
handerNull(columns, IS_NULL);
return this;
}
/**
* 将EXISTS语句添加到WHERE条件中
*
* @param value
* @return
*/
public SqlPlus EXISTS(String value) {
handerExists(value, false);
return this;
}
/**
* 处理EXISTS操作
*
* @param value
* @param isNot 是否为NOT EXISTS操作
*/
private void handerExists(String value, boolean isNot) {
if (StringUtils.isNotEmpty(value)) {
StringBuilder inSql = new StringBuilder();
if (isNot) {
inSql.append(" NOT");
}
inSql.append(" EXISTS (").append(value).append(")");
WHERE(inSql.toString());
}
}
/**
* 将NOT_EXISTS语句添加到WHERE条件中
*
* @param value
* @return
*/
public SqlPlus NOT_EXISTS(String value) {
handerExists(value, true);
return this;
}
/**
* 以相同的方式处理null和notnull
*
* @param columns 以逗号分隔的字段名称
* @param sqlPart SQL部分
*/
private void handerNull(String columns, String sqlPart) {
if (StringUtils.isNotEmpty(columns)) {
String[] cols = columns.split(",");
for (String col : cols) {
if (StringUtils.isNotEmpty(col.trim())) {
WHERE(col + sqlPart);
}
}
}
}
}