exists:拼接 EXISTS ( sql语句 ),notExists:拼接 NOT EXISTS ( sql语句 ) 测试: @Test public void contextLoads(){ QueryWrapper<Employee> existsWrapper = new QueryWrapper<>(); //exists() 查询符合sql语句的值 existsWrapper.exists("select last_name,gender from employee where id = 1"); List<Emplo...
exists(boolean condition, String existsSql) 拼接EXISTS ( sql语句 ) 例: exists("select id from table where age = 1")--->exists (select id from table where age = 1) #notExists notExists(String notExistsSql) notExists(boolean condition, String notExistsSql) 拼接NOT EXISTS ( sql语句 ) 例...
拼接NOT EXISTS ( sql语句 ) notExists(String notExistsSql) notExists(boolean condition, String notExistsSql) 例如如下例子,若exists中的内容用户可控,则会存在注入风险: QueryWrapper<User> qw = new QueryWrapper<>(); qw.select("id","name").exists("select id from table where role_id = 2"); h...
6、in、notIn、inSql、notinSql、exists、notExists in、notIn: notIn(“age”,{1,2,3})—>age not in (1,2,3) notIn(“age”, 1, 2, 3)—>age not in (1,2,3) inSql、notinSql:可以实现子查询 例: inSql(“age”, “1,2,3,4,5,6”)—>age in (1,2,3,4,5,6) 例: inS...
existsEXISTS 条件语句 notExistsNOT EXISTS 条件语句 betweenBETWEEN 条件语句 notBetweenNOT BETWEEN 条件语句 addFilter自由拼接 SQL last拼接在最后,例如:last(“LIMIT 1”) 测试用例 1 ge、gt、le、lt、isNull、isNotNull Test public void testDelete() { QueryWrapper<User> queryWrapper = new QueryWrapper<>...
在SQL语句中,exists是一个用于判断子查询返回结果是否存在的关键字。它会根据子查询的结果集返回一个布尔值,如果结果集非空则返回`true`,否则返回`false`。 MyBatis Plus在这个基础上进行了封装,提供了一个便利的方法来处理exists查询。 二、MyBatis Plus中的exists方法是如何使用的? 在MyBatis Plus中,exists方法...
EXISTS("EXISTS"), NOT_EXISTS("NOT EXISTS"), BETWEEN("BETWEEN"), NOT_BETWEEN("NOT BETWEEN"), ASC("ASC"), DESC("DESC"); privatefinal String keyword; publicString getSqlSegment() { return this.keyword; } privateSqlKeyword(final String keyword) { ...
步骤一:定义一个UserMapper接口,继承BaseMapper接口,并添加一个exists方法。 java public interface UserMapper extends BaseMapper<User> { boolean existUser(@Param(Constants.WRAPPER) Wrapper<User> wrapper); } 步骤二:在UserMapper.xml中编写exists的SQL语句。 xml SELECT EXISTS( SELECT 1 FROM user {ew.cust...
6、in、notIn、inSql、notinSql、exists、notExists in、notIn: notIn(“age”,{1,2,3})—>age not in (1,2,3) notIn(“age”, 1, 2, 3)—>age not in (1,2,3) inSql、notinSql:可以实现子查询 例: inSql(“age”, “1,2,3,4,5,6”)—>age in (1,2,3,4,5,6) ...
exists(String existsSql); // 拼接 exists 语句。例: exists("select id from table where age = 1") ---> exists (select id from table where age = 1) 【QueryWrapper 条件:】 select(String... sqlSelect); // 用于定义需要返回的字段。例: select("id", "name", "age") ---> select id...