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This article mainly introduces what the common methods of MybatisPlus QueryWrapper have related knowledge, the content is detailed and easy to understand, the operation is simple and fast, has a certain reference value, I believe you will have some gains after reading this article on common methods of MybatisPlus QueryWrapper, let's take a look at it.

Common methods of QueryWrapper

MybatisPlus uses QueryWrapper test cases I, ge, gt, le, lt, isNull, isNotNull@Testpublic void testQuery () {QueryWrapper queryWrapper = new QueryWrapper (); queryWrapper .isNull ("name") .ge ("age", 12) .isNotNull ("email"); int result = userMapper.delete (queryWrapper); System.out.println ("delete return count =" + result) } II. Eq, ne@Testpublic void testSelectOne () {QueryWrapper queryWrapper = new QueryWrapper (); queryWrapper.eq ("name", "Tom"); Useruser = userMapper.selectOne (queryWrapper); / / only one record can be returned, and an exception System.out.println (user) will be thrown;} III, between, notBetween@Testpublic void testSelectCount () {QueryWrapper queryWrapper = new QueryWrapper (); queryWrapper.between ("age", 20,30) Integer count = userMapper.selectCount (queryWrapper); / / return data quantity System.out.println (count);} IV, like, notLike, likeLeft, likeRight@Testpublic void testSelectMaps () {QueryWrapper queryWrapper = new QueryWrapper (); queryWrapper .select ("name", "age") .like ("name", "e") .like right ("email", "5"); List maps = userMapper.selectMaps (queryWrapper) / / the return value is Map list maps.forEach (System.out::println);} V, orderBy, orderByDesc, orderByAsc@Testpublic void testSelectListOrderBy () {QueryWrapper queryWrapper = new QueryWrapper (); queryWrapper.orderByDesc ("age", "id"); Listusers = userMapper.selectList (queryWrapper); users.forEach (System.out::println);} VI. Insert insert@Testpublic void save () {User user = new User (); user.setAge (23) User.setEmail ("test"); user.setName ("test"); / / 1. Add userService.save (user) using service; / / 2. Add userMapper.insert (user) using mapper; 7. Delete remove@Testpublic void delete () {/ / delete userService.remove (Wrappers.query (). Lambda (). Eq (User::getAge, 3));} 8. Modify update@Testpublic void update () {User user = new User (); user.setAge (23); user.setEmail ("344"); user.setName ("test333"); UpdateWrapper updateWrapper = new UpdateWrapper () UpdateWrapper.eq ("id", "1"); / / 1.user encapsulates the modified attribute value, and updateWrapper encapsulates the modified conditional parameter value userService.update (user,updateWrapper); / / 2. Modify the corresponding parameter attribute value userService.update (Wrappers.update (). Lambda (). Set (User::getName, "2") .eq (User::getAge, 23)) according to the condition; / / 3. Determine whether the parameter is empty, and modify String name = "name"; userService.update (Wrappers.update (). Lambda (). Set (StringUtils.isNotBlank (name), User::getName, name) .eq (User::getAge, 23);} this is the end of the article on "what are the common methods of MybatisPlus QueryWrapper". Thank you for reading! I believe you all have a certain understanding of "what are the common methods of MybatisPlus QueryWrapper". If you want to learn more, you are welcome to follow the industry information channel.

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