1、Mybatis-pluswrapper構(gòu)建和使、wapper介紹Wrapper ： 條件構(gòu)造抽象類，最頂端類AbstractWrapper ： 于查詢條件封裝，成 sql 的 where 條件QueryWrapper ： Entity 對象封裝操作類，不是lambda語法UpdateWrapper ： Update 條件封裝，于Entity對象更新操作AbstractLambdaWrapper ： Lambda 語法使 Wrapper統(tǒng)處理解析 lambda 獲取 column。LambdaQueryWrapper ：看名稱也能明就是于Lambda語法使的查詢WrapperLambdaUpda

2、teWrapper ： Lambda 更新封裝WrapperSpringBootTestpublic class QueryWrapperTests Autowiredprivate UserMapper userMapper;、AbstractWrapper注意：以下條件構(gòu)造器的法參中的column 均表數(shù)據(jù)庫字段、Testpublic void testDelete() QueryWrapper queryWrapper = new QueryWrapper();queryWrapper.isNull(name).ge(age, 12)System.out.println(delete r

3、eturn count = + result);SQL：UPDATE user SET deleted=1 WHERE deleted=0 AND name IS NULL AND age = ? AND email IS NOT NULL、注意：seletOne返回的是條實體記錄，當出現(xiàn)多條時會報錯TestQueryWrapper queryWrapper = new QueryWrapper();queryWrapper.eq(name, Tom);User user = userMapper.selectOne(queryWrapper);System.out.println(user)

4、;、包含邊界TestQueryWrapper queryWrapper = new QueryWrapper();queryWrapper.between(age, 20, 30);System.out.println(count);SELECT COUNT(1) FROM user WHERE deleted=0 AND age BETWEEN ? AND ?、Testpublic void testSelectList() QueryWrapper queryWrapper = new QueryWrapper();Map map = new HashMap();map.put(id, 2

5、);map.put(name, Jack);map.put(age, 20);9queryWrapper.allEq(map);List users = userMapper.selectList(queryWrapper);users.forEach(System.out:println);SELECT id,name,age,email,create_time,update_time,deleted,version FROM user WHERE deleted=0 AND name = ? AND id = ?AND age = ?、selectMaps返回Map集合列表TestQuer

6、yWrapper queryWrapper = new QueryWrapper();maps.forEach(System.out:println);SELECT id,name,age,email,create_time,update_time,deleted,version FROM user WHERE deleted=0 AND name NOT LIKE ?AND email LIKE ?、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：

7、可以實現(xiàn)查詢例:inSql(age, 1,2,3,4,5,6)-age in (1,2,3,4,5,6)例:inSql(id, select id from table where id id in (select id from table where id 3)Testpublic void testSelectObjs() QueryWrapper queryWrapper = new QueryWrapper();/queryWrapper.in(id, 1, 2, 3);queryWrapper.inSql(id, select id from user where id 3);Li

8、st objects = userMapper.selectObjs(queryWrapper);/ Object列表objects.forEach(System.out:println);SELECT id,name,age,email,create_time,update_time,deleted,version FROM user WHERE deleted=0 AND id IN (select id fromuser where id i.eq(name, ).ne(age, 20);int result = userMapper.update(user, userUpdateWra

9、pper);System.out.println(result);UPDATE user SET name=?, age=?, update_time=?WHERE deleted=0 AND name LIKE ?OR ( name = ? AND age ? )、TestQueryWrapper queryWrapper = new QueryWrapper();queryWrapper.orderByDesc(id);users.forEach(System.out:println);SELECT id,name,age,email,create_time,update_time,del

10、eted,versionFROM user WHERE deleted=0 ORDER BY id DESC、直接拼接到 sql 的最后注意：只能調(diào)次,多次調(diào)以最后次為準 有sql注的風險,請謹慎使Testusers.forEach(System.out:println);SELECT id,name,age,email,create_time,update_time,deleted,versionFROM user WHERE deleted=0 limit 1Testpublic void testSelectListColumn() QueryWrapper queryWrapper = new QueryWrapper();queryWrapper.select(id, name, age);List users = userMapper.selectList(queryWrapper);users.forEach(System.out:println);SELECT id,name,age FROM user WHERE deleted=0、最終的sql會合并 user.setAge()，以及 userUpdateWrapper.set() 和 setSql() 中 的字段Test/修改條件.like(name, h).set(name, )/set設(shè)置修改的字段