• Mybatis-Plus条件构造器

    目录

    Mybatis-Plus条件构造器

    1、allEq：全部

    2、eq：等于

    3、ne：不等于

    4、gt：大于

    5、ge：大于等于

    6、lt：小于

    7、le：小于等于

    8、between：两者之间

    9、notBetween：两者之外

    10、like：模糊查询

    11、notLike：模糊查询

    12、likeLeft：

    13、likeRight

    14、isNull

    15、isNotNull

    15、in

    16、notIn

    17、inSql

    18、notInSql

    19、groupBy

    20、orderByAsc

    21、orderByDesc

    22、orderBy

    23、having

    24、or

    25、and

    26、nested

    27、last

    28、exists

    29、notExists

    QueryWrapper

    30、select

    UpdateWrapper

    31、set

    32、lambda

    Mybatis-Plus条件构造器

    1、allEq：全部

    1. allEq(Map params)
    2. allEq(Map params, boolean null2IsNull)
    3. allEq(boolean condition, Map params, boolean null2IsNull)

     全部eq(或个别isNull)

    个别参数说明:

    params : key为数据库字段名,value为字段值
    null2IsNull : 为true则在map的value为null时调用 isNull 方法,为false时则忽略value为null的

     示例：

    1. @Test
    2.     public void AllEq() {
    3.         //设置条件
    4.         Map<String,Object> params = new HashMap<>();
    5.         params.put("name", "坤坤");
    6.         params.put("age", "18");
    7.         params.put("password", null);
    8.         QueryWrapper<Users> wrapper = new QueryWrapper<>();
    9.         //SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE password IS NULL AND name = ? AND age = ?
    10.         //wrapper.allEq(params);
    11.  
    12.         //去掉为空的条件
    13.         //SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? AND age = ?
    14.         //wrapper.allEq(params,false);
    15.  
    16.         //过滤条件
    17.         //SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ?
    18.         wrapper.allEq((k, v) -> (k.equals("name") || k.equals("id")),params);
    19.         //SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? AND age = ?
    20.         wrapper.allEq((k, v) -> (k.equals("name") || k.equals("age")),params);
    21.         
    22.         List<Users> users = this.userMapper.selectList(wrapper);
    23.         for (Users user : users) {
    24.             System.out.println(user);
    25.         }
    26.  
    27.     }

    2、eq：等于

    1. eq(R column, Object val)
    2. eq(boolean condition, R column, Object val)
    • 等于 =
    • 例: eq("name", "老王")--->name = '老王'

    示例： 

    1. //查询一条数据
    2.     @Test
    3.     public void selectOne() {
    4.  
    5.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    6.         queryWrapper.eq("user_name","11");
    7.         //查询一条，如果多余1条会报异常
    8.         Users user = this.userMapper.selectOne(queryWrapper);
    9.         System.out.println("result = " + user);
    10.     }

    3、ne：不等于

    1. ne(R column, Object val)
    2. ne(boolean condition, R column, Object val)
    • 不等于 <>
    • 例: ne("name", "老王")--->name <> '老王'

    示例：

    1. //不等于
    2.     @Test
    3.     public void selectListNe() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name <> ? 
    6.         queryWrapper.ne("name","王五");
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    4、gt：大于

    1. gt(R column, Object val)
    2. gt(boolean condition, R column, Object val)
    • 大于 >
    • 例: gt("age", 18)--->age > 18
    1. //大于
    2.     @Test
    3.     public void selectListGt() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age > ? 
    6.         queryWrapper.gt("age","20");
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    5、ge：大于等于

    1. ge(R column, Object val)
    2. ge(boolean condition, R column, Object val)
    • 大于等于 >=
    • 例: ge("age", 18)--->age >= 18
    1. //大于等于
    2.     @Test
    3.     public void selectListGe() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age >= ? 
    6.         queryWrapper.ge("age","20");//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    6、lt：小于

    1. lt(R column, Object val)
    2. lt(boolean condition, R column, Object val)
    • 小于 <
    • 例: lt("age", 18)--->age < 18
    1.  //小于
    2.     @Test
    3.     public void selectListLt() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age < ?
    6.         queryWrapper.lt("age","20");//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    7、le：小于等于

    1. le(R column, Object val)
    2. le(boolean condition, R column, Object val)
    • 小于等于 <=
    • 例: le("age", 18)--->age <= 18
    1. //小于等于
    2.     @Test
    3.     public void selectListLe() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age <= ?
    6.         queryWrapper.le("age","20");//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    8、between：两者之间

    1. between(R column, Object val1, Object val2)
    2. between(boolean condition, R column, Object val1, Object val2)
    • BETWEEN 值1 AND 值2
    • 例: between("age", 18, 30)--->age between 18 and 30
    1. //两者之间
    2.     @Test
    3.     public void selectListBetween() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age BETWEEN ? AND ?
    6.         queryWrapper.between("age",15,20);//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    9、notBetween：两者之外

    1. notBetween(R column, Object val1, Object val2)
    2. notBetween(boolean condition, R column, Object val1, Object val2)
    • NOT BETWEEN 值1 AND 值2
    • 例: notBetween("age", 18, 30)--->age not between 18 and 30
    1. //两者之外
    2.     @Test
    3.     public void selectListNotBetween() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age NOT BETWEEN ? AND ? 
    6.         queryWrapper.notBetween("age",15,20);//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    10、like：模糊查询

    1. like(R column, Object val)
    2. like(boolean condition, R column, Object val)
    • LIKE '%值%'
    • 例: like("name", "王")--->name like '%王%'
    1. //模糊查询
    2.     @Test
    3.     public void selectListLike() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name LIKE ?
    6.         queryWrapper.like("name","王");//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    11、notLike：模糊查询

    1. notLike(R column, Object val)
    2. notLike(boolean condition, R column, Object val)
    • NOT LIKE '%值%'
    • 例: notLike("name", "王")--->name not like '%王%'
    1. //模糊查询
    2.     @Test
    3.     public void selectListNotLike() {
    4.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    5.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name NOT LIKE ? 
    6.         queryWrapper.notLike("name","王");//
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    12、likeLeft：

    1. likeLeft(R column, Object val)
    2. likeLeft(boolean condition, R column, Object val)
    • LIKE '%值'
    • 例: likeLeft("name", "王")--->name like '%王'
    1. @Test
    2.     public void selectListLikeLeft() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name LIKE ? Parameters: %王(String)
    5.         queryWrapper.likeLeft("name","王");//查询年龄大于20的条数
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    13、likeRight

    1. likeRight(R column, Object val)
    2. likeRight(boolean condition, R column, Object val)
    • LIKE '值%'
    • 例: likeRight("name", "王")--->name like '王%'
    1. @Test
    2.     public void selectListLikeRight() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name LIKE ?   王%(String)
    5.         queryWrapper.likeRight("name","王");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    14、isNull

    1. isNull(R column)
    2. isNull(boolean condition, R column)
    • 字段 IS NULL
    • 例: isNull("name")--->name is null
    1.  @Test
    2.     public void selectListIsNull() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name IS NULL 
    5.         queryWrapper.isNull("name");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    15、isNotNull

    1. isNotNull(R column)
    2. isNotNull(boolean condition, R column)
    • 字段 IS NOT NULL
    • 例: isNotNull("name")--->name is not null
    1.  @Test
    2.     public void selectListIsNotNull() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name IS NOT NULL 
    5.         queryWrapper.isNotNull("name");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    15、in

    1. in(R column, Collection<?> value)
    2. in(boolean condition, R column, Collection<?> value)
    • 字段 IN (value.get(0), value.get(1), ...)
    • 例: in("age",{1,2,3})--->age in (1,2,3)
    1. in(R column, Object... values)
    2. in(boolean condition, R column, Object... values)
    • 字段 IN (v0, v1, ...)
    • 例: in("age", 1, 2, 3)--->age in (1,2,3)
    1.  @Test
    2.     public void selectListIn() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age IN (?,?,?)
    5.         queryWrapper.in("age",15,18,19);
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    16、notIn

    1. notIn(R column, Collection<?> value)
    2. notIn(boolean condition, R column, Collection<?> value)
    • 字段 NOT IN (value.get(0), value.get(1), ...)
    • 例: notIn("age",{1,2,3})--->age not in (1,2,3)
    1. notIn(R column, Object... values)
    2. notIn(boolean condition, R column, Object... values)
    • 字段 NOT IN (v0, v1, ...)
    • 例: notIn("age", 1, 2, 3)--->age not in (1,2,3)
    1.  @Test
    2.     public void selectListNotIn() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age NOT IN (?,?,?)
    5.         queryWrapper.notIn("age",15,18,19);
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    17、inSql

    1. inSql(R column, String inValue)
    2. inSql(boolean condition, R column, String inValue)
    • 字段 IN ( sql语句 )
    • 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 < 3")--->id in (select id from table where id < 3)
    1.   @Test
    2.     public void selectListInSql() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE id IN (select id from tb_user where id < 3)
    5.         queryWrapper.inSql("id", "select id from tb_user where id < 3");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    18、notInSql

    1. notInSql(R column, String inValue)
    2. notInSql(boolean condition, R column, String inValue)
    • 字段 NOT IN ( sql语句 )
    • 例: notInSql("age", "1,2,3,4,5,6")--->age not in (1,2,3,4,5,6)
    • 例: notInSql("id", "select id from table where id < 3")--->id not in (select id from table where id < 3)
    1.  @Test
    2.     public void selectListNotInSql() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE id NOT IN (select id from tb_user where id < 3) 
    5.         queryWrapper.notInSql("id", "select id from tb_user where id < 3");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    19、groupBy

    1. groupBy(R... columns)
    2. groupBy(boolean condition, R... columns)
    • 分组：GROUP BY 字段, ...
    • 例: groupBy("id", "name")--->group by id,name
    1.  @Test
    2.     public void selectListGroupBy() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user GROUP BY age
    5.         queryWrapper.groupBy("age");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    20、orderByAsc

    1. orderByAsc(R... columns)
    2. orderByAsc(boolean condition, R... columns)
    • 排序：ORDER BY 字段, ... ASC
    • 例: orderByAsc("id", "name")--->order by id ASC,name ASC
    1.   @Test
    2.     public void selectListOrderByAsc() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user ORDER BY age ASC 
    5.         queryWrapper.orderByAsc("age");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    21、orderByDesc

    1. orderByDesc(R... columns)
    2. orderByDesc(boolean condition, R... columns)
    • 排序：ORDER BY 字段, ... DESC
    • 例: orderByDesc("id", "name")--->order by id DESC,name DESC
    1.  @Test
    2.     public void selectListOrderByDesc() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user ORDER BY age DESC
    5.         queryWrapper.orderByDesc("age");
    6.         //根据条件查询集合
    7.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    8.         userList.forEach(System.out::println);
    9.     }

    22、orderBy

    orderBy(boolean condition, boolean isAsc, R... columns)
    • 排序：ORDER BY 字段, ...
    • 例: orderBy(true, true, "id", "name")--->order by id ASC,name ASC
    1.   @Test
    2.     public void selectListOrderByDesc() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user ORDER BY age ASC
    5.         /*Params:
    6.         condition – 执行条件
    7.         isAsc – 是否是 ASC 排序
    8.         columns – 字段数组
    9.         */
    10.         queryWrapper.orderBy(true,true,"age");
    11.         //根据条件查询集合
    12.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    13.         userList.forEach(System.out::println);
    14.     }

    23、having

    1. having(String sqlHaving, Object... params)
    2. having(boolean condition, String sqlHaving, Object... params)
    • HAVING ( sql语句 )
    • 例: having("sum(age) > 10")--->having sum(age) > 10
    • 例: having("sum(age) > {0}", 11)--->having sum(age) > 11
    1.  @Test
    2.     public void selectListHaving() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? HAVING sum(age) > 10
    5.         queryWrapper
    6.                 .eq("name","王五")
    7.                 .having("sum(age) > 10");
    8.         //根据条件查询集合
    9.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    10.         userList.forEach(System.out::println);
    11.     }

    24、or

    1. or()
    2. or(boolean condition)

    注意事项:

    主动调用or表示紧接着下一个方法不是用and连接!(不调用or则默认为使用and连接)

    eq("id",1).or().eq("name","老王")--->id = 1 or name = '老王' 

    1.  @Test
    2.     public void selectListOr() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? OR age = ? 
    5.         queryWrapper
    6.                 .eq("name","王五")
    7.                 .or()
    8.                 .eq("age","20");
    9.         //根据条件查询集合
    10.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    11.         userList.forEach(System.out::println);
    12.     }
    1. or(Consumer<Param> consumer)
    2. or(boolean condition, Consumer<Param> consumer)
    • OR 嵌套
    • 例: or(i -> i.eq("name", "李白").ne("status", "活着"))--->or (name = '李白' and status <> '活着')

    25、and

    1. and(Consumer<Param> consumer)
    2. and(boolean condition, Consumer<Param> consumer)
    • AND 嵌套
    • 例: and(i -> i.eq("name", "李白").ne("status", "活着"))--->and (name = '李白' and status <> '活着')
    1.  @Test
    2.     public void selectListAnd() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? AND ( age = ? ) 
    5.         queryWrapper
    6.                 .eq("name","王五")
    7.                 .and(i -> i.eq("age", "18"));
    8.         //根据条件查询集合
    9.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    10.         userList.forEach(System.out::println);
    11.     }

    26、nested

    1. nested(Consumer<Param> consumer)
    2. nested(boolean condition, Consumer<Param> consumer)
    • 正常嵌套 不带 AND 或者 OR
    • 例: nested(i -> i.eq("name", "李白").ne("status", "活着"))--->(name = '李白' and status <> '活着')

    27、last

    1. last(String lastSql)
    2. last(boolean condition, String lastSql)

    无视优化规则直接拼接到 sql 的最后 

    注意事项:

    只能调用一次,多次调用以最后一次为准 有sql注入的风险,请谨慎使用

    last("limit 1")

    28、exists

    1. exists(String existsSql)
    2. 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)​​​​​​​

    29、notExists

    1. notExists(String notExistsSql)
    2. notExists(boolean condition, String notExistsSql)
    • 拼接 NOT EXISTS ( sql语句 )
    • 例: notExists("select id from table where age = 1")--->not exists (select id from table where age = 1)

    QueryWrapper

    说明:

    继承自 AbstractWrapper ,自身的内部属性 entity 也用于生成 where 条件
    及 LambdaQueryWrapper, 可以通过 new QueryWrapper().lambda() 方法获取

    30、select

    1. select(String... sqlSelect)
    2. select(Predicate<TableFieldInfo> predicate)
    3. select(Class<T> entityClass, Predicate<TableFieldInfo> predicate)

    设置查询字段

    说明:

    以上方法分为两类.
    第二类方法为:过滤查询字段(主键除外),入参不包含 class 的调用前需要wrapper内的entity属性有值! 这两类方法重复调用以最后一次为准

    • 例: select("id", "name", "age")
    • 例: select(i -> i.getProperty().startsWith("test"))
    1.  @Test
    2.     public void selectListExists() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,name,age FROM tb_user
    5.         queryWrapper
    6.                 .exists("select id from tb_user where age = 18");
    7.         //根据条件查询集合
    8.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    9.         userList.forEach(System.out::println);
    10.     }

    UpdateWrapper

    说明:

    继承自 AbstractWrapper ,自身的内部属性 entity 也用于生成 where 条件
    及 LambdaUpdateWrapper, 可以通过 new UpdateWrapper().lambda() 方法获取!

    31、set

    1. set(String column, Object val)
    2. set(boolean condition, String column, Object val)
    • SQL SET 字段
    • 例: set("name", "老李头")
    • 例: set("name", "")--->数据库字段值变为空字符串
    • 例: set("name", null)--->数据库字段值变为null
    1.  @Test
    2.     public void selectListSet() {
    3.         UpdateWrapper<Users> updateWrapper = new UpdateWrapper<>();
    4.         //SQL: UPDATE tb_user SET name=?
    5.         //修改全部
    6.         updateWrapper
    7.                 .set("name", "老李头");
    8.         //根据条件查询集合
    9.         int update = this.userMapper.update(null, updateWrapper);
    10.         System.out.println(update);
    11.     }
    1.  @Test
    2.     public void selectListSetSql() {
    3.         UpdateWrapper<Users> updateWrapper = new UpdateWrapper<>();
    4.         //SQL: UPDATE tb_user SET age = age + 1 WHERE name = ? 
    5.         //根据条件修改
    6.         updateWrapper
    7.                 .setSql("age = age + 1").eq("name","老李头");
    8.         //根据条件查询集合
    9.         int update = this.userMapper.update(null, updateWrapper);
    10.         System.out.println(update);
    11.     }

    32、lambda

    • 获取 LambdaWrapper
      在QueryWrapper中是获取LambdaQueryWrapper
      在UpdateWrapper中是获取LambdaUpdateWrapper
    1.  @Test
    2.     public void selectListLambda() {
    3.         QueryWrapper<Users> queryWrapper = new QueryWrapper<>();
    4.         //SQL: SELECT id,name,age FROM tb_user
    5.         queryWrapper
    6.                 .lambda()
    7.                 .select(Users::getId,Users::getAge,Users::getName)
    8.                 .like(Users::getName,"老");
    9.         //根据条件查询集合
    10.         List<Users> userList = this.userMapper.selectList(queryWrapper);
    11.         userList.forEach(System.out::println);
    12.     }

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  • 原文地址：https://blog.csdn.net/qi341500/article/details/132781582