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
allEq(Map params)
allEq(Map params, boolean null2IsNull)
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：
@Test
public void AllEq() {
//设置条件
Map params = new HashMap<>();
params.put("name", "坤坤");
params.put("age", "18");
params.put("password", null);
QueryWrapper wrapper = new QueryWrapper<>();
//SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE password IS NULL AND name = ? AND age = ?
//wrapper.allEq(params);
//去掉为空的条件
//SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? AND age = ?
//wrapper.allEq(params,false);
//过滤条件
//SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ?
wrapper.allEq((k, v) -> (k.equals("name") || k.equals("id")),params);
//SQL:SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? AND age = ?
wrapper.allEq((k, v) -> (k.equals("name") || k.equals("age")),params);
List users = this.userMapper.selectList(wrapper);
for (Users user : users) {
System.out.println(user);
}
} 2、eq：等于
eq(R column, Object val)
eq(boolean condition, R column, Object val)- 等于 =
- 例:
eq("name", "老王")--->name = '老王'
示例：
//查询一条数据
@Test
public void selectOne() {
QueryWrapper queryWrapper = new QueryWrapper<>();
queryWrapper.eq("user_name","11");
//查询一条，如果多余1条会报异常
Users user = this.userMapper.selectOne(queryWrapper);
System.out.println("result = " + user);
} 3、ne：不等于
ne(R column, Object val)
ne(boolean condition, R column, Object val)- 不等于 <>
- 例:
ne("name", "老王")--->name <> '老王'
示例：
//不等于
@Test
public void selectListNe() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name <> ?
queryWrapper.ne("name","王五");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 4、gt：大于
gt(R column, Object val)
gt(boolean condition, R column, Object val)- 大于 >
- 例:
gt("age", 18)--->age > 18
//大于
@Test
public void selectListGt() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age > ?
queryWrapper.gt("age","20");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 5、ge：大于等于
ge(R column, Object val)
ge(boolean condition, R column, Object val)- 大于等于 >=
- 例:
ge("age", 18)--->age >= 18
//大于等于
@Test
public void selectListGe() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age >= ?
queryWrapper.ge("age","20");//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
}
6、lt：小于
lt(R column, Object val)
lt(boolean condition, R column, Object val)- 小于 <
- 例:
lt("age", 18)--->age < 18
//小于
@Test
public void selectListLt() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age < ?
queryWrapper.lt("age","20");//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 7、le：小于等于
le(R column, Object val)
le(boolean condition, R column, Object val)- 小于等于 <=
- 例:
le("age", 18)--->age <= 18
//小于等于
@Test
public void selectListLe() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age <= ?
queryWrapper.le("age","20");//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 8、between：两者之间
between(R column, Object val1, Object val2)
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
//两者之间
@Test
public void selectListBetween() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age BETWEEN ? AND ?
queryWrapper.between("age",15,20);//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 9、notBetween：两者之外
notBetween(R column, Object val1, Object val2)
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
//两者之外
@Test
public void selectListNotBetween() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age NOT BETWEEN ? AND ?
queryWrapper.notBetween("age",15,20);//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 10、like：模糊查询
like(R column, Object val)
like(boolean condition, R column, Object val)- LIKE '%值%'
- 例:
like("name", "王")--->name like '%王%'
//模糊查询
@Test
public void selectListLike() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name LIKE ?
queryWrapper.like("name","王");//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 11、notLike：模糊查询
notLike(R column, Object val)
notLike(boolean condition, R column, Object val)- NOT LIKE '%值%'
- 例:
notLike("name", "王")--->name not like '%王%'
//模糊查询
@Test
public void selectListNotLike() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name NOT LIKE ?
queryWrapper.notLike("name","王");//
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 12、likeLeft：
likeLeft(R column, Object val)
likeLeft(boolean condition, R column, Object val)- LIKE '%值'
- 例:
likeLeft("name", "王")--->name like '%王'
@Test
public void selectListLikeLeft() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name LIKE ? Parameters: %王(String)
queryWrapper.likeLeft("name","王");//查询年龄大于20的条数
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 13、likeRight
likeRight(R column, Object val)
likeRight(boolean condition, R column, Object val)- LIKE '值%'
- 例:
likeRight("name", "王")--->name like '王%'
@Test
public void selectListLikeRight() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name LIKE ? 王%(String)
queryWrapper.likeRight("name","王");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 14、isNull
isNull(R column)
isNull(boolean condition, R column)- 字段 IS NULL
- 例:
isNull("name")--->name is null
@Test
public void selectListIsNull() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name IS NULL
queryWrapper.isNull("name");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 15、isNotNull
isNotNull(R column)
isNotNull(boolean condition, R column)- 字段 IS NOT NULL
- 例:
isNotNull("name")--->name is not null
@Test
public void selectListIsNotNull() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name IS NOT NULL
queryWrapper.isNotNull("name");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 15、in
in(R column, Collection value)
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)
in(R column, Object... values)
in(boolean condition, R column, Object... values)- 字段 IN (v0, v1, ...)
- 例:
in("age", 1, 2, 3)--->age in (1,2,3)
@Test
public void selectListIn() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age IN (?,?,?)
queryWrapper.in("age",15,18,19);
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
}
16、notIn
notIn(R column, Collection value)
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)
notIn(R column, Object... values)
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)
@Test
public void selectListNotIn() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE age NOT IN (?,?,?)
queryWrapper.notIn("age",15,18,19);
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 17、inSql
inSql(R column, String inValue)
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)
@Test
public void selectListInSql() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE id IN (select id from tb_user where id < 3)
queryWrapper.inSql("id", "select id from tb_user where id < 3");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 18、notInSql
notInSql(R column, String inValue)
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)
@Test
public void selectListNotInSql() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE id NOT IN (select id from tb_user where id < 3)
queryWrapper.notInSql("id", "select id from tb_user where id < 3");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 19、groupBy
groupBy(R... columns)
groupBy(boolean condition, R... columns)- 分组：GROUP BY 字段, ...
- 例:
groupBy("id", "name")--->group by id,name
@Test
public void selectListGroupBy() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user GROUP BY age
queryWrapper.groupBy("age");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 20、orderByAsc
orderByAsc(R... columns)
orderByAsc(boolean condition, R... columns)- 排序：ORDER BY 字段, ... ASC
- 例:
orderByAsc("id", "name")--->order by id ASC,name ASC
@Test
public void selectListOrderByAsc() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user ORDER BY age ASC
queryWrapper.orderByAsc("age");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 21、orderByDesc
orderByDesc(R... columns)
orderByDesc(boolean condition, R... columns)- 排序：ORDER BY 字段, ... DESC
- 例:
orderByDesc("id", "name")--->order by id DESC,name DESC
@Test
public void selectListOrderByDesc() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user ORDER BY age DESC
queryWrapper.orderByDesc("age");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 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
@Test
public void selectListOrderByDesc() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user ORDER BY age ASC
/*Params:
condition – 执行条件
isAsc – 是否是 ASC 排序
columns – 字段数组
*/
queryWrapper.orderBy(true,true,"age");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 23、having
having(String sqlHaving, Object... params)
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
@Test
public void selectListHaving() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? HAVING sum(age) > 10
queryWrapper
.eq("name","王五")
.having("sum(age) > 10");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 24、or
or()
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'
@Test
public void selectListOr() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? OR age = ?
queryWrapper
.eq("name","王五")
.or()
.eq("age","20");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} or(Consumer consumer)
or(boolean condition, Consumer 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
and(Consumer consumer)
and(boolean condition, Consumer consumer)- AND 嵌套
- 例:
and(i -> i.eq("name", "李白").ne("status", "活着"))--->and (name = '李白' and status <> '活着')
@Test
public void selectListAnd() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,user_name,password,name,age,email FROM tb_user WHERE name = ? AND ( age = ? )
queryWrapper
.eq("name","王五")
.and(i -> i.eq("age", "18"));
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 26、nested
nested(Consumer consumer)
nested(boolean condition, Consumer 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
last(String lastSql)
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
exists(String existsSql)
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
notExists(String notExistsSql)
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
select(String... sqlSelect)
select(Predicate predicate)
select(Class entityClass, Predicate 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"))
@Test
public void selectListExists() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,name,age FROM tb_user
queryWrapper
.exists("select id from tb_user where age = 18");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
} 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
set(String column, Object val)
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
@Test
public void selectListSet() {
UpdateWrapper updateWrapper = new UpdateWrapper<>();
//SQL: UPDATE tb_user SET name=?
//修改全部
updateWrapper
.set("name", "老李头");
//根据条件查询集合
int update = this.userMapper.update(null, updateWrapper);
System.out.println(update);
} @Test
public void selectListSetSql() {
UpdateWrapper updateWrapper = new UpdateWrapper<>();
//SQL: UPDATE tb_user SET age = age + 1 WHERE name = ?
//根据条件修改
updateWrapper
.setSql("age = age + 1").eq("name","老李头");
//根据条件查询集合
int update = this.userMapper.update(null, updateWrapper);
System.out.println(update);
} 32、lambda
- 获取
LambdaWrapper
在QueryWrapper中是获取LambdaQueryWrapper
在UpdateWrapper中是获取LambdaUpdateWrapper
@Test
public void selectListLambda() {
QueryWrapper queryWrapper = new QueryWrapper<>();
//SQL: SELECT id,name,age FROM tb_user
queryWrapper
.lambda()
.select(Users::getId,Users::getAge,Users::getName)
.like(Users::getName,"老");
//根据条件查询集合
List userList = this.userMapper.selectList(queryWrapper);
userList.forEach(System.out::println);
}