官方文档说明:
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以下出现的第一个入参
boolean condition表示该条件是否加入最后生成的sql中 -
以下代码块内的多个方法均为从上往下补全个别
boolean类型的入参,默认为true -
以下出现的泛型
Param均为Wrapper的子类实例(均具有AbstractWrapper的所有方法) -
以下方法在入参中出现的
R为泛型,在普通wrapper中是String -
以下方法入参中的
R column均表示数据库字段,当R具体类型为String时则为数据库字段名(字段名是数据库关键字的自己用转义符包裹!)!而不是实体类数据字段名!!!,另当R具体类型为SFunction时项目runtime不支持eclipse自家的编译器!!! -
以下举例均为使用普通wrapper,入参为
Map和List的均以json形式表现! -
使用中如果入参的
Map或者List为空,则不会加入最后生成的sql中!!!
警告:
不支持以及不赞成在 RPC 调用中把 Wrapper 进行传输
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wrapper 很重
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传输 wrapper 可以类比为你的 controller 用 map 接收值(开发一时爽,维护火葬场)
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正确的 RPC 调用姿势是写一个 DTO 进行传输,被调用方再根据 DTO 执行相应的操作
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我们拒绝接受任何关于 RPC 传输 Wrapper 报错相关的 issue 甚至 pr
AbstractWrapper
说明:
QueryWrapper(LambdaQueryWrapper) 和 UpdateWrapper(LambdaUpdateWrapper) 的父类 用于生成 sql 的 where 条件, entity 属性也用于生成 sql 的 where 条件 注意: entity 生成的 where 条件与 使用各个 api 生成的 where 条件没有任何关联行为
allEq
allEq(Map<R, V> params)
allEq(Map<R, V> params, boolean null2IsNull)
allEq(boolean condition, Map<R, V> params, boolean null2IsNull)
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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
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例1:
allEq({id:1,name:"老王",age:null})--->id = 1 and name = '老王' and age is null -
例2:
allEq({id:1,name:"老王",age:null}, false)--->id = 1 and name = '老王'
allEq(BiPredicate<R, V> filter, Map<R, V> params)
allEq(BiPredicate<R, V> filter, Map<R, V> params, boolean null2IsNull)
allEq(boolean condition, BiPredicate<R, V> filter, Map<R, V> params, boolean null2IsNull)
个别参数说明:
filter : 过滤函数,是否允许字段传入比对条件中 params 与 null2IsNull : 同上
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例1:
allEq((k,v) -> k.indexOf("a") >= 0, {id:1,name:"老王",age:null})--->name = '老王' and age is null -
例2:
allEq((k,v) -> k.indexOf("a") >= 0, {id:1,name:"老王",age:null}, false)--->name = '老王'
eq
eq(R column, Object val)
eq(boolean condition, R column, Object val)
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等于 =
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例:
eq("name", "老王")--->name = '老王'
ne
ne(R column, Object val)
ne(boolean condition, R column, Object val)
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不等于 <>
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例:
ne("name", "老王")--->name <> '老王'
gt
gt(R column, Object val)
gt(boolean condition, R column, Object val)
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大于 >
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例:
gt("age", 18)--->age > 18
ge
ge(R column, Object val)
ge(boolean condition, R column, Object val)
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大于等于 >=
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例:
ge("age", 18)--->age >= 18
lt
lt(R column, Object val)
lt(boolean condition, R column, Object val)
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小于 <
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例:
lt("age", 18)--->age < 18
le
le(R column, Object val)
le(boolean condition, R column, Object val)
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小于等于 <=
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例:
le("age", 18)--->age <= 18
between
between(R column, Object val1, Object val2)
between(boolean condition, R column, Object val1, Object val2)
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BETWEEN 值1 AND 值2
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例:
between("age", 18, 30)--->age between 18 and 30
notBetween
notBetween(R column, Object val1, Object val2)
notBetween(boolean condition, R column, Object val1, Object val2)
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NOT BETWEEN 值1 AND 值2
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例:
notBetween("age", 18, 30)--->age not between 18 and 30
like
like(R column, Object val)
like(boolean condition, R column, Object val)
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LIKE '%值%'
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例:
like("name", "王")--->name like '%王%'
notLike
notLike(R column, Object val)
notLike(boolean condition, R column, Object val)
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NOT LIKE '%值%'
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例:
notLike("name", "王")--->name not like '%王%'
likeLeft
likeLeft(R column, Object val)
likeLeft(boolean condition, R column, Object val)
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LIKE '%值'
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例:
likeLeft("name", "王")--->name like '%王'
likeRight
likeRight(R column, Object val)
likeRight(boolean condition, R column, Object val)
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LIKE '值%'
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例:
likeRight("name", "王")--->name like '王%'
isNull
isNull(R column)
isNull(boolean condition, R column)
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字段 IS NULL
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例:
isNull("name")--->name is null
isNotNull
isNotNull(R column)
isNotNull(boolean condition, R column)
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字段 IS NOT NULL
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例:
isNotNull("name")--->name is not null
in
in(R column, Collection value)
in(boolean condition, R column, Collection value)
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字段 IN (value.get(0), value.get(1), ...)
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例:
in("age",{1,2,3})--->age in (1,2,3)
in(R column, Object... values)
in(boolean condition, R column, Object... values)
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字段 IN (v0, v1, ...)
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例:
in("age", 1, 2, 3)--->age in (1,2,3)
notIn
notIn(R column, Collection value)
notIn(boolean condition, R column, Collection value)
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字段 IN (value.get(0), value.get(1), ...)
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例:
notIn("age",{1,2,3})--->age not in (1,2,3)
notIn(R column, Object... values)
notIn(boolean condition, R column, Object... values)
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字段 NOT IN (v0, v1, ...)
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例:
notIn("age", 1, 2, 3)--->age not in (1,2,3)
inSql
inSql(R column, String inValue)
inSql(boolean condition, R column, String inValue)
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字段 IN ( sql语句 )
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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)
notInSql
notInSql(R column, String inValue)
notInSql(boolean condition, R column, String inValue)
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字段 NOT IN ( sql语句 )
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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")--->age not in (select id from table where id < 3)
groupBy
groupBy(R... columns)
groupBy(boolean condition, R... columns)
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分组：GROUP BY 字段, ...
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例:
groupBy("id", "name")--->group by id,name
orderByAsc
orderByAsc(R... columns)
orderByAsc(boolean condition, R... columns)
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排序：ORDER BY 字段, ... ASC
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例:
orderByAsc("id", "name")--->order by id ASC,name ASC
orderByDesc
orderByDesc(R... columns)
orderByDesc(boolean condition, R... columns)
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排序：ORDER BY 字段, ... DESC
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例:
orderByDesc("id", "name")--->order by id DESC,name DESC
orderBy
orderBy(boolean condition, boolean isAsc, R... columns)
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排序：ORDER BY 字段, ...
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例:
orderBy(true, true, "id", "name")--->order by id ASC,name ASC
having
having(String sqlHaving, Object... params)
having(boolean condition, String sqlHaving, Object... params)
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HAVING ( sql语句 )
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例:
having("sum(age) > 10")--->having sum(age) > 10 -
例:
having("sum(age) > {0}", 11)--->having sum(age) > 11
or
or()
or(boolean condition)
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拼接 OR
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)
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例:
eq("id",1).or().eq("name","老王")--->id = 1 or name = '老王'
or(Function<Param, Param> func)
or(boolean condition, Function<Param, Param> func)
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OR 嵌套
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例:
or(i -> i.eq("name", "李白").ne("status", "活着"))--->or (name = '李白' and status <> '活着')
and
and(Function<Param, Param> func)
and(boolean condition, Function<Param, Param> func)
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AND 嵌套
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例:
and(i -> i.eq("name", "李白").ne("status", "活着"))--->and (name = '李白' and status <> '活着')
nested
nested(Function<Param, Param> func)
nested(boolean condition, Function<Param, Param> func)
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正常嵌套 不带 AND 或者 OR
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例:
nested(i -> i.eq("name", "李白").ne("status", "活着"))--->(name = '李白' and status <> '活着')
apply
apply(String applySql, Object... params)
apply(boolean condition, String applySql, Object... params)
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拼接 sql
注意事项:
该方法可用于数据库函数 动态入参的params对应前面applySql内部的{index}部分.这样是不会有sql注入风险的,反之会有!
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例:
apply("id = 1")--->id = 1 -
例:
apply("date_format(dateColumn,'%Y-%m-%d') = '2008-08-08'")--->date_format(dateColumn,'%Y-%m-%d') = '2008-08-08'") -
例:
apply("date_format(dateColumn,'%Y-%m-%d') = {0}", "2008-08-08")--->date_format(dateColumn,'%Y-%m-%d') = '2008-08-08'")
last
last(String lastSql)
last(boolean condition, String lastSql)
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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
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例:
last("limit 1")
exists
exists(String existsSql)
exists(boolean condition, String existsSql)
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拼接 EXISTS ( sql语句 )
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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)
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拼接 NOT EXISTS ( sql语句 )
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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
select
select(String... sqlSelect)
select(Predicate<TableFieldInfo> predicate)
select(Class<T> entityClass, Predicate<TableFieldInfo> predicate)
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设置查询字段
说明:
以上方分法为两类. 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
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例:
select("id", "name", "age") -
例:
select(i -> i.getProperty().startsWith("test"))
excludeColumns
@Deprecated
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排除查询字段
已从3.0.5版本上移除此方法!
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!
set
set(String column, Object val)
set(boolean condition, String column, Object val)
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SQL SET 字段
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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
setSql
setSql(String sql)
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设置 SET 部分 SQL
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例:
setSql("name = '老李头'")
lambda
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获取
LambdaWrapper在QueryWrapper中是获取LambdaQueryWrapper在UpdateWrapper中是获取LambdaUpdateWrapper
使用 Wrapper 自定义SQL
需求来源:
在使用了mybatis-plus之后, 自定义SQL的同时也想使用Wrapper的便利应该怎么办？ 在mybatis-plus版本3.0.7得到了完美解决 版本需要大于或等于3.0.7, 以下两种方案取其一即可
Service.java
mysqlMapper.getAll(Wrappers.<MysqlData>lambdaQuery().eq(MysqlData::getGroup, 1));
方案一 注解方式 Mapper.java
方案二 XML形式 Mapper.xml
<select id="getAll" resultType="MysqlData">
SELECT * FROM mysql_data ${ew.customSqlSegment}
select>
代码演示
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pom.xml
org.springframework.boot spring-boot-starter com.baomidou mybatis-plus-boot-starter 3.2.0 org.projectlombok lombok com.h2database h2 runtime org.springframework.boot spring-boot-starter-test test -
application.yml
# DataSource Config spring: datasource: driver-class-name: org.h2.Driver url: jdbc:h2:tcp://192.168.180.115:19200/~/mem/test username: root password: test # Logger Config logging: level: com.mp.wrapper: debug
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实体类
@Data public class Role { private Long id; private String roleName; private String roleDescribe; } @Data public class User { private Long id; private String name; private Integer age; private String email; private Long roleId; }
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Mapper
public interface RoleMapper extends BaseMapper
{ } public interface UserMapper extends BaseMapper { } -
启动类
@SpringBootApplication @MapperScan("com.mp.wrapper.mapper") public class WrapperApplication { public static void main(String[] args) { SpringApplication.run(WrapperApplication.class, args); } }
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数据库脚本
DROP TABLE IF EXISTS user; DROP TABLE IF EXISTS role; CREATE TABLE user ( id BIGINT (20) NOT NULL COMMENT '主键ID', name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名', age INT (11) NULL DEFAULT NULL COMMENT '年龄', email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱', role_id BIGINT (20) NOT NULL COMMENT '角色ID', PRIMARY KEY (id) ); CREATE TABLE role ( id BIGINT (20) NOT NULL COMMENT '主键ID', role_name VARCHAR(30) NULL DEFAULT NULL COMMENT '角色名', role_describe VARCHAR(30) NULL DEFAULT NULL COMMENT '角色描述', PRIMARY KEY (id) ); DELETE FROM user; DELETE FROM role; INSERT INTO role (id, role_name, role_describe) VALUES (1, '管理员', 'boos 级别'), (2, '用户', '就是个普通人'), (3, '程序猿', '偶尔需要用来祭天'); INSERT INTO user (id, name, age, email, role_id) VALUES (1, 'Jone', 18, '[email protected]', 1), (2, 'Jack', 20, '[email protected]', 2), (3, 'Tom', 28, '[email protected]', 2), (4, 'Sandy', 21, '[email protected]', 3), (5, 'Billie', 24, '[email protected]', 3);
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测试类
@SpringBootTest @RunWith(SpringRunner.class) class WrapperApplicationTests { @Resource private UserMapper userMapper; @Resource private RoleMapper roleMapper; @Test public void tests() { System.out.println("----- 普通查询 ------"); //SELECT id,role_id,name,email,age FROM user WHERE (role_id = ?) List
plainUsers = userMapper.selectList(new QueryWrapper ().eq("role_id", 2L)); List lambdaUsers = userMapper.selectList(new QueryWrapper ().lambda().eq(User::getRoleId, 2L)); Assert.assertEquals(plainUsers.size(), lambdaUsers.size()); print(plainUsers); System.out.println("----- 带子查询(sql注入) ------"); //SELECT id,role_id,name,email,age FROM user WHERE (role_id IN (select id from role where id = 2)) List plainUsers2 = userMapper.selectList(new QueryWrapper ().eq("1","1") .inSql("role_id", "select id from role where id = 2")); List lambdaUsers2 = userMapper.selectList(new QueryWrapper ().lambda() .inSql(User::getRoleId, "select id from role where id = 2")); Assert.assertEquals(plainUsers2.size(), lambdaUsers2.size()); print(plainUsers2); System.out.println("----- 带嵌套查询 ------"); //SELECT id,role_id,name,email,age FROM user WHERE ( (role_id = ? OR role_id = ?) ) AND ( (age >= ?) ) List plainUsers3 = userMapper.selectList(new QueryWrapper () .nested(i -> i.eq("role_id", 2L).or().eq("role_id", 3L)) .and(i -> i.ge("age", 20))); List lambdaUsers3 = userMapper.selectList(new QueryWrapper ().lambda() .nested(i -> i.eq(User::getRoleId, 2L).or().eq(User::getRoleId, 3L)) .and(i -> i.ge(User::getAge, 20))); Assert.assertEquals(plainUsers3.size(), lambdaUsers3.size()); print(plainUsers3); System.out.println("----- 自定义(sql注入) ------"); // SELECT id,role_id,name,email,age FROM user WHERE (role_id = 2) List plainUsers4 = userMapper.selectList(new QueryWrapper () .apply("role_id = 2")); print(plainUsers4); //UPDATE user SET email=? WHERE (id = ?) UpdateWrapper uw = new UpdateWrapper<>(); uw.set("email", null); uw.eq("id", 4); userMapper.update(new User(), uw); User u4 = userMapper.selectById(4); Assert.assertNull(u4.getEmail()); } @Test public void lambdaQueryWrapper() { System.out.println("----- 普通查询 ------"); List plainUsers = userMapper.selectList(new LambdaQueryWrapper ().eq(User::getRoleId, 2L)); List lambdaUsers = userMapper.selectList(new QueryWrapper ().lambda().eq(User::getRoleId, 2L)); Assert.assertEquals(plainUsers.size(), lambdaUsers.size()); print(plainUsers); System.out.println("----- 带子查询(sql注入) ------"); List plainUsers2 = userMapper.selectList(new LambdaQueryWrapper () .inSql(User::getRoleId, "select id from role where id = 2")); List lambdaUsers2 = userMapper.selectList(new QueryWrapper ().lambda() .inSql(User::getRoleId, "select id from role where id = 2")); Assert.assertEquals(plainUsers2.size(), lambdaUsers2.size()); print(plainUsers2); System.out.println("----- 带嵌套查询 ------"); List plainUsers3 = userMapper.selectList(new LambdaQueryWrapper () .nested(i -> i.eq(User::getRoleId, 2L).or().eq(User::getRoleId, 3L)) .and(i -> i.ge(User::getAge, 20))); List lambdaUsers3 = userMapper.selectList(new QueryWrapper ().lambda() .nested(i -> i.eq(User::getRoleId, 2L).or().eq(User::getRoleId, 3L)) .and(i -> i.ge(User::getAge, 20))); Assert.assertEquals(plainUsers3.size(), lambdaUsers3.size()); print(plainUsers3); System.out.println("----- 自定义(sql注入) ------"); List plainUsers4 = userMapper.selectList(new QueryWrapper () .apply("role_id = 2")); print(plainUsers4); UpdateWrapper uw = new UpdateWrapper<>(); uw.set("email", null); uw.eq("id", 4); userMapper.update(new User(), uw); User u4 = userMapper.selectById(4); Assert.assertNull(u4.getEmail()); } private void print(List list) { if (!CollectionUtils.isEmpty(list)) { list.forEach(System.out::println); } } /** * SELECT id,name,age,email,role_id FROM user * WHERE ( 1 = 1 ) AND ( ( name = ? AND age = ? ) OR ( name = ? AND age = ? ) ) */ @Test public void testSql() { QueryWrapper w = new QueryWrapper<>(); w.and(i -> i.eq("1", 1)) .nested(i -> i.and(j -> j.eq("name", "a").eq("age", 2)) .or(j -> j.eq("name", "b").eq("age", 2))); userMapper.selectList(w); } }