SpringBoot整合MybatisPlus3.X之Wrapper(五)

本文轉載自查看原文 2019-10-30 14:29 1567 mybatisplus3.x

官方文檔說明:

以下出現的第一個入參boolean condition表示該條件是否加入最后生成的sql中
以下代碼塊內的多個方法均為從上往下補全個別boolean類型的入參,默認為true
以下出現的泛型Param均為Wrapper的子類實例(均具有AbstractWrapper的所有方法)
以下方法在入參中出現的R為泛型,在普通wrapper中是String,在LambdaWrapper中是函數(例:Entity::getId,Entity為實體類,getId為字段id的getMethod)
以下方法入參中的R column均表示數據庫字段,當R具體類型為String時則為數據庫字段名(字段名是數據庫關鍵字的自己用轉義符包裹!)!而不是實體類數據字段名!!!,另當R具體類型為SFunction時項目runtime不支持eclipse自家的編譯器!!!
以下舉例均為使用普通wrapper,入參為Map和List的均以json形式表現!
使用中如果入參的Map或者List為空,則不會加入最后生成的sql中!!!

警告:

不支持以及不贊成在 RPC 調用中把 Wrapper 進行傳輸

wrapper 很重
傳輸 wrapper 可以類比為你的 controller 用 map 接收值(開發一時爽,維護火葬場)
正確的 RPC 調用姿勢是寫一個 DTO 進行傳輸,被調用方再根據 DTO 執行相應的操作
我們拒絕接受任何關於 RPC 傳輸 Wrapper 報錯相關的 issue 甚至 pr

AbstractWrapper

說明:

QueryWrapper(LambdaQueryWrapper) 和 UpdateWrapper(LambdaUpdateWrapper) 的父類用於生成 sql 的 where 條件, entity 屬性也用於生成 sql 的 where 條件注意: entity 生成的 where 條件與使用各個 api 生成的 where 條件沒有任何關聯行為

allEq

allEq(Map<R, V> params)
allEq(Map<R, V> params, boolean null2IsNull)
allEq(boolean condition, Map<R, V> params, boolean null2IsNull)

全部eq(或個別isNull)

個別參數說明:

params : key為數據庫字段名,value為字段值 null2IsNull : 為true則在map的value為null時調用 isNull 方法,為false時則忽略value為null的

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)

個別參數說明:

filter : 過濾函數,是否允許字段傳入比對條件中 params 與 null2IsNull : 同上

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)

等於 =
例: eq("name", "老王")--->name = '老王'

ne

ne(R column, Object val)
ne(boolean condition, R column, Object val)

不等於 <>
例: ne("name", "老王")--->name <> '老王'

gt

gt(R column, Object val)
gt(boolean condition, R column, Object val)

大於 >
例: gt("age", 18)--->age > 18

ge

ge(R column, Object val)
ge(boolean condition, R column, Object val)

大於等於 >=
例: ge("age", 18)--->age >= 18

lt

lt(R column, Object val)
lt(boolean condition, R column, Object val)

小於 <
例: lt("age", 18)--->age < 18

le

le(R column, Object val)
le(boolean condition, R column, Object val)

小於等於 <=
例: le("age", 18)--->age <= 18

between

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

notBetween

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

like

like(R column, Object val)
like(boolean condition, R column, Object val)

LIKE '%值%'
例: like("name", "王")--->name like '%王%'

notLike

notLike(R column, Object val)
notLike(boolean condition, R column, Object val)

NOT LIKE '%值%'
例: notLike("name", "王")--->name not like '%王%'

likeLeft

likeLeft(R column, Object val)
likeLeft(boolean condition, R column, Object val)

LIKE '%值'
例: likeLeft("name", "王")--->name like '%王'

likeRight

likeRight(R column, Object val)
likeRight(boolean condition, R column, Object val)

LIKE '值%'
例: likeRight("name", "王")--->name like '王%'

isNull

isNull(R column)
isNull(boolean condition, R column)

字段 IS NULL
例: isNull("name")--->name is null

isNotNull

isNotNull(R column)
isNotNull(boolean condition, R column)

字段 IS NOT NULL
例: isNotNull("name")--->name is not null

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)

notIn

notIn(R column, Collection<?> value)
notIn(boolean condition, R column, Collection<?> value)

字段 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)

inSql

inSql(R column, String inValue)
inSql(boolean condition, R column, String inValue)

字段 IN ( sql語句 )
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)

notInSql

notInSql(R column, String inValue)
notInSql(boolean condition, R column, String inValue)

字段 NOT IN ( sql語句 )
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")--->age not in (select id from table where id < 3)

groupBy

groupBy(R... columns)
groupBy(boolean condition, R... columns)

分組：GROUP BY 字段, ...
例: groupBy("id", "name")--->group by id,name

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

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

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

having

having(String sqlHaving, Object... params)
having(boolean condition, String sqlHaving, Object... params)

HAVING ( sql語句 )
例: having("sum(age) > 10")--->having sum(age) > 10
例: having("sum(age) > {0}", 11)--->having sum(age) > 11

or

or()
or(boolean condition)

拼接 OR

注意事項:

主動調用or表示緊接着下一個方法不是用and連接!(不調用or則默認為使用and連接)

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)

OR 嵌套
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)

AND 嵌套
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)

正常嵌套不帶 AND 或者 OR
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)

拼接 sql

注意事項:

該方法可用於數據庫函數動態入參的params對應前面applySql內部的{index}部分.這樣是不會有sql注入風險的,反之會有!

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)

無視優化規則直接拼接到 sql 的最后

注意事項:

只能調用一次,多次調用以最后一次為准有sql注入的風險,請謹慎使用

例: last("limit 1")

exists

exists(String existsSql)
exists(boolean condition, String existsSql)

拼接 EXISTS ( sql語句 )
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)

拼接 NOT EXISTS ( sql語句 )
例: notExists("select id from table where age = 1")--->not exists (select id from table where age = 1)

QueryWrapper

說明:

繼承自 AbstractWrapper ,自身的內部屬性 entity 也用於生成 where 條件及 LambdaQueryWrapper, 可以通過 new QueryWrapper().lambda() 方法獲取

select

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

設置查詢字段

說明:

以上方分法為兩類. 第二類方法為:過濾查詢字段(主鍵除外),入參不包含 class 的調用前需要wrapper內的entity屬性有值! 這兩類方法重復調用以最后一次為准

例: select("id", "name", "age")
例: select(i -> i.getProperty().startsWith("test"))

excludeColumns

@Deprecated

排除查詢字段

已從3.0.5版本上移除此方法!

UpdateWrapper

說明:

繼承自 AbstractWrapper ,自身的內部屬性 entity 也用於生成 where 條件及 LambdaUpdateWrapper, 可以通過 new UpdateWrapper().lambda() 方法獲取!

set

set(String column, Object val)
set(boolean condition, String column, Object val)

SQL SET 字段
例: set("name", "老李頭")
例: set("name", "")--->數據庫字段值變為空字符串
例: set("name", null)--->數據庫字段值變為null

setSql

setSql(String sql)

設置 SET 部分 SQL
例: setSql("name = '老李頭'")

lambda

獲取 LambdaWrapper 在QueryWrapper中是獲取LambdaQueryWrapper 在UpdateWrapper中是獲取LambdaUpdateWrapper

使用 Wrapper 自定義SQL

需求來源:

在使用了mybatis-plus之后, 自定義SQL的同時也想使用Wrapper的便利應該怎么辦？在mybatis-plus版本3.0.7得到了完美解決版本需要大於或等於3.0.7, 以下兩種方案取其一即可

Service.java

mysqlMapper.getAll(Wrappers.<MysqlData>lambdaQuery().eq(MysqlData::getGroup, 1));

方案一注解方式 Mapper.java

@Select("select * from mysql_data ${ew.customSqlSegment}")
List<MysqlData> getAll(@Param(Constants.WRAPPER) Wrapper wrapper);

方案二 XML形式 Mapper.xml

<select id="getAll" resultType="MysqlData">
 SELECT * FROM mysql_data ${ew.customSqlSegment}
</select>

代碼演示

pom.xml

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- for testing -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

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

實體類

@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;
}

Mapper

public interface RoleMapper extends BaseMapper<Role> {
}
public interface UserMapper extends BaseMapper<User> {
}

啟動類

@SpringBootApplication
@MapperScan("com.mp.wrapper.mapper")
public class WrapperApplication {

    public static void main(String[] args) {
        SpringApplication.run(WrapperApplication.class, args);
    }

}

數據庫腳本

DROP TABLE IF EXISTS user;
DROP TABLE IF EXISTS role;

CREATE TABLE user
(
  id      BIGINT (20) NOT NULL COMMENT '主鍵ID',
  name    VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
  age     INT (11) NULL DEFAULT NULL COMMENT '年齡',
  email   VARCHAR(50) NULL DEFAULT NULL COMMENT '郵箱',
  role_id BIGINT (20) NOT NULL COMMENT '角色ID',
  PRIMARY KEY (id)
);

CREATE TABLE role
(
  id            BIGINT (20) NOT NULL COMMENT '主鍵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, '管理員', 'boos 級別'),
       (2, '用戶', '就是個普通人'),
       (3, '程序猿', '偶爾需要用來祭天');

INSERT INTO user (id, name, age, email, role_id)
VALUES (1, 'Jone', 18, 'test1@baomidou.com', 1),
       (2, 'Jack', 20, 'test2@baomidou.com', 2),
       (3, 'Tom', 28, 'test3@baomidou.com', 2),
       (4, 'Sandy', 21, 'test4@baomidou.com', 3),
       (5, 'Billie', 24, 'test5@baomidou.com', 3);

測試類

@SpringBootTest
@RunWith(SpringRunner.class)
class WrapperApplicationTests {

    @Resource
    private UserMapper userMapper;
    @Resource
    private RoleMapper roleMapper;

    @Test
    public void tests() {
        System.out.println("----- 普通查詢 ------");
        //SELECT id,role_id,name,email,age FROM user WHERE (role_id = ?)
        List<User> plainUsers = userMapper.selectList(new QueryWrapper<User>().eq("role_id", 2L));
        List<User> lambdaUsers = userMapper.selectList(new QueryWrapper<User>().lambda().eq(User::getRoleId, 2L));
        Assert.assertEquals(plainUsers.size(), lambdaUsers.size());
        print(plainUsers);

        System.out.println("----- 帶子查詢(sql注入) ------");
        //SELECT id,role_id,name,email,age FROM user WHERE (role_id IN (select id from role where id = 2))
        List<User> plainUsers2 = userMapper.selectList(new QueryWrapper<User>().eq("1","1")
                .inSql("role_id", "select id from role where id = 2"));
        List<User> lambdaUsers2 = userMapper.selectList(new QueryWrapper<User>().lambda()
                .inSql(User::getRoleId, "select id from role where id = 2"));
        Assert.assertEquals(plainUsers2.size(), lambdaUsers2.size());
        print(plainUsers2);

        System.out.println("----- 帶嵌套查詢 ------");
        //SELECT id,role_id,name,email,age FROM user WHERE ( (role_id = ? OR role_id = ?) ) AND ( (age >= ?) )
        List<User> plainUsers3 = userMapper.selectList(new QueryWrapper<User>()
                .nested(i -> i.eq("role_id", 2L).or().eq("role_id", 3L))
                .and(i -> i.ge("age", 20)));
        List<User> lambdaUsers3 = userMapper.selectList(new QueryWrapper<User>().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("----- 自定義(sql注入) ------");
        // SELECT id,role_id,name,email,age FROM user WHERE (role_id = 2)
        List<User> plainUsers4 = userMapper.selectList(new QueryWrapper<User>()
                .apply("role_id = 2"));
        print(plainUsers4);

        //UPDATE user SET email=? WHERE (id = ?)
        UpdateWrapper<User> 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("----- 普通查詢 ------");
        List<User> plainUsers = userMapper.selectList(new LambdaQueryWrapper<User>().eq(User::getRoleId, 2L));
        List<User> lambdaUsers = userMapper.selectList(new QueryWrapper<User>().lambda().eq(User::getRoleId, 2L));
        Assert.assertEquals(plainUsers.size(), lambdaUsers.size());
        print(plainUsers);

        System.out.println("----- 帶子查詢(sql注入) ------");
        List<User> plainUsers2 = userMapper.selectList(new LambdaQueryWrapper<User>()
                .inSql(User::getRoleId, "select id from role where id = 2"));
        List<User> lambdaUsers2 = userMapper.selectList(new QueryWrapper<User>().lambda()
                .inSql(User::getRoleId, "select id from role where id = 2"));
        Assert.assertEquals(plainUsers2.size(), lambdaUsers2.size());
        print(plainUsers2);

        System.out.println("----- 帶嵌套查詢 ------");
        List<User> plainUsers3 = userMapper.selectList(new LambdaQueryWrapper<User>()
                .nested(i -> i.eq(User::getRoleId, 2L).or().eq(User::getRoleId, 3L))
                .and(i -> i.ge(User::getAge, 20)));
        List<User> lambdaUsers3 = userMapper.selectList(new QueryWrapper<User>().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("----- 自定義(sql注入) ------");
        List<User> plainUsers4 = userMapper.selectList(new QueryWrapper<User>()
                .apply("role_id = 2"));
        print(plainUsers4);

        UpdateWrapper<User> 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 <T> void print(List<T> 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<User> 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);
    }
}

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猜您在找 SpringBoot整合MybatisPlus3.X之邏輯刪除(三) SpringBoot整合Mybatisplus3.x之CRUD(一) SpringBoot整合MybatisPlus3.X之Sequence(二) SpringBoot與MybatisPlus3.X整合示例(十六) SpringBoot整合MybatisPlus3.X之SQL注入器(九) SpringBoot整合MybatisPlus3.X之樂觀鎖(十三) SpringBoot整合MybatisPlus3.X之自定義Mapper(十) SpringBoot整合MybatisPlus3.X之SQL執行分析插件(十四) SpringBoot與MybatisPlus3.X整合之字段類型處理器(八) SpringBoot與MybatisPlus3.X整合之通用枚舉(十二)

SpringBoot整合MybatisPlus3.X之Wrapper(五)

官方文檔說明:

AbstractWrapper

allEq

eq

ne

gt

ge

lt

le

between

notBetween

like

notLike

likeLeft

likeRight

isNull

isNotNull

in

notIn

inSql

notInSql

groupBy

orderByAsc

orderByDesc

orderBy

having

or

and

nested

apply

last

exists

notExists

QueryWrapper

select

excludeColumns

@Deprecated

UpdateWrapper

set

setSql

lambda

使用 Wrapper 自定義SQL

Service.java

方案一 注解方式 Mapper.java

方案二 XML形式 Mapper.xml

代碼演示

免責聲明！

方案一注解方式 Mapper.java