mirror of
https://gitee.com/best_handsome/mybatis-plus-join
synced 2025-07-11 00:02:22 +08:00
update
This commit is contained in:
parent
b87aa2789a
commit
eb1f3347f6
92
README.md
92
README.md
@ -10,6 +10,8 @@
|
||||
|
||||
## 使用方法
|
||||
|
||||
### 方法一
|
||||
|
||||
1. 将代码down到本地,使用maven install
|
||||
|
||||
2. 在自己的项目中替换mybatisplus依赖(框架依赖mybatisplus<3.4.2>)
|
||||
@ -21,9 +23,16 @@
|
||||
<version>1.0-SNAPSHOT</version>
|
||||
</dependency>
|
||||
```
|
||||
|
||||
### 方法二
|
||||
|
||||
1. 将mybatisplus目录复制到你的工程中
|
||||
|
||||
2. 如果mybatisplus目录不在springboot扫描路径下,
|
||||
将MybatisPlusConfiguration移动到springboot扫描路径下或添加springboot扫描路径
|
||||
|
||||
### 使用
|
||||
|
||||
* entity继承MyBaseEntity (需要连表的实体类必须继承,其他可以不继承)
|
||||
* mapper继承MyBaseMapper (必选)
|
||||
* service继承MyBaseService (可选)
|
||||
* serviceImpl继承MyBaseServiceImpl (可选)
|
||||
@ -38,12 +47,14 @@
|
||||
class test {
|
||||
@Resource
|
||||
private UserMapper userMapper;
|
||||
|
||||
|
||||
void testJoin() {
|
||||
List<UserDTO> list = userMapper.selectJoinList(new MyLambdaQueryWrapper<UserEntity>()
|
||||
.select(UserEntity::getHeadImg, UserEntity::getName)
|
||||
.leftJoin(UserEntity::getId, UserAddressEntity::getUserId,
|
||||
right -> right.select(UserAddressEntity::getAddress, UserAddressEntity::getTel))
|
||||
.selectAll(UserEntity.class)
|
||||
.leftJoin(UserEntity::getId, UserAddressEntity::getUserId, r1 -> r1
|
||||
.select(UserAddressEntity::getAddress)
|
||||
.leftJoin(UserAddressEntity::getAreaId, AreaEntity::getId,
|
||||
r2 -> r2.select(AreaEntity::getProvince)))
|
||||
, UserDTO.class);
|
||||
}
|
||||
}
|
||||
@ -52,14 +63,15 @@ class test {
|
||||
对应sql
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
t0.head_img,
|
||||
t0.name,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM
|
||||
user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
SELECT t0.name,
|
||||
t0.sex,
|
||||
t0.head_img,
|
||||
t0.id,
|
||||
t1.address,
|
||||
t2.province
|
||||
FROM user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
LEFT JOIN area t2 ON t1.area_id = t2.id
|
||||
```
|
||||
|
||||
#### selectAll(UserEntity.class) 查询UserEntity全部字段
|
||||
@ -84,16 +96,14 @@ class test {
|
||||
对应sql
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
t0.name,
|
||||
t0.sex,
|
||||
t0.head_img,
|
||||
t0.id,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM
|
||||
user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
SELECT t0.name,
|
||||
t0.sex,
|
||||
t0.head_img,
|
||||
t0.id,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
```
|
||||
|
||||
#### as(UserEntity::getHeadImg,UserDTO::getUserHeadImg)
|
||||
@ -118,13 +128,11 @@ class test {
|
||||
对应sql
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
t0.head_img AS userHeadImg,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM
|
||||
user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
SELECT t0.head_img AS userHeadImg,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
```
|
||||
|
||||
#### 左连接 leftJoin(UserEntity::getId,UserAddressEntity::getUserId,right -> right)
|
||||
@ -156,20 +164,18 @@ class test {
|
||||
对应sql
|
||||
|
||||
```sql
|
||||
SELECT
|
||||
t0.name,
|
||||
t0.sex,
|
||||
t0.head_img,
|
||||
t0.id,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM
|
||||
user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
SELECT t0.name,
|
||||
t0.sex,
|
||||
t0.head_img,
|
||||
t0.id,
|
||||
t1.address,
|
||||
t1.tel
|
||||
FROM user t0
|
||||
LEFT JOIN user_address t1 ON t0.id = t1.user_id
|
||||
WHERE (
|
||||
t0.id = ?
|
||||
AND t1.tel LIKE ?
|
||||
AND t0.id = t1.user_id)
|
||||
t0.id = ?
|
||||
AND t1.tel LIKE ?
|
||||
AND t0.id = t1.user_id)
|
||||
```
|
||||
|
||||
#### [参考测试类](https://gitee.com/best_handsome/mybatis-plus-join/blob/master/src/test/java/com/example/mp/MpJoinTest.java)
|
||||
|
Loading…
x
Reference in New Issue
Block a user