MyBatis：條件構造器QueryWrapper方法詳解 MyBatis：條件構造器QueryWrapper方法詳解
阿新 • • 發佈：2022-04-04
MyBatis：條件構造器QueryWrapper方法詳解
目錄
- QueryWrapper
- 1. eq、ne
- 2. gt、ge、lt、le
- 3. between、notBetween
- 4. like、notLike、likeLeft、likeRight
- 5. isNull、isNotNull
- 6. in、notIn
- 7. or、and
- 8. orderByAsc、orderByDesc
- 9. inSql、notInSql (不常用)
- 10. exists、notExists (不常用)
正文
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.
測試用表：
回到頂部1. eq、ne
說明：
eq：等於，ne：不等於
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> wrapper = new QueryWrapper<>();
//eq() 等於
wrapper.eq("last_name", "皮皮蝦");
Employee one = employeeService.getOne(wrapper);
System.out.println(one);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> wrapper = new QueryWrapper<>();
//ne() 不等於
wrapper.ne("gender", 0);
List<Employee> list = employeeService.list(wrapper);
System.out.println(list);
}
回到頂部
2. gt、ge、lt、le
說明：
gt：大於，ge：大於等於，lt：小於，le：小於等於
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> gtWrapper = new QueryWrapper<>();
//gt() 大於
gtWrapper.gt("age", 27);
List<Employee> gtList = employeeService.list(gtWrapper);
System.out.println(gtList);
//**********************
QueryWrapper<Employee> geWrapper = new QueryWrapper<>();
//ge() 大於等於
geWrapper.ge("age", 26);
List<Employee> geList = employeeService.list(geWrapper);
System.out.println(geList);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> ltWrapper = new QueryWrapper<>();
//lt() 小於
ltWrapper.lt("age", 12);
List<Employee> ltList = employeeService.list(ltWrapper);
System.out.println(ltList);
//**********************
QueryWrapper<Employee> geWrapper = new QueryWrapper<>();
//le() 小於等於
leWrapper.le("age", 12);
List<Employee> leList = employeeService.list(leWrapper);
System.out.println(leList);
}
回到頂部
3. between、notBetween
說明：
between：在值1和值2之間，notBetween：不在值1和值2之間
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> betweenWrapper = new QueryWrapper<>();
//between() 區間的值
betweenWrapper.between("age", 10, 20);
List<Employee> betweenList = employeeService.list(betweenWrapper);
System.out.println(betweenList );
//**********************
QueryWrapper<Employee> notBetweenWrapper = new QueryWrapper<>();
//notBetween() 不在區間的值
notBetweenWrapper.notBetween("age", 10, 21);
List<Employee> notBetweenList = employeeService.list(notBetweenWrapper );
System.out.println(notBetweenList );
}
回到頂部
4. like、notLike、likeLeft、likeRight
說明：
like：’%值%’，notLike：’%值%’，likeLeft：’%值’，likeRight：'值%'
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> likeWrapper = new QueryWrapper<>();
//like() 模糊查詢匹配值
likeWrapper.like("last_name", "s");
List<Employee> likeList = employeeService.list(likeWrapper);
System.out.println(likeList );
//**********************
QueryWrapper<Employee> notLikeWrapper = new QueryWrapper<>();
//notLike() 模糊查詢不匹配值
notLikeWrapper.notLike("last_name", "s");
List<Employee> notLikeList = employeeService.list(notLikeWrapper);
System.out.println(notLikeList);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> likeLeftWrapper = new QueryWrapper<>();
//likeLeft() 模糊查詢匹配最後一位值
likeLeftWrapper.likeLeft("last_name", "s");
List<Employee> likeLeftList = employeeService.list(likeLeftWrapper);
System.out.println(likeLeftList );
//**********************
QueryWrapper<Employee> likeRightWrapper = new QueryWrapper<>();
//likeRight() 模糊查詢匹配第一位值
likeRightWrapper.likeRight("last_name", "s");
List<Employee> likeRightList = employeeService.list(likeRightWrapper );
System.out.println(likeRightList );
}
回到頂部
5. isNull、isNotNull
說明：
isNull：欄位 IS NULL，isNotNull：欄位 IS NOT NULL
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> isNullWrapper = new QueryWrapper<>();
//isNull() 為空
isNullWrapper.isNull("email");
List<Employee> isNullList = employeeService.list(isNullWrapper);
System.out.println(isNullList );
//**********************
QueryWrapper<Employee> isNotNullWrapper = new QueryWrapper<>();
//isNotNull() 不為空
isNotNullWrapper.isNotNull("last_name", "s");
List<Employee> isNotNullList = employeeService.list(isNotNullWrapper );
System.out.println(isNotNullList );
}
回到頂部
6. in、notIn
說明：
in：欄位 IN (v0, v1, …)，notIn：欄位 NOT IN (value.get(0), value.get(1), …)
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> inWrapper = new QueryWrapper<>();
//in() 符合多個條件的值
inWrapper.in("age", 8, 16, 26);
List<Employee> inList = employeeService.list(inWrapper);
System.out.println(inList );
//**********************
QueryWrapper<Employee> notInWrapper= new QueryWrapper<>();
//notIn() 不符合多個條件的值
notInWrapper.notIn("age", 8, 16, 26);
List<Employee> notInList = employeeService.list(notInWrapper);
System.out.println(notInList );
}
回到頂部
7. or、and
說明：
or：或者 ，and：和
注意事項:
主動呼叫or表示緊接著下一個方法不是用and連線!(不呼叫or則預設為使用and連線)
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> orWrapper = new QueryWrapper<>();
//or() 查詢age大於20 或者 gender等於1 的資料
orWrapper.gt("age", 20).or().eq("gender", 1);
List<Employee> orList = employeeService.list(orWrapper);
System.out.println(orList );
}
@Test
public void contextLoads(){
QueryWrapper<Employee> andWrapper = new QueryWrapper<>();
//and() 查詢last_name等於皮皮蝦b 和 gender等於1 的資料 (不使用and() 預設就是and())
andWrapper.eq("last_name", "皮皮蝦b").eq("gender", 1);
List<Employee> andList = employeeService.list(andWrapper );
System.out.println(andList);
}
回到頂部
8. orderByAsc、orderByDesc
說明：
orderByAsc：升序：ORDER BY 欄位, … ASC，orderByDesc：降序：ORDER BY 欄位, … DESC
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> Wrapper = new QueryWrapper<>();
//orderByAsc() 升序排序
Wrapper.orderByAsc("id");
List<Employee> list = employeeService.list(Wrapper);
for(Employee e : list) {
System.out.println(e);
}
}
@Test
public void contextLoads(){
QueryWrapper<Employee> Wrapper = new QueryWrapper<>();
//orderByDesc() 降序排序
Wrapper.orderByDesc("id");
List<Employee> list = employeeService.list(Wrapper);
for(Employee e : list) {
System.out.println(e);
}
}
回到頂部
9. inSql、notInSql (不常用)
說明：
inSql：欄位 IN ( sql語句 )，notInSql：欄位 NOT IN ( sql語句 )
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> inSqlWrapper = new QueryWrapper<>();
//inSql() 符合sql語句的值
inSqlWrapper .inSql("select id from employee where id < 10");
List<Employee> inSqlList = employeeService.list(inSqlWrapper );
System.out.println(inSqlList );
//**********************
QueryWrapper<Employee> notInSqlWrapper= new QueryWrapper<>();
//notInSql() 不符合sql語句的值
notInSqlWrapper.notInSql("select id from employee where id < 10");
List<Employee> notInSqlList = employeeService.list(notInSqlWrapper);
System.out.println(notInSqlList );
}
回到頂部
10. exists、notExists (不常用)
說明：
exists：拼接 EXISTS ( sql語句 )，notExists：拼接 NOT EXISTS ( sql語句 )
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> existsWrapper = new QueryWrapper<>();
//exists() 查詢符合sql語句的值
existsWrapper.exists("select last_name,gender from employee where id = 1");
List<Employee> existsList = employeeService.list(existsWrapper);
System.out.println(existsList );
//**********************
QueryWrapper<Employee> notExistsWrapper = new QueryWrapper<>();
//notExists() 查詢不符合sql語句的值
notExistsWrapper.notExists("select last_name,gender from employee where id = 1");
List<Employee> notExistsList = employeeService.list(notExistsWrapper);
System.out.println(notExistsList );
}
目錄
- QueryWrapper
- 1. eq、ne
- 2. gt、ge、lt、le
- 3. between、notBetween
- 4. like、notLike、likeLeft、likeRight
- 5. isNull、isNotNull
- 6. in、notIn
- 7. or、and
- 8. orderByAsc、orderByDesc
- 9. inSql、notInSql (不常用)
- 10. exists、notExists (不常用)
正文
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.
測試用表：
回到頂部1. eq、ne
說明：
eq：等於，ne：不等於
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> wrapper = new QueryWrapper<>();
//eq() 等於
wrapper.eq("last_name", "皮皮蝦");
Employee one = employeeService.getOne(wrapper);
System.out.println(one);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> wrapper = new QueryWrapper<>();
//ne() 不等於
wrapper.ne("gender", 0);
List<Employee> list = employeeService.list(wrapper);
System.out.println(list);
}
回到頂部
2. gt、ge、lt、le
說明：
gt：大於，ge：大於等於，lt：小於，le：小於等於
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> gtWrapper = new QueryWrapper<>();
//gt() 大於
gtWrapper.gt("age", 27);
List<Employee> gtList = employeeService.list(gtWrapper);
System.out.println(gtList);
//**********************
QueryWrapper<Employee> geWrapper = new QueryWrapper<>();
//ge() 大於等於
geWrapper.ge("age", 26);
List<Employee> geList = employeeService.list(geWrapper);
System.out.println(geList);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> ltWrapper = new QueryWrapper<>();
//lt() 小於
ltWrapper.lt("age", 12);
List<Employee> ltList = employeeService.list(ltWrapper);
System.out.println(ltList);
//**********************
QueryWrapper<Employee> geWrapper = new QueryWrapper<>();
//le() 小於等於
leWrapper.le("age", 12);
List<Employee> leList = employeeService.list(leWrapper);
System.out.println(leList);
}
回到頂部
3. between、notBetween
說明：
between：在值1和值2之間，notBetween：不在值1和值2之間
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> betweenWrapper = new QueryWrapper<>();
//between() 區間的值
betweenWrapper.between("age", 10, 20);
List<Employee> betweenList = employeeService.list(betweenWrapper);
System.out.println(betweenList );
//**********************
QueryWrapper<Employee> notBetweenWrapper = new QueryWrapper<>();
//notBetween() 不在區間的值
notBetweenWrapper.notBetween("age", 10, 21);
List<Employee> notBetweenList = employeeService.list(notBetweenWrapper );
System.out.println(notBetweenList );
}
回到頂部
4. like、notLike、likeLeft、likeRight
說明：
like：’%值%’，notLike：’%值%’，likeLeft：’%值’，likeRight：'值%'
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> likeWrapper = new QueryWrapper<>();
//like() 模糊查詢匹配值
likeWrapper.like("last_name", "s");
List<Employee> likeList = employeeService.list(likeWrapper);
System.out.println(likeList );
//**********************
QueryWrapper<Employee> notLikeWrapper = new QueryWrapper<>();
//notLike() 模糊查詢不匹配值
notLikeWrapper.notLike("last_name", "s");
List<Employee> notLikeList = employeeService.list(notLikeWrapper);
System.out.println(notLikeList);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> likeLeftWrapper = new QueryWrapper<>();
//likeLeft() 模糊查詢匹配最後一位值
likeLeftWrapper.likeLeft("last_name", "s");
List<Employee> likeLeftList = employeeService.list(likeLeftWrapper);
System.out.println(likeLeftList );
//**********************
QueryWrapper<Employee> likeRightWrapper = new QueryWrapper<>();
//likeRight() 模糊查詢匹配第一位值
likeRightWrapper.likeRight("last_name", "s");
List<Employee> likeRightList = employeeService.list(likeRightWrapper );
System.out.println(likeRightList );
}
回到頂部
5. isNull、isNotNull
說明：
isNull：欄位 IS NULL，isNotNull：欄位 IS NOT NULL
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> isNullWrapper = new QueryWrapper<>();
//isNull() 為空
isNullWrapper.isNull("email");
List<Employee> isNullList = employeeService.list(isNullWrapper);
System.out.println(isNullList );
//**********************
QueryWrapper<Employee> isNotNullWrapper = new QueryWrapper<>();
//isNotNull() 不為空
isNotNullWrapper.isNotNull("last_name", "s");
List<Employee> isNotNullList = employeeService.list(isNotNullWrapper );
System.out.println(isNotNullList );
}
回到頂部
6. in、notIn
說明：
in：欄位 IN (v0, v1, …)，notIn：欄位 NOT IN (value.get(0), value.get(1), …)
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> inWrapper = new QueryWrapper<>();
//in() 符合多個條件的值
inWrapper.in("age", 8, 16, 26);
List<Employee> inList = employeeService.list(inWrapper);
System.out.println(inList );
//**********************
QueryWrapper<Employee> notInWrapper= new QueryWrapper<>();
//notIn() 不符合多個條件的值
notInWrapper.notIn("age", 8, 16, 26);
List<Employee> notInList = employeeService.list(notInWrapper);
System.out.println(notInList );
}
回到頂部
7. or、and
說明：
or：或者 ，and：和
注意事項:
主動呼叫or表示緊接著下一個方法不是用and連線!(不呼叫or則預設為使用and連線)
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> orWrapper = new QueryWrapper<>();
//or() 查詢age大於20 或者 gender等於1 的資料
orWrapper.gt("age", 20).or().eq("gender", 1);
List<Employee> orList = employeeService.list(orWrapper);
System.out.println(orList );
}
@Test
public void contextLoads(){
QueryWrapper<Employee> andWrapper = new QueryWrapper<>();
//and() 查詢last_name等於皮皮蝦b 和 gender等於1 的資料 (不使用and() 預設就是and())
andWrapper.eq("last_name", "皮皮蝦b").eq("gender", 1);
List<Employee> andList = employeeService.list(andWrapper );
System.out.println(andList);
}
回到頂部
8. orderByAsc、orderByDesc
說明：
orderByAsc：升序：ORDER BY 欄位, … ASC，orderByDesc：降序：ORDER BY 欄位, … DESC
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> Wrapper = new QueryWrapper<>();
//orderByAsc() 升序排序
Wrapper.orderByAsc("id");
List<Employee> list = employeeService.list(Wrapper);
for(Employee e : list) {
System.out.println(e);
}
}
@Test
public void contextLoads(){
QueryWrapper<Employee> Wrapper = new QueryWrapper<>();
//orderByDesc() 降序排序
Wrapper.orderByDesc("id");
List<Employee> list = employeeService.list(Wrapper);
for(Employee e : list) {
System.out.println(e);
}
}
回到頂部
9. inSql、notInSql (不常用)
說明：
inSql：欄位 IN ( sql語句 )，notInSql：欄位 NOT IN ( sql語句 )
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> inSqlWrapper = new QueryWrapper<>();
//inSql() 符合sql語句的值
inSqlWrapper .inSql("select id from employee where id < 10");
List<Employee> inSqlList = employeeService.list(inSqlWrapper );
System.out.println(inSqlList );
//**********************
QueryWrapper<Employee> notInSqlWrapper= new QueryWrapper<>();
//notInSql() 不符合sql語句的值
notInSqlWrapper.notInSql("select id from employee where id < 10");
List<Employee> notInSqlList = employeeService.list(notInSqlWrapper);
System.out.println(notInSqlList );
}
回到頂部
10. exists、notExists (不常用)
說明：
exists：拼接 EXISTS ( sql語句 )，notExists：拼接 NOT EXISTS ( sql語句 )
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> existsWrapper = new QueryWrapper<>();
//exists() 查詢符合sql語句的值
existsWrapper.exists("select last_name,gender from employee where id = 1");
List<Employee> existsList = employeeService.list(existsWrapper);
System.out.println(existsList );
//**********************
QueryWrapper<Employee> notExistsWrapper = new QueryWrapper<>();
//notExists() 查詢不符合sql語句的值
notExistsWrapper.notExists("select last_name,gender from employee where id = 1");
List<Employee> notExistsList = employeeService.list(notExistsWrapper);
System.out.println(notExistsList );
}
目錄
- QueryWrapper
- 1. eq、ne
- 2. gt、ge、lt、le
- 3. between、notBetween
- 4. like、notLike、likeLeft、likeRight
- 5. isNull、isNotNull
- 6. in、notIn
- 7. or、and
- 8. orderByAsc、orderByDesc
- 9. inSql、notInSql (不常用)
- 10. exists、notExists (不常用)
正文
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.
測試用表：
回到頂部1. eq、ne
說明：
eq：等於，ne：不等於
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> wrapper = new QueryWrapper<>();
//eq() 等於
wrapper.eq("last_name", "皮皮蝦");
Employee one = employeeService.getOne(wrapper);
System.out.println(one);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> wrapper = new QueryWrapper<>();
//ne() 不等於
wrapper.ne("gender", 0);
List<Employee> list = employeeService.list(wrapper);
System.out.println(list);
}
回到頂部
2. gt、ge、lt、le
說明：
gt：大於，ge：大於等於，lt：小於，le：小於等於
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> gtWrapper = new QueryWrapper<>();
//gt() 大於
gtWrapper.gt("age", 27);
List<Employee> gtList = employeeService.list(gtWrapper);
System.out.println(gtList);
//**********************
QueryWrapper<Employee> geWrapper = new QueryWrapper<>();
//ge() 大於等於
geWrapper.ge("age", 26);
List<Employee> geList = employeeService.list(geWrapper);
System.out.println(geList);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> ltWrapper = new QueryWrapper<>();
//lt() 小於
ltWrapper.lt("age", 12);
List<Employee> ltList = employeeService.list(ltWrapper);
System.out.println(ltList);
//**********************
QueryWrapper<Employee> geWrapper = new QueryWrapper<>();
//le() 小於等於
leWrapper.le("age", 12);
List<Employee> leList = employeeService.list(leWrapper);
System.out.println(leList);
}
回到頂部
3. between、notBetween
說明：
between：在值1和值2之間，notBetween：不在值1和值2之間
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> betweenWrapper = new QueryWrapper<>();
//between() 區間的值
betweenWrapper.between("age", 10, 20);
List<Employee> betweenList = employeeService.list(betweenWrapper);
System.out.println(betweenList );
//**********************
QueryWrapper<Employee> notBetweenWrapper = new QueryWrapper<>();
//notBetween() 不在區間的值
notBetweenWrapper.notBetween("age", 10, 21);
List<Employee> notBetweenList = employeeService.list(notBetweenWrapper );
System.out.println(notBetweenList );
}
回到頂部
4. like、notLike、likeLeft、likeRight
說明：
like：’%值%’，notLike：’%值%’，likeLeft：’%值’，likeRight：'值%'
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> likeWrapper = new QueryWrapper<>();
//like() 模糊查詢匹配值
likeWrapper.like("last_name", "s");
List<Employee> likeList = employeeService.list(likeWrapper);
System.out.println(likeList );
//**********************
QueryWrapper<Employee> notLikeWrapper = new QueryWrapper<>();
//notLike() 模糊查詢不匹配值
notLikeWrapper.notLike("last_name", "s");
List<Employee> notLikeList = employeeService.list(notLikeWrapper);
System.out.println(notLikeList);
}
@Test
public void contextLoads(){
QueryWrapper<Employee> likeLeftWrapper = new QueryWrapper<>();
//likeLeft() 模糊查詢匹配最後一位值
likeLeftWrapper.likeLeft("last_name", "s");
List<Employee> likeLeftList = employeeService.list(likeLeftWrapper);
System.out.println(likeLeftList );
//**********************
QueryWrapper<Employee> likeRightWrapper = new QueryWrapper<>();
//likeRight() 模糊查詢匹配第一位值
likeRightWrapper.likeRight("last_name", "s");
List<Employee> likeRightList = employeeService.list(likeRightWrapper );
System.out.println(likeRightList );
}
回到頂部
5. isNull、isNotNull
說明：
isNull：欄位 IS NULL，isNotNull：欄位 IS NOT NULL
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> isNullWrapper = new QueryWrapper<>();
//isNull() 為空
isNullWrapper.isNull("email");
List<Employee> isNullList = employeeService.list(isNullWrapper);
System.out.println(isNullList );
//**********************
QueryWrapper<Employee> isNotNullWrapper = new QueryWrapper<>();
//isNotNull() 不為空
isNotNullWrapper.isNotNull("last_name", "s");
List<Employee> isNotNullList = employeeService.list(isNotNullWrapper );
System.out.println(isNotNullList );
}
回到頂部
6. in、notIn
說明：
in：欄位 IN (v0, v1, …)，notIn：欄位 NOT IN (value.get(0), value.get(1), …)
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> inWrapper = new QueryWrapper<>();
//in() 符合多個條件的值
inWrapper.in("age", 8, 16, 26);
List<Employee> inList = employeeService.list(inWrapper);
System.out.println(inList );
//**********************
QueryWrapper<Employee> notInWrapper= new QueryWrapper<>();
//notIn() 不符合多個條件的值
notInWrapper.notIn("age", 8, 16, 26);
List<Employee> notInList = employeeService.list(notInWrapper);
System.out.println(notInList );
}
回到頂部
7. or、and
說明：
or：或者 ，and：和
注意事項:
主動呼叫or表示緊接著下一個方法不是用and連線!(不呼叫or則預設為使用and連線)
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> orWrapper = new QueryWrapper<>();
//or() 查詢age大於20 或者 gender等於1 的資料
orWrapper.gt("age", 20).or().eq("gender", 1);
List<Employee> orList = employeeService.list(orWrapper);
System.out.println(orList );
}
@Test
public void contextLoads(){
QueryWrapper<Employee> andWrapper = new QueryWrapper<>();
//and() 查詢last_name等於皮皮蝦b 和 gender等於1 的資料 (不使用and() 預設就是and())
andWrapper.eq("last_name", "皮皮蝦b").eq("gender", 1);
List<Employee> andList = employeeService.list(andWrapper );
System.out.println(andList);
}
回到頂部
8. orderByAsc、orderByDesc
說明：
orderByAsc：升序：ORDER BY 欄位, … ASC，orderByDesc：降序：ORDER BY 欄位, … DESC
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> Wrapper = new QueryWrapper<>();
//orderByAsc() 升序排序
Wrapper.orderByAsc("id");
List<Employee> list = employeeService.list(Wrapper);
for(Employee e : list) {
System.out.println(e);
}
}
@Test
public void contextLoads(){
QueryWrapper<Employee> Wrapper = new QueryWrapper<>();
//orderByDesc() 降序排序
Wrapper.orderByDesc("id");
List<Employee> list = employeeService.list(Wrapper);
for(Employee e : list) {
System.out.println(e);
}
}
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9. inSql、notInSql (不常用)
說明：
inSql：欄位 IN ( sql語句 )，notInSql：欄位 NOT IN ( sql語句 )
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> inSqlWrapper = new QueryWrapper<>();
//inSql() 符合sql語句的值
inSqlWrapper .inSql("select id from employee where id < 10");
List<Employee> inSqlList = employeeService.list(inSqlWrapper );
System.out.println(inSqlList );
//**********************
QueryWrapper<Employee> notInSqlWrapper= new QueryWrapper<>();
//notInSql() 不符合sql語句的值
notInSqlWrapper.notInSql("select id from employee where id < 10");
List<Employee> notInSqlList = employeeService.list(notInSqlWrapper);
System.out.println(notInSqlList );
}
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10. exists、notExists (不常用)
說明：
exists：拼接 EXISTS ( sql語句 )，notExists：拼接 NOT EXISTS ( sql語句 )
測試：
@Test
public void contextLoads(){
QueryWrapper<Employee> existsWrapper = new QueryWrapper<>();
//exists() 查詢符合sql語句的值
existsWrapper.exists("select last_name,gender from employee where id = 1");
List<Employee> existsList = employeeService.list(existsWrapper);
System.out.println(existsList );
//**********************
QueryWrapper<Employee> notExistsWrapper = new QueryWrapper<>();
//notExists() 查詢不符合sql語句的值
notExistsWrapper.notExists("select last_name,gender from employee where id = 1");
List<Employee> notExistsList = employeeService.list(notExistsWrapper);
System.out.println(notExistsList );
}