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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. 测试用表: 1. eq、ne说明: eq:等于,ne:不等于 测试: @Test public void contextLoads(){ QueryWrapper wrapper = new QueryWrapper(); //eq() 等于 wrapper.eq("last_name", "皮皮虾"); Employee one = employeeService.getOne(wrapper); System.out.println(one); } @Test public void contextLoads(){ QueryWrapper wrapper = new QueryWrapper(); //ne() 不等于 wrapper.ne("gender", 0); List list = employeeService.list(wrapper); System.out.println(list); } 2. gt、ge、lt、le说明: gt:大于,ge:大于等于,lt:小于,le:小于等于 测试: @Test public void contextLoads(){ QueryWrapper gtWrapper = new QueryWrapper(); //gt() 大于 gtWrapper.gt("age", 27); List gtList = employeeService.list(gtWrapper); System.out.println(gtList); //********************** QueryWrapper geWrapper = new QueryWrapper(); //ge() 大于等于 geWrapper.ge("age", 26); List geList = employeeService.list(geWrapper); System.out.println(geList); } @Test public void contextLoads(){ QueryWrapper ltWrapper = new QueryWrapper(); //lt() 小于 ltWrapper.lt("age", 12); List ltList = employeeService.list(ltWrapper); System.out.println(ltList); //********************** QueryWrapper geWrapper = new QueryWrapper(); //le() 小于等于 leWrapper.le("age", 12); List leList = employeeService.list(leWrapper); System.out.println(leList); } 3. between、notBetween说明: between:在值1和值2之间,notBetween:不在值1和值2之间 测试: @Test public void contextLoads(){ QueryWrapper betweenWrapper = new QueryWrapper(); //between() 区间的值 betweenWrapper.between("age", 10, 20); List betweenList = employeeService.list(betweenWrapper); System.out.println(betweenList ); //********************** QueryWrapper notBetweenWrapper = new QueryWrapper(); //notBetween() 不在区间的值 notBetweenWrapper.notBetween("age", 10, 21); List notBetweenList = employeeService.list(notBetweenWrapper ); System.out.println(notBetweenList ); } 4. like、notLike、likeLeft、likeRight说明: like:’%值%’,notLike:’%值%’,likeLeft:’%值’,likeRight:'值%' 测试: @Test public void contextLoads(){ QueryWrapper likeWrapper = new QueryWrapper(); //like() 模糊查询匹配值 likeWrapper.like("last_name", "s"); List likeList = employeeService.list(likeWrapper); System.out.println(likeList ); //********************** QueryWrapper notLikeWrapper = new QueryWrapper(); //notLike() 模糊查询不匹配值 notLikeWrapper.notLike("last_name", "s"); List notLikeList = employeeService.list(notLikeWrapper); System.out.println(notLikeList); } @Test public void contextLoads(){ QueryWrapper likeLeftWrapper = new QueryWrapper(); //likeLeft() 模糊查询匹配最后一位值 likeLeftWrapper.likeLeft("last_name", "s"); List likeLeftList = employeeService.list(likeLeftWrapper); System.out.println(likeLeftList ); //********************** QueryWrapper likeRightWrapper = new QueryWrapper(); //likeRight() 模糊查询匹配第一位值 likeRightWrapper.likeRight("last_name", "s"); List likeRightList = employeeService.list(likeRightWrapper ); System.out.println(likeRightList ); } 5. isNull、isNotNull说明: isNull:字段 IS NULL,isNotNull:字段 IS NOT NULL 测试: @Test public void contextLoads(){ QueryWrapper isNullWrapper = new QueryWrapper(); //isNull() 为空 isNullWrapper.isNull("email"); List isNullList = employeeService.list(isNullWrapper); System.out.println(isNullList ); //********************** QueryWrapper isNotNullWrapper = new QueryWrapper(); //isNotNull() 不为空 isNotNullWrapper.isNotNull("last_name", "s"); List isNotNullList = employeeService.list(isNotNullWrapper ); System.out.println(isNotNullList ); } 6. in、notIn说明: in:字段 IN (v0, v1, …),notIn:字段 NOT IN (value.get(0), value.get(1), …) 测试: @Test public void contextLoads(){ QueryWrapper inWrapper = new QueryWrapper(); //in() 符合多个条件的值 inWrapper.in("age", 8, 16, 26); List inList = employeeService.list(inWrapper); System.out.println(inList ); //********************** QueryWrapper notInWrapper= new QueryWrapper(); //notIn() 不符合多个条件的值 notInWrapper.notIn("age", 8, 16, 26); List notInList = employeeService.list(notInWrapper); System.out.println(notInList ); } 7. or、and说明: or:或者 ,and:和 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) 测试: @Test public void contextLoads(){ QueryWrapper orWrapper = new QueryWrapper(); //or() 查询age大于20 或者 gender等于1 的数据 orWrapper.gt("age", 20).or().eq("gender", 1); List orList = employeeService.list(orWrapper); System.out.println(orList ); } @Test public void contextLoads(){ QueryWrapper andWrapper = new QueryWrapper(); //and() 查询last_name等于皮皮虾b 和 gender等于1 的数据 (不使用and() 默认就是and()) andWrapper.eq("last_name", "皮皮虾b").eq("gender", 1); List andList = employeeService.list(andWrapper ); System.out.println(andList); } 8. orderByAsc、orderByDesc说明: orderByAsc:升序:ORDER BY 字段, … ASC,orderByDesc:降序:ORDER BY 字段, … DESC 测试: @Test public void contextLoads(){ QueryWrapper Wrapper = new QueryWrapper(); //orderByAsc() 升序排序 Wrapper.orderByAsc("id"); List list = employeeService.list(Wrapper); for(Employee e : list) { System.out.println(e); } } @Test public void contextLoads(){ QueryWrapper Wrapper = new QueryWrapper(); //orderByDesc() 降序排序 Wrapper.orderByDesc("id"); List list = employeeService.list(Wrapper); for(Employee e : list) { System.out.println(e); } } 9. inSql、notInSql (不常用)说明: inSql:字段 IN ( sql语句 ),notInSql:字段 NOT IN ( sql语句 ) 测试: @Test public void contextLoads(){ QueryWrapper inSqlWrapper = new QueryWrapper(); //inSql() 符合sql语句的值 inSqlWrapper .inSql("select id from employee where id < 10"); List inSqlList = employeeService.list(inSqlWrapper ); System.out.println(inSqlList ); //********************** QueryWrapper notInSqlWrapper= new QueryWrapper(); //notInSql() 不符合sql语句的值 notInSqlWrapper.notInSql("select id from employee where id < 10"); List notInSqlList = employeeService.list(notInSqlWrapper); System.out.println(notInSqlList ); } 10. exists、notExists (不常用)说明: exists:拼接 EXISTS ( sql语句 ),notExists:拼接 NOT EXISTS ( sql语句 ) 测试: @Test public void contextLoads(){ QueryWrapper existsWrapper = new QueryWrapper(); //exists() 查询符合sql语句的值 existsWrapper.exists("select last_name,gender from employee where id = 1"); List existsList = employeeService.list(existsWrapper); System.out.println(existsList ); //********************** QueryWrapper notExistsWrapper = new QueryWrapper(); //notExists() 查询不符合sql语句的值 notExistsWrapper.notExists("select last_name,gender from employee where id = 1"); List notExistsList = employeeService.list(notExistsWrapper); System.out.println(notExistsList ); }
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