QueryWrapper条件构造器 验证

allEq

官方文档：

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

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

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'

验证boolean null2IsNull：

@Test
    public void allEq() {
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        Map<String,String> params = new HashMap<>();
        params.put("name",null);
        **queryWrapper.allEq(params);**
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }

boolean null2IsNull = true 结果：
TCourse(id=13, name=null)
boolean null2IsNull = false`在这里插入代码片` 结果：
TCourse(id=2, name=math)
TCourse(id=3, name=英语)
TCourse(id=4, name=物理)
TCourse(id=5, name=政治)
TCourse(id=6, name=化学)
TCourse(id=7, name=生物)
TCourse(id=8, name=history)
TCourse(id=9, name=劳动)
TCourse(id=10, name=体育)
TCourse(id=11, name=music)
TCourse(id=12, name=美术)
TCourse(id=13, name=null)

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

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'

验证BiPredicate<R, V> filter

@Test
    public void allEqBiPredicate() {
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        Map<String,String> params = new HashMap<>();
        params.put("name","英语");
        params.put("id","4");
        queryWrapper.allEq((k,v)->k.equals("id"),params);
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }
结果：
TCourse(id=4, name=物理)

filter:过滤条件：key为“id”的条件被加入到筛选条件中
相当于：

allEq((k,v)->k.equals("id"),params)---->id = "4"
allEq(params)---->id = "4" and name = "英语"

eq,ne,gt,ge,lt,le

值得一提的是，除了可以比较数字大小外，还可以比较字母

@Test
    public void le(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.le("name","w");
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }
    结果：
    TCourse(id=2, name=math)
	TCourse(id=8, name=history)
	TCourse(id=11, name=music)

between 和 notBetween

@Test
    public void between(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.between("name","a","z");
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }

TCourse(id=2, name=math)
TCourse(id=8, name=history)
TCourse(id=11, name=music)

@Test
    public void notBetween(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.notBetween("name","a","z");
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }

TCourse(id=3, name=英语)
TCourse(id=4, name=物理)
TCourse(id=5, name=政治)
TCourse(id=6, name=化学)
TCourse(id=7, name=生物)
TCourse(id=9, name=劳动)
TCourse(id=10, name=体育)
TCourse(id=12, name=美术)

like,notLike,likeLeft,likeRight

likeLeft:%值

@Test
    public void likeLeft(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.likeLeft("name","物");
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }

TCourse(id=7, name=生物)

likeRight:值%

@Test
    public void likeRight(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.likeRight("name","物");
        List<TCourse> list = itCourseService.list(queryWrapper);
        for(TCourse tCourse:list){
    
    
            System.out.println(tCourse);
        }
    }

TCourse(id=4, name=物理)

isNull,isNotNull,in,notIn

@Test
    public void isNull(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.isNull("name");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

inSql

@Test
    public void inSql(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.inSql("id","1,2,3,4");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

结果：
TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=3, name=英语, type=文科, haveExam=true)
TCourse(id=4, name=物理, type=理科, haveExam=true)

@Test
    public void inSql(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.inSql("id","select id from t_course where id > 5 ");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

结果
TCourse(id=6, name=化学, type=理科, haveExam=false)
TCourse(id=7, name=生物, type=理科, haveExam=false)
TCourse(id=8, name=history, type=文科, haveExam=false)
TCourse(id=9, name=劳动, type=艺术, haveExam=true)
TCourse(id=10, name=体育, type=艺术, haveExam=true)
TCourse(id=11, name=music, type=艺术, haveExam=false)
TCourse(id=12, name=美术, type=艺术, haveExam=false)
TCourse(id=13, name=null, type=null, haveExam=false)

groupBy

可以传多个列

@Test
    public void groupBy(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.groupBy("type","have_exam");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

结果：
TCourse(id=13, name=null, type=null, haveExam=false)
TCourse(id=8, name=history, type=文科, haveExam=false)
TCourse(id=3, name=英语, type=文科, haveExam=true)
TCourse(id=6, name=化学, type=理科, haveExam=false)
TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=11, name=music, type=艺术, haveExam=false)
TCourse(id=9, name=劳动, type=艺术, haveExam=true)

orderByAsc，orderByDesc，orderBy

@Test
    public void orderBy(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByAsc("type");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=13, name=null, type=null, haveExam=false)
TCourse(id=3, name=英语, type=文科, haveExam=true)
TCourse(id=5, name=政治, type=文科, haveExam=true)
TCourse(id=8, name=history, type=文科, haveExam=false)
TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=4, name=物理, type=理科, haveExam=true)
TCourse(id=6, name=化学, type=理科, haveExam=false)
TCourse(id=7, name=生物, type=理科, haveExam=false)
TCourse(id=9, name=劳动, type=艺术, haveExam=true)
TCourse(id=10, name=体育, type=艺术, haveExam=true)
TCourse(id=11, name=music, type=艺术, haveExam=false)
TCourse(id=12, name=美术, type=艺术, haveExam=false)

//也可以传多个参数
@Test
    public void orderBy(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderByAsc("type","name");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=13, name=null, type=null, haveExam=false)
TCourse(id=8, name=history, type=文科, haveExam=false)
TCourse(id=5, name=政治, type=文科, haveExam=true)
TCourse(id=3, name=英语, type=文科, haveExam=true)
TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=6, name=化学, type=理科, haveExam=false)
TCourse(id=4, name=物理, type=理科, haveExam=true)
TCourse(id=7, name=生物, type=理科, haveExam=false)
TCourse(id=11, name=music, type=艺术, haveExam=false)
TCourse(id=10, name=体育, type=艺术, haveExam=true)
TCourse(id=9, name=劳动, type=艺术, haveExam=true)
TCourse(id=12, name=美术, type=艺术, haveExam=false)

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

@Test
    public void orderBy(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.orderBy(true,false,"type","name");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=12, name=美术, type=艺术, haveExam=false)
TCourse(id=9, name=劳动, type=艺术, haveExam=true)
TCourse(id=10, name=体育, type=艺术, haveExam=true)
TCourse(id=11, name=music, type=艺术, haveExam=false)
TCourse(id=7, name=生物, type=理科, haveExam=false)
TCourse(id=4, name=物理, type=理科, haveExam=true)
TCourse(id=6, name=化学, type=理科, haveExam=false)
TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=3, name=英语, type=文科, haveExam=true)
TCourse(id=5, name=政治, type=文科, haveExam=true)
TCourse(id=8, name=history, type=文科, haveExam=false)
TCourse(id=13, name=null, type=null, haveExam=false)

having

@Test
    public void having(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.groupBy("type","have_exam")
                .having("count(*) >= 2");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=3, name=英语, type=文科, haveExam=true)
TCourse(id=6, name=化学, type=理科, haveExam=false)
TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=11, name=music, type=艺术, haveExam=false)
TCourse(id=9, name=劳动, type=艺术, haveExam=true)

func

func(Consumer<Children> consumer)
func(boolean condition, Consumer<Children> consumer)

func 方法(主要方便在出现if…else下调用不同方法能不断链)

@Test
    public void func(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.func(i -> {
    
    
            System.out.println(i);
            if(true) {
    
    
                i.eq("id", 3);
            } else {
    
    
                i.ne("id", 3);
            }
        });
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

or

or()
or(boolean condition)

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)

例: eq("id",1).or().eq("name","老王")--->id = 1 or name = '老王'

@Test
    public void or(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("id","2").or().eq("name","化学");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=math, type=理科, haveExam=true)
TCourse(id=6, name=化学, type=理科, haveExam=false)

or(Consumer<Param> consumer)
or(boolean condition, Consumer<Param> consumer)

OR 嵌套

例: or(i -> i.eq(“name”, “李白”).ne(“status”, “活着”))—>or (name = ‘李白’ and status <> ‘活着’)

@Test
    public void or2(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.or((i) -> i.eq("id","2").ne("name","化学"));
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=math, type=理科, haveExam=true)
--> or(id = '2' and name <> '化学')

and

and(Consumer<Param> consumer)
and(boolean condition, Consumer<Param> consumer)

AND 嵌套
例: and(i -> i.eq(“name”, “李白”).ne(“status”, “活着”))—>and (name = ‘李白’ and status <> ‘活着’)

@Test
    public void and(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.and((i) -> i.eq("id","2").ne("name","化学"));
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=math, type=理科, haveExam=true)

nested

nested(Consumer<Param> consumer)
nested(boolean condition, Consumer<Param> consumer)

正常嵌套 不带 AND 或者 OR
例: nested(i -> i.eq(“name”, “李白”).ne(“status”, “活着”))—>(name = ‘李白’ and status <> ‘活着’)

@Test
    public void nested(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.nested((i) -> i.eq("id","2").ne("name","化学"));
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=math, type=理科, haveExam=true)

apply

作用：拼接sql

@Test
    public void apply(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<TCourse>();
        queryWrapper.apply("date_format(date_column,'%Y-%m-%d') = {0}", "2008-08-08");
        //queryWrapper.eq("date_format(date_column,'%Y-%m-%d')", "2008-08-08");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=math, type=理科, haveExam=true)

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’")
以上第一种方式会有sql注入风险，不推荐使用。建议使用第二种方式。

last

last(String lastSql)
last(boolean condition, String lastSql)

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

例: last(“limit 1”)

@Test
    public void last(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.in("name", Arrays.asList("英语","物理","化学","政治","生物"))
                .last("limit 2");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=3, name=英语, type=文科, haveExam=true, dateColumn=Wed Sep 09 08:00:00 CST 2009)
TCourse(id=4, name=物理, type=理科, haveExam=true, dateColumn=null)

exists

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

拼接 EXISTS ( sql语句 )
例: exists(“select id from table where age = 1”)—>exists (select id from table where age = 1)

@Test
    public void exit(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.exists("select * from t_course where id > 5");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=math, type=理科, haveExam=true, dateColumn=Fri Aug 08 08:00:00 CST 2008)
TCourse(id=3, name=英语, type=文科, haveExam=true, dateColumn=Wed Sep 09 08:00:00 CST 2009)
TCourse(id=4, name=物理, type=理科, haveExam=true, dateColumn=null)
TCourse(id=5, name=政治, type=文科, haveExam=true, dateColumn=null)
TCourse(id=6, name=化学, type=理科, haveExam=false, dateColumn=null)
TCourse(id=7, name=生物, type=理科, haveExam=false, dateColumn=null)
TCourse(id=8, name=history, type=文科, haveExam=false, dateColumn=null)
TCourse(id=9, name=劳动, type=艺术, haveExam=true, dateColumn=null)
TCourse(id=10, name=体育, type=艺术, haveExam=true, dateColumn=null)
TCourse(id=11, name=music, type=艺术, haveExam=false, dateColumn=null)
TCourse(id=12, name=美术, type=艺术, haveExam=false, dateColumn=null)
TCourse(id=13, name=null, type=null, haveExam=false, dateColumn=null)

notExists

notExists(String notExistsSql)
notExists(boolean condition, String notExistsSql)

拼接 NOT EXISTS ( sql语句 )
例: notExists(“select id from table where age = 1”)—>not exists (select id from table where age = 1)

QueryWrapper

select

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

设置查询字段
说明:

以上方法分为两类.
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

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

@Test
    public void select(){
    
    
        QueryWrapper<TCourse> queryWrapper = new QueryWrapper<>();
        queryWrapper.select("id","type");
        List<TCourse> list = itCourseService.list(queryWrapper);
        list.forEach(System.out::println);
    }

TCourse(id=2, name=null, type=理科, haveExam=false, dateColumn=null)
TCourse(id=3, name=null, type=文科, haveExam=false, dateColumn=null)
TCourse(id=4, name=null, type=理科, haveExam=false, dateColumn=null)
TCourse(id=5, name=null, type=文科, haveExam=false, dateColumn=null)
TCourse(id=6, name=null, type=理科, haveExam=false, dateColumn=null)
TCourse(id=7, name=null, type=理科, haveExam=false, dateColumn=null)
TCourse(id=8, name=null, type=文科, haveExam=false, dateColumn=null)
TCourse(id=9, name=null, type=艺术, haveExam=false, dateColumn=null)
TCourse(id=10, name=null, type=艺术, haveExam=false, dateColumn=null)
TCourse(id=11, name=null, type=艺术, haveExam=false, dateColumn=null)
TCourse(id=12, name=null, type=艺术, haveExam=false, dateColumn=null)
TCourse(id=13, name=null, type=null, haveExam=false, dateColumn=null)