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)