Xutils 按条件查找

//查

1. Parententity = db.findById(Parent.class, parent.getId());
   
2. Parententity = db.findFirst(entity);//通过entity的属性查找
   
3. List<Parent>list = db.findAll(entity);//通过entity的属性查找
   
4. List<Parent>list = db.findAll(Parent.class);//通过类型查找
   
5. ParentParent =db.findFirst(Selector.from(Parent.class).where("name","=","test"));
   
6. //IS NULL
   
7. ParentParent = db.findFirst(Selector.from(Parent.class).where("name","=",null));
   
8. //IS NOT NULL
   
9. ParentParent = db.findFirst(Selector.from(Parent.class).where("name","!=",null));
   
10. //WHERE id<54 AND (age>20 OR age<30) ORDER BY id LIMITpageSize OFFSET pageOffset
    
11. List<Parent>list = db.findAll(Selector.from(Parent.class)
    
12.                                   .where("id","<", 54)
    
13.                                   .and(WhereBuilder.b("age",">", 20).or("age", " < ", 30))
    
14.                                   .orderBy("id")
    
15.                                   .limit(pageSize)
    
16.                                   .offset(pageSize* pageIndex));
    
17. //op为"in"时，最后一个参数必须是数组或Iterable的实现类(例如List等)
    
18. Parenttest = db.findFirst(Selector.from(Parent.class).where("id","in", new int[]{1, 2, 3}));
    
19. //op为"between"时，最后一个参数必须是数组或Iterable的实现类(例如List等)
    
20. Parenttest = db.findFirst(Selector.from(Parent.class).where("id","between", new String[]{"1", "5"}));
    
21. DbModeldbModel =db.findDbModelAll(Selector.from(Parent.class).select("name"));//select("name")只取出name列
    
22. List<DbModel>dbModels =db.findDbModelAll(Selector.from(Parent.class).groupBy("name").select("name","count(name)"));
    
23. ...
    
24. List<DbModel>dbModels = db.findDbModelAll(sql); // 自定义sql查询
    
25. db.execNonQuery(sql)// 执行自定义sql