单例模式
static DbUtils db = null;
public static DbUtils getDb(Context context) {
if (context == null) {
context = DoctorApplication.getInstance();
}
if (db == null) {
db = DbUtils.create(context, "xUtils.db");
});
db.configAllowTransaction(true);
return db;
}
db.configAllowTransaction(true);
return db;
}
创建实体
@Table(name = "User")
public class User {
private int id; //主键ID，必须
private String uid;
private String type;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getUid() {
return uid;
}
public void setUid(String uid) {
this.uid = uid;
}
}
// 查找,根据主键ID查找
User userTemp = db.findById(User.class, user.getId());
List<User> list = db.findAll(User.class);//通过类型查找，查找所有
User user = db.findFirst(Selector.from(User.class).where("type","=","0"));
// IS NULL
User user = db.findFirst(Selector.from(User.class).where("type","=", null));
// IS NOT NULL
User user = db.findFirst(Selector.from(User.class).where("type","!=", null));
List<User> list = db.findAll(Selector.from(User)
.where("id" ,"<", 54)
.and(WhereBuilder.b("id", ">", 20).or("id", " < ", 30))
.orderBy("id")
.limit(pageSize)
.offset(pageSize * pageIndex));
// 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)
User test = db.findFirst(Selector.from(User.class).where("id", "in", new int[]{1, 2, 3}));
// 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)
User test = db.findFirst(Selector.from(User.class).where("uid", "between", new String[]{"1", "5"}));
DbModel dbModel = db.findDbModelAll(Selector.from(User.class).select("uid"));//select("name")只取出name列
List<DbModel> dbModels = db.findDbModelAll(Selector.from(User.class).groupBy("type").select("uid", "count(uid)"));
...
List<DbModel> dbModels = db.findDbModelAll(sql); // 自定义sql查询
db.execNonQuery(sql) // 执行自定义sql
//多条件混合查询
List<User> userEnts = TCommUtil.getDb(this).findAll(Selector.from(User.class).where(WhereBuilder.b("id", ">", 5).or("id", "<", 3)).and("uid", "=", "0"));
//模糊查询like
String str = "select id,nickname,age,gender,zhenduan,avatar,pid,type from User where uid = "
+ uid
+ " and type like '%"
+ value + "%'";
Cursor cursor = TCommUtil.getDb(this).execQuery(str);
cursor.moveToFirst();
for (int i = 0; i < cursor.getCount(); i++) {
User userEnt = new User();
userEnt.setId(cursor.getInt(0));
...
cursor.moveToNext();
}
cursor.close();
基础操作