Android xutils Frame (i) dbutils

Frame Address: Https://github.com/wyouflf/xUtils

The permissions Required

< uses-permission android:name="Android.permission.INTERNET"/>

<uses-permissionandroid:name=" Android.permission.WRITE_EXTERNAL_STORAGE "/>

Create a database

Daoconfig config = new daoconfig (context);

Config.setdbname ("Xutils-demo"); DB name

Config.setdbversion (1); DB version

Dbutils db = dbutils.create (config),//db there are other construction methods, such as the listener that contains the version of the Update table.

Create a table

Db.createtableifnotexist (User. Class); Create a table user

Db.save (user);//Save a User object in the table. The user table is also created when the Save action is initially executed

Delete a table

Db.droptable (User.class);

Open transaction

Db.configallowtransaction (true);

DB related Annotati On

  @Check     Check constraint
  @ column   column name
  @ Finder   One-to-many, many-to-many relationships (see use in parent, child of sample)
  @ Foreign   FOREIGN key
  @ Id       PRIMARY key, when int type, default self-increment. Non-self-increment, you need to set the value of the ID
  @ noautoincrement   not self-increment
  @ notnull   not empty
  @ table     name
  @ Transient   Do not write database table structure
  @ unique   UNIQUE constraint

Some common methods

Dbutils db = Dbutils.create (this); User user = new user (); It is important to note that the user object must have an id attribute, or a property User.setemail ("[email protected]") with the @id annotation, user.setname ("Wyouflf");d B.save ( user); When you save an entity with Savebindingid, you assign a value to the ID of the entity ...//find the Parent entity = Db.findbyid (Parent.class, Parent.getid ()); list<parent> list = Db.findall (Parent.class);//Find parent parent = Db.findfirst by Type (Selector.from (Parent.class). Where ("name", "=", "Test")),//is nullparent Parent = Db.findfirst (Selector.from (Parent.class). WHERE ("name", "=", null) );//is not nullparent Parent = Db.findfirst (Selector.from (Parent.class). WHERE ("name", "! =", null));//Where id<54 and (age>20 OR age<30)                                   ORDER by ID LIMIT pageSize OFFSET pageoffsetlist<parent> list = Db.findall (Selector.from (Parent.class) . WHERE ("id", "<", si). and (Wherebuilder.b ("Age", ">",). or ( "Age", "<", ()). ("id").Limit (pageSize). Offset (pageSize * pageIndex));//OP is "in", the last parameter must be an array or an implementation class of iterable (for example, Li St, etc.) Parent test = Db.findfirst (Selector.from (Parent.class). WHERE ("id", "in", New Int[]{1, 2, 3});//OP is "between", The last parameter must be an array or Iterable implementation class (such as list, etc.), Parent test = Db.findfirst (Selector.from (Parent.class). WHERE ("id", "between", new string[]{"1", "5"}));D Bmodel Dbmodel = Db.finddbmodelall (Selector.from (Parent.class). Select ("name"));//select (" Name ") only remove the name column list<dbmodel> dbmodels = Db.finddbmodelall (Selector.from (Parent.class). GroupBy (" name "). Select ("Name", "Count (name)"); ... list<dbmodel> dbmodels = db.finddbmodelall (sql); Custom SQL query Db.execnonquery (SQL)//execute custom SQL ...

Android xutils Frame (i) dbutils