Android Development Learning-SQLite database and unit test, androidsqlite

Android Development Learning-SQLite database and unit test, androidsqlite

SQLite Database
Lightweight relational databases
The api required to create a database: SQLiteOpenHelper

 

Public class Myopenhelper extends SQLiteOpenHelper {// public Myopenhelper (Context context, String name, CursorFactory factory, int version) {// name database file name, cursor factory, database version super (context, name, factory, version);} // called at database creation @ Override public void onCreate (SQLiteDatabase db ){
// Create a table when creating a database. You can add, delete, modify, and query the table here. You only need to change the SQL statement in it !!! Db.exe cSQL ("create table person (_ id integer primary key autoincrement, name char (10), phone char (20), money integer (20 ))");} // this method is called during Database Upgrade @ Override public void onUpgrade (SQLiteDatabase arg0, int arg1, int arg2 ){}}

Create a database

Public class Testcase extends AndroidTestCase {public void test () {// getContext (): Obtain the virtual context. This is a test framework that facilitates the test of Myopenhelper oh = new Myopenhelper (getContext (), "people. db ", null, 1); // if the database does not exist, create a database first, and then obtain the readable and writable database objects. If yes, open SQLiteDatabase db = oh. getWritableDatabase (); // It is also a readable and writable database object. The database must be opened in read-only mode unless the storage space is full. // SQLiteDatabase db1 = oh. getReadableDatabase ();}}

The result is as follows:

Add, delete, modify, and query Databases
SQL statement
* Insert into person (name, phone, money) values ('zhang san', '123', 159874611 );
* Delete from person where name = 'Li si' and _ id = 4;
* Update person set money = 6000 where name = 'Li si ';
* Select name, phone from person where name = 'zhang san ';

Execute SQL statements to add, delete, modify, and query

// Insert
Db.exe cSQL ("insert into person (name, phone, money) values (?, ?, ?); ", New Object [] {" James ", 15987461,750 00 });
// Search
Cursor cs = db. rawQuery ("select _ id, name, money from person where name = ?; ", New String [] {" James "});
This method is called before the test method is executed.

Protected void setUp () throws Exception {
Super. setUp ();
// Obtain the virtual context object
Oh = new MyOpenHelper (getContext (), "people. db", null, 1 );
}
Use APIs for addition, deletion, modification, and query
* Insert
// Save the data to be stored in the database as a key-Value Pair
ContentValues cv = new ContentValues ();
Cv. put ("name", "Liu Neng ");
Cv. put ("phone", 1651646 );
Cv. put ("money", 3500 );
// The returned value is the primary key of the modified row. If an error occurs,-1 is returned.
Long I = db. insert ("person", null, cv );
* Delete

// The returned value is the number of deleted rows.
Int I = db. delete ("person", "_ id =? And name =? ", New String [] {" 1 "," James "});
* Modify

ContentValues cv = new ContentValues ();
Cv. put ("money", 25000 );
Int I = db. update ("person", cv, "name =? ", New String [] {" Zhao Si "});
* Query
// Arg1: The field to be queried
// Arg2: Query Condition
// Arg3: a placeholder for filling in query Conditions
Cursor cs = db. query ("person", new String [] {"name", "money"}, "name =? ", New String [] {" zhangsan "}, null );
While (cs. moveToNext ()){
// Obtain the index value of the specified Column
String name = cs. getString (cs. getColumnIndex ("name "));
String money = cs. getString (cs. getColumnIndex ("money "));
System. out. println (name + ";" + money );
}

 

Unit Test junit
Define a class that inherits AndroidTestCase. Define a method in the class to test this method.

 

Add:
When specifying the command set, targetPackage specifies the package name of the application you want to test.
<Instrumentation
Android: name = "android. test. InstrumentationTestRunner"
Android: targetPackage = "com. itheima. junit" // press alt +/to select it!
> </Instrumentation>
Define the class library used
<Uses-library android: name = "android. test. runner"> </uses-library>

The role of assertion to check whether the running result is consistent with the expectation
If an application exception occurs, it is thrown to the test framework.