Android--sqlite (Add, delete, change, check) operation Instance Code _android

5 classes are required:

1. Entity class: Person.java

2. Abstract class: Sqloperate.java (encapsulates the operation of the database)

3. Assistant class: Dbopenhelper.java (Inheriting Sqliteopenhelper)

4. Implementation class: Sqloperateimpl.java (Implement abstract class Sqloperate.java)

5. Test class: Test.java (Inherit androidtestcase)

1.person.java

Copy Code code as follows:

Package com.mrzhu.sqltite;

public class Person {

private int _id;
private String name;

public int getId () {
return _id;
}

public void setId (int _id) {
this._id = _id;
}

Public String GetName () {
return name;
}

public void SetName (String name) {
THIS.name = name;
}

@Override
Public String toString () {
return "person [id=" + _id + ", name=" + name + "]";
}

Public person () {
Super ();
}

public person (int _id, String name) {
Super ();
this._id = _id;
THIS.name = name;
}
}

2.sqloperate.java

Copy Code code as follows:

Package com.mrzhu.sqltite;

Import java.util.List;

/**
* Check and delete
* @author ZLQ
*
*/
Public interface Sqloperate {
public void Add (person P);
public void Delete (int id);
public void Updata (person P);
Public list<person> find ();
Public person FindByID (int id);
}

3.dbopenhelper.java

Copy Code code as follows:

Package com.mrzhu.sqltite;

Import Android.content.Context;
Import Android.database.sqlite.SQLiteDatabase;
Import Android.database.sqlite.SQLiteOpenHelper;

/**
* Assistant Class
* @author ZLQ
*
*/
public class Dbopnehelper extends Sqliteopenhelper {

private static final int version = 1;//version
private static final String db_name = "people.db";//Database name
public static final String student_table = "STUDENT";//Table name
public static final String _id = "_id";//Column name in table
public static final String name = "name";//Column name in table
Create a database statement, student_table,_id, add spaces around name
private static final String create_table = "CREATE TABLE" + student_table + ("+ _id +" Integer primary key Autoincre ment, "+ NAME +" text);

Public Dbopnehelper {
Super (context, db_name, NULL, VERSION);
}

Called when the database was first created
@Override
public void OnCreate (Sqlitedatabase db) {
Db.execsql (create_table);
}

Called when version is upgraded
@Override
public void Onupgrade (sqlitedatabase db, int oldversion, int newversion) {

}

}

4.sqloperateimpl.java

Copy Code code as follows:

Package com.mrzhu.sqltite;

Import java.util.ArrayList;
Import java.util.List;

Import android.content.ContentValues;
Import Android.content.Context;
Import Android.database.Cursor;
Import Android.database.sqlite.SQLiteDatabase;

public class Sqloperateimpl implements sqloperate{

Private Dbopnehelper Dbopenhelper;

Public Sqloperateimpl {
Dbopenhelper = new Dbopnehelper (context);
}

/**
* increase, insert data into the database with insert
*/
public void Add (person p) {
Sqlitedatabase db = Dbopenhelper.getwritabledatabase ();
Contentvalues values = new Contentvalues ();
Values.put (dbopnehelper._id, P.getid ());
Values.put (Dbopnehelper.name, P.getname ());
Db.insert (dbopnehelper.student_table, null, values);
}

/**
* Delete the data by ID
*/
public void Delete (int id) {
Sqlitedatabase db = Dbopenhelper.getwritabledatabase ();
Db.delete (dbopnehelper.student_table, dbopnehelper._id + "=?", new String[]{string.valueof (ID)});
}

 /**
  * Change the data for the specified ID
  */
 public void Updata (person p) {
   Sqlitedatabase db = Dbopenhelper.getwritabledatabase ();
  contentvalues values = new Contentvalues ();
  values.put (dbopnehelper._id, P.getid ());
  values.put (Dbopnehelper.name, P.getname ());
  db.update (dbopnehelper.student_table, values, dbopnehelper._id + "=?", New String[]{string.valueof ( P.getid ())});
 }

 /**
  * Check, all data in the query table
  */
 public list<person> Find () {
  list <Person> persons = NULL;
  sqlitedatabase db = Dbopenhelper.getreadabledatabase ();
  cursor Cursor = db.query (dbopnehelper.student_table, NULL, NULL, NULL, NULL, NULL, NULL);
  if (cursor!= null) {
   persons = new arraylist<person> ();
   while (Cursor.movetonext ()) {
    person person = new Person ();
    int _id = Cursor.getint (Cursor.getcolumnindex (dbopnehelper._id));
    string name = cursor.getstring (Cursor.getcolumnindex (dbopnehelper.name));
    person.setid (_id);
    person.setname (name);
    persons.add (person);
   }
  }
  return persons;
 }

/**
* Query the data for the specified ID
*/
Public person FindByID (int id) {
Sqlitedatabase db = Dbopenhelper.getreadabledatabase ();
Cursor Cursor = db.query (dbopnehelper.student_table, NULL, dbopnehelper._id + "=?", new String[]{string.valueof (ID)}, NULL, NULL, NULL);
person person = null;
if (cursor!= null && cursor.movetofirst ()) {
person = new person ();
int _id = Cursor.getint (Cursor.getcolumnindex (dbopnehelper._id));
String name = cursor.getstring (Cursor.getcolumnindex (dbopnehelper.name));
Person.setid (_id);
Person.setname (name);
}
return person;
}
}

5.test.java

Add to <application></application> outside of Androidmanifest.xml

(Targetpackage is the package name of the current project)

<instrumentation

Android:targetpackage= "Com.mrzhu.sqltite"

Android:name= "Android.test.InstrumentationTestRunner" >

</instrumentation>

Add <uses-library android:name= "Android.test.runner" to the <application></application>/>

Copy Code code as follows:

Package com.mrzhu.sqltite;

Import java.util.List;

Import Android.test.AndroidTestCase;
Import Android.util.Log;

public class Test extends Androidtestcase {
public void Testadd () throws exception{
Sqloperateimpl test = new Sqloperateimpl (GetContext ());
person person = new person (2, "Peter");
Test.add (person);
}

public void Testdelete () throws exception{
Sqloperateimpl test = new Sqloperateimpl (GetContext ());
Test.delete (1);
}

public void Testupdata () throws exception{
Sqloperateimpl test = new Sqloperateimpl (GetContext ());
person person = new person (1, "Tom");
Test.updata (person);
}

public void Testfind () throws exception{
Sqloperateimpl test = new Sqloperateimpl (GetContext ());
list<person> persons = Test.find ();
for (person Person:persons) {
LOG.I ("System.out", person.tostring ());
}
}

public void Testfindbyid () throws exception{
Sqloperateimpl test = new Sqloperateimpl (GetContext ());
Person person = Test.findbyid (2);
LOG.I ("System.out", person.tostring ());
}
}