android SQLite的CRUD

activity12.java

package com.wansha;import android.app.Activity;import android.content.ContentValues;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import com.wansha.db.DatabaseHelper;public class Activity12 extends Activity {private Button createDatabase;private Button updateDatabase;private Button insert;private Button update;private Button read;private Button delete;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);    this.createDatabase = (Button)this.findViewById(R.id.createDatabase);    this.createDatabase.setOnClickListener(new CreateDatabaseListener());        this.updateDatabase = (Button)this.findViewById(R.id.updateDatabase);    this.updateDatabase.setOnClickListener(new UpdateDatabaseListener());        this.insert = (Button)this.findViewById(R.id.insert);    this.insert.setOnClickListener(new InsertListener());        this.update = (Button)this.findViewById(R.id.update);    this.update.setOnClickListener(new UpdateListener());        this.read = (Button)this.findViewById(R.id.read);    this.read.setOnClickListener(new ReadListener());        this.delete = (Button)this.findViewById(R.id.delete);    this.delete.setOnClickListener(new DeleteListener());        }    class CreateDatabaseListener implements OnClickListener{    @Override    public void onClick(View v) {    SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");    sqlite.getReadableDatabase();    }    }    class UpdateDatabaseListener implements OnClickListener{    @Override    public void onClick(View v) {    System.out.println("UpdateDatabaseListener  is invoked !!!");    SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp",2);    sqlite.getReadableDatabase();    }    }    class InsertListener implements OnClickListener{    @Override    public void onClick(View v) {    SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");    SQLiteDatabase database = sqlite.getWritableDatabase();    ContentValues values = new ContentValues();    values.put("username", "xiaopeng");    database.insert("sharp", null, values);    }    }    class UpdateListener implements OnClickListener{    @Override    public void onClick(View v) {    SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");    SQLiteDatabase database = sqlite.getWritableDatabase();    ContentValues values = new ContentValues();    values.put("username", "pengpeng");    database.update("sharp", values, "id=?", new String[]{"2"});    }    }    class ReadListener implements OnClickListener{    @Override    public void onClick(View v) {    SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");    SQLiteDatabase database = sqlite.getWritableDatabase();    Cursor cursor = database.query("sharp", new String[]{"id","username"}, null, null, null, null, null);    while(cursor.moveToNext()){    String username = cursor.getString(cursor.getColumnIndex("username"));    System.out.println("username---->" + username);    }    }    }    class DeleteListener implements OnClickListener{    @Override    public void onClick(View v) {    SQLiteOpenHelper sqlite = new DatabaseHelper(Activity12.this,"sharp");    SQLiteDatabase database = sqlite.getWritableDatabase();    database.delete("sharp", "id=?", new String[]{"1"});    }    }}

main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" ><Button android:id="@+id/createDatabase"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="创建数据库"    /><Button android:id="@+id/updateDatabase"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="更新数据库"    /><Button android:id="@+id/insert"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="插入数据"    /><Button android:id="@+id/update"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="更新数据"    /><Button android:id="@+id/read"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="读取数据"    /><Button android:id="@+id/delete"    android:layout_width="fill_parent"    android:layout_height="wrap_content"    android:text="删除数据"    /></LinearLayout>

db.execSQL("create table sharp(id integer primary key autoincrement, username varchar(255))");

创建自增长ID

DatebaseHelper.java

package com.wansha.db;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;public class DatabaseHelper extends SQLiteOpenHelper{private static final int VERSION = 1;public DatabaseHelper(Context context, String name, CursorFactory factory,int version) {super(context, name, factory, version);}public DatabaseHelper(Context context, String name,int version) {this(context, name, null, version);}public DatabaseHelper(Context context, String name) {this(context, name, VERSION);}@Overridepublic void onCreate(SQLiteDatabase db) {System.out.println("create table is invoked !!!");db.execSQL("create table sharp(id integer primary key autoincrement, username varchar(255))");}@Overridepublic void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {System.out.println("update table is invoked !!!");}}

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