Android SQLite(1)简单示例-增,删,改,查

1.主要核心类,Sqlite编程要继承SQLiteOpenHelper

 import android.content.Context;
 import android.database.sqlite.SQLiteDatabase;
 import android.database.sqlite.SQLiteDatabase.CursorFactory;
 import android.database.sqlite.SQLiteOpenHelper;

 public class MySQLiteOpenHelper extends SQLiteOpenHelper {
     //创建数据库
     public MySQLiteOpenHelper(Context context, String name,
             CursorFactory factory, int version) {
         //当系统发现version高于在本机上存在的版本时,会执行onUpgrade来更新
         super(context, name, factory, version);
     }
     @Override
     public void onCreate(SQLiteDatabase db) {
     }

     @Override
     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

     }
 }

2.增,查

 package com.example.sqlite;

 import com.example.sqlite.core.MySQLiteOpenHelper;
 import com.example.sqlite.listview.SqliteListActivity;

 import android.support.v7.app.ActionBarActivity;
 import android.content.ContentValues;
 import android.content.Intent;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
 import android.view.Menu;
 import android.view.MenuItem;
 import android.view.View;
 import android.widget.TextView;

 public class MainActivity extends ActionBarActivity {
     public static final String DB_NAME = "mydb";
     public static final String DB_COLUMN_NAME = "name";
     public static final String DB_COLUMN_GENDER = "gender";
     public static final String DB_TABLE = "user";
     MySQLiteOpenHelper dbhelper ;

     void create_table(){
         SQLiteDatabase dbWireter = dbhelper.getWritableDatabase();
         String sql = String.format("CREATE TABLE if not exists %s(%s %s DEFAULT %s,%s %s DEFAULT %s)",
                 DB_TABLE,
                 DB_COLUMN_NAME,"TEXT","NONE",
                 DB_COLUMN_GENDER,"TEXT","NONE");
         dbWireter.execSQL(sql);
         dbWireter.close();
     }
     void initsqlite(){
         dbhelper = new MySQLiteOpenHelper(this,DB_NAME,null,);
         create_table();
     }
     private void write_sqlite(){
         SQLiteDatabase dbWireter = dbhelper.getWritableDatabase();
         for (int i = ; i < ; i++) {
             ContentValues cv = new ContentValues();
             cv.put(DB_COLUMN_NAME, "zhang"+i);
             cv.put(DB_COLUMN_GENDER, "male");
             dbWireter.insert(DB_TABLE, null, cv);
         }
         TextView out = (TextView) findViewById(R.id.tvOut);
         out.setText("write succ");
         dbWireter.close();
     }
     private void select_sqlite(){
         SQLiteDatabase dbReader = dbhelper.getReadableDatabase();
         Cursor c = dbReader.query(DB_TABLE, null, null, null, null, null, null);
         String txt = "";
         while(c.moveToNext()){
             String name = c.getString(c.getColumnIndex(DB_COLUMN_NAME));
             String gender = c.getString(c.getColumnIndex(DB_COLUMN_GENDER));
             txt += "name="+name+" gender="+ gender +"\n";
         }
         TextView out = (TextView) findViewById(R.id.tvOut);
         out.setText(txt);
         dbReader.close();
     }
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         setContentView(R.layout.activity_main);

         initsqlite();

         findViewById(R.id.btn_show_inList).setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 startActivity(new Intent(MainActivity.this,SqliteListActivity.class));
             }
         });
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
         getMenuInflater().inflate(R.menu.main, menu);
         return true;
     }

     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         // Handle action bar item clicks here. The action bar will
         // automatically handle clicks on the Home/Up button, so long
         // as you specify a parent activity in AndroidManifest.xml.
         int id = item.getItemId();
         switch(id){
         case R.id.action_create:
             create_table();
             break;
         case R.id.action_write:
             write_sqlite();
             break;
         case R.id.action_read:
             select_sqlite();
             break;
         }
         return true;
     }
 } 

3.改,删

 import com.example.sqlite.R;
 import com.example.sqlite.core.MySQLiteOpenHelper;

 import android.support.v7.app.ActionBarActivity;
 import android.app.AlertDialog;
 import android.content.ContentValues;
 import android.content.DialogInterface;
 import android.database.Cursor;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.AdapterView.OnItemLongClickListener;
 import android.widget.EditText;
 import android.widget.ListView;
 import android.widget.SimpleCursorAdapter;

 public class SqliteListActivity extends ActionBarActivity {
     static final String DB = "dbinlist";
     static final String TABLE = "user";
     static final String NAME = "name";
     static final String GENDER = "gender";

     SimpleCursorAdapter adapter;
     ListView list;
     Cursor cur;
     MySQLiteOpenHelper dbhelper ;
     SQLiteDatabase writer,reader;

     OnItemLongClickListener itemLongListener = new OnItemLongClickListener() {

         @Override
         public boolean onItemLongClick(AdapterView<?> parent, View view,
                 final int position, long id) {
             new AlertDialog.Builder(SqliteListActivity.this).setMessage("what's your choice?")
             .setNegativeButton("update",new DialogInterface.OnClickListener() {
                 //更新
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                     Cursor c = adapter.getCursor();
                     c.moveToPosition(position);
                     int _id = c.getInt(c.getColumnIndex("_id"));
                     ContentValues cv = new ContentValues();
                     cv.put(NAME,"未名"+_id );
                     cv.put(GENDER,"未知"+_id );
                     writer.update(TABLE, cv,"_id=?",new String[]{_id+""});
                     refreshView();
                 }})
             .setPositiveButton("delete", new DialogInterface.OnClickListener() {
                 //删除
                 @Override
                 public void onClick(DialogInterface dialog, int which) {
                     Cursor c = adapter.getCursor();
                     c.moveToPosition(position);
                     int _id = c.getInt(c.getColumnIndex("_id"));
                     writer.delete(TABLE, "_id=?", new String[]{_id+""});//_id=?用问号是防止注入
                     refreshView();
                 }
             }).show();
             return true;
         }
     };

     View.OnClickListener btnListener = new View.OnClickListener() {
         @Override
         public void onClick(View v) {
             final EditText name = (EditText) findViewById(R.id.edtName);
             final EditText gender = (EditText) findViewById(R.id.edtGender);
             ContentValues cv = new ContentValues();
             cv.put(NAME, name.getText().toString());
             cv.put(GENDER, gender.getText().toString());
             writer.insert(TABLE, null, cv);
             refreshView();
         }
     };

     void refreshView(){
         cur = reader.query(TABLE, null, null, null, null, null, null);
         adapter.changeCursor(cur);
     }
     void createTable(){
         String sql = String.format(
                 "CREATE TABLE if not exists %s(_id INTEGER PRIMARY KEY autoincrement , %s %s DEFAULT %s,%s %s DEFAULT %s)", TABLE,
                 NAME, "TEXT", "NONE", GENDER, "TEXT", "NONE");
         writer.execSQL(sql);
     }
     void initDataBase(){
         dbhelper = new MySQLiteOpenHelper(this,DB,null,);
         writer = dbhelper.getWritableDatabase();
         reader = dbhelper.getReadableDatabase();
         createTable();
         refreshView();
     }
     void initList(){
         list = (ListView) findViewById(R.id.sqlite_list);
         list.setOnItemLongClickListener(itemLongListener);;
         adapter = new SimpleCursorAdapter(this,
                 R.layout.list_cell, cur,
                 new String[] { "_id","name","gender" }, new int[] {R.id.tv_id,R.id.tv_cell_name,R.id.tv_cell_gender });
         list.setAdapter(adapter);
         findViewById(R.id.btnAddUser).setOnClickListener(btnListener);
     }

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_list_sqlite);
         initList();
         initDataBase();
     }
 }