android SQLite使用
package zhou.demo.sql;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteDatabase.CursorFactory;import android.database.sqlite.SQLiteOpenHelper;/** * 提供的功能 * 1：getReadableDatabase()，gerWritableDatabase()可以获取SQLiteDatabase对象，通过该对象进行相关操作 * 2：提供onCreate()和onUpgrade两个回调函数，允许我们在创建和升级数据库时，进行 * @author Administrator * */public class DatabaseHelper extends SQLiteOpenHelper{ private static final int VERSION = 1; /*** 该函数为继承SQLiteOpenHelper必须有的一个函数* @param context* @param name* @param factory* @param version*/ public DatabaseHelper(Context context, String name, CursorFactory factory, int version) {super(context, name, factory, version); } public DatabaseHelper(Context context, String name){this(context,name,VERSION); } public DatabaseHelper(Context context, String name, int version){this(context,name,null,version); } public void onCreate(SQLiteDatabase db) {System.out.println("数据库已经创建");db.execSQL("create table user(id int,name varchar(20))"); } public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {System.out.println("数据库已经更新"); }}操作数据库必须继承SQLiteOpenHelper不然会很麻烦，
package zhou.demo;import zhou.demo.sql.DatabaseHelper;import android.app.Activity;import android.content.ContentValues;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class SQLiteDemo extends Activity { private Button createButton; @SuppressWarnings("unused") private Button updateButton; private Button insertButton; private Button updateRecordButton; private Button queryButton; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); //进行控件的关联 createButton = (Button)this.findViewById(R.id.button1); updateButton = (Button)this.findViewById(R.id.button4); insertButton = (Button)this.findViewById(R.id.button3); updateRecordButton = (Button)this.findViewById(R.id.button2); queryButton = (Button)this.findViewById(R.id.button5); //进行操作的关联 createButton.setOnClickListener(new OnClickListener(){ @SuppressWarnings("unused") public void onClick(View v) { //创建数据库对象 DatabaseHelper dbHelper = new DatabaseHelper(SQLiteDemo.this,"zhou_table"); //调用才会真正的创建数据库 SQLiteDatabase db = dbHelper.getWritableDatabase(); } }); //更新数据库的版本 updateRecordButton.setOnClickListener(new OnClickListener(){ @SuppressWarnings("unused") @Override public void onClick(View v) { DatabaseHelper dbHelper = new DatabaseHelper(SQLiteDemo.this,"zhou_table",2); SQLiteDatabase db = dbHelper.getReadableDatabase(); } }); //插入监听 insertButton.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v) { // TODO Auto-generated method stub ContentValues values = new ContentValues(); values.put("id", 123); values.put("name", "zhouzhou"); DatabaseHelper dbHelper = new DatabaseHelper(SQLiteDemo.this,"zhou_table"); SQLiteDatabase db = dbHelper.getWritableDatabase(); db.insert("zhou_table", null, values); } }); //更新数据超早 updateRecordButton.setOnClickListener(new OnClickListener(){ public void onClick(View v) { DatabaseHelper dbHelper = new DatabaseHelper(SQLiteDemo.this,"zhou_table"); SQLiteDatabase db = dbHelper.getReadableDatabase(); ContentValues values = new ContentValues(); values.put("name", "周利军"); //把String数组的一个参数传给id（值值相互对应） db.update("zhou_table", values, "id=?", new String[]{"1"}); } }); //查询 queryButton.setOnClickListener(new OnClickListener(){ @Override public void onClick(View v) { // TODO Auto-generated method stub DatabaseHelper dbHelper = new DatabaseHelper(SQLiteDemo.this,"zhou_table"); SQLiteDatabase db = dbHelper.getReadableDatabase(); Cursor cursor = db.query("zhou_table", new String[]{"id","name"}, "id=?", new String[]{"1",""}, null, null, null); while(cursor.moveToNext()){ String name = cursor.getString(cursor.getColumnIndex("name")); System.out.println("查到的---->>>" + name); } } }); }} 实现对数据库的操作必须做到这两步：
//创建数据库对象
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteDemo.this,"zhou_table");
//调用才会真正的创建数据库
SQLiteDatabase db = dbHelper.getWritableDatabase();
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