Android学习笔记_SQLite的使用
SQLite使用方法
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){
this(context,name,VERSION);
}
public DatabaseHelper(Context context,String name,int version){
this(context,name,null,version);
}
public void onCreate(SQLiteDatabase db){
db.execSQL("create table user(id int,name varchar(20))");
System.out.println("create a Database");
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
System.out.println("update a Database");
}
}
public class SQLiteActivity extends Activity{
class UpdateListener implements OnClickListener{
public void onClick(View v){
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db",2);
SQLiteDatabase db= dbHelper.getReadableDatabase();
}
}
class InsertListener implements OnClickListener{
public void onClick(View v){
ContentValues values=new ContentValues();
values.put("id",1);
values.put("name","zhangsan");
DatabaseHelper dbHelper=new DatabaseHelper(SQLiteActivity.this,"test_mars_db");
SQLiteDatabase db= dbHelper.getWriteableDatabase();
db.insert("user",null,values);
}
}
class UpdateRecordListener implements OnClickListener{
public void onClick(View v){
DatabaseHelper dbHelper = new DatabaseHelper(SQLiteActivity.this,"test_mars_db");
SQLiteDatabase db = dbHelper.getWriteableDatabase();
ContentValues values = new ContentValus();
values.put("name","zhangsanfeng");
db.update("user",values,"id=?",new String[]{"1"});
}
}
class QueryListener implements OnClickListener{
public void onClick(){
DatabaseHelper dbHelper=new DatabaseHelper(SQLiteActivity.this,"test_mars_db");
SQLiteDatabase db= dbHelper.getWriteableDatabase();
Cursor cursor = db.query("user",new String[]{"id","name"},"id=?");
while(cursor.moveToNext()){
String name=cursor.getString(cursor.getColumnIndex("name"));
System.out.println("query----->"+name);
}
}
}
}
