今日总结

今天尝试安卓连接数据库

public class SQLiteDbHelp extends SQLiteOpenHelper {
private static final String SQL_CREATE_ENTRIES =
"CREATE TABLE " + BookEntry.TABLE_NAME + " (" +
BookEntry._ID + " INTEGER PRIMARY KEY," +
BookEntry.COLUMN_NAME_TITLE + " TEXT," +
BookEntry.COLUMN_NAME_PRICE + " INTEGER)";

private static final String SQL_DELETE_ENTRIES =
"DROP TABLE IF EXISTS " + BookEntry.TABLE_NAME;

public static final String DATABASE_NAME = "budaye_db.db"; //数据库名称
public static final int DATABASE_VERSION = 1;

public SQLiteDbHelp(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

/**
* 数据库创建
* @param db
*/
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(SQL_CREATE_ENTRIES);
}

/**
* 数据库版本升级
* @param db
* @param oldVersion
* @param newVersion
*/
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL(SQL_DELETE_ENTRIES);
onCreate(db);
}

/**
* 数据库版本降级
* @param db
* @param oldVersion
* @param newVersion
*/
public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
onUpgrade(db, oldVersion, newVersion);
}

}