Android SQLite(2)如何判断表是否已经存在

在sql语句中用 if not exists

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();
    }