java - 准备语句 Sqlite Android 的跟踪行

Question

我创建了一个Prepared 语句来获取我的track_id 所在的行。由于我是初学者，所以我无法理解如何从整行中一一获取值 我的代码是:

 public SQLiteStatement retrieveData(){
        SQLiteDatabase db = this.getWritableDatabase();
        SQLiteStatement stmt = db.compileStatement("Select * from tracking where track_id= ?");
        return stmt;

SQLiteStatement statement = db.retrieveData();
                statement.bindString(1,track_data.getText().toString());
                statement.execute()

就像在 SQL 数据库中一样，我们使用 ResultSet result = statements.executeQuery();如何将 statements.execute() 存储在变量中以获取行详细信息？

Answer 1

简而言之，您不使用SQLiteStatement，它仅用于/(能够)返回单行的单列:-

Represents a statement that can be executed against a database. The statement cannot return multiple rows or columns, but single value (1 x 1) result sets are supported. SQLiteStatement

相反，你可以使用:-

SQLiteDatabase db = this.getWritableDatabase();
Cursor csr = db.query("tracking",null /* all columns aka */","track_id=?",new String[]{track_data.getText().toString()},null,null,null);
while (csr.moveToNext()) {
    // and for each column value you wanted
    my_value = csr.get??????(csr.getColumnIndex(the_column_name_as_a_string)); 
    // e.g. another my_other_value = csr.get??????(csr.getColumnIndex(the_column_name_as_a_string));
}

• ??????代表许多方法，例如获取Int、获取Long……
• 参见Cursor

或者，您也可以使用 rawQuery 方法，例如:

Cursor csr = db.rawQuery("Select * from tracking where track_id= ?",new String[]{track_data.getText().toString()});