您可以在SQL FROM语句中使用SQLParameter吗? [英] Can you use a SQLParameter in the SQL FROM statement?

问题描述

我试图在C#中针对SQL Server数据库创建参数化查询.

I am trying to create a parameterized query in C# against a SQL server database.

代码:

        query = new StringBuilder( "SELECT @fields FROM @tables");

        using(SqlConnection connection = new SqlConnection(connection))
        {
            SqlCommand command = new SqlCommand(query.ToString(), connection);
            command.Parameters.AddWithValue("@fields", fields.ToString());
            command.Parameters.AddWithValue("@tables", tables.ToString());

            try
            {
                connection.Open();
                Int32 rowsAffected = command.ExecuteNonQuery();
                Console.WriteLine("RowsAffected: {0}", rowsAffected);
            }
            catch(Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }

奇怪的是，此操作失败，并显示消息必须声明表变量\"@ tables \".但是，正如您所看到的，它已经明确定义了.

The strange part is this fails with the message "Must declare the table variable \"@tables\". However as you can see, it's clearly been defined.

所以我的问题是:

1. 您可以传递参数来定义 FROM中的表列表 陈述?
2. 如果可以，为什么不 这个工作吗?

1. Can you pass a parameter to define the table list in the FROM statement?
2. If you can, why isn't this working?

推荐答案

SQL不支持对FROM子句进行参数化.因此，您必须使用动态SQL，或在将查询字符串提交到数据库之前创建/连接查询字符串.

SQL doesn't support the FROM clause to be parameterized. So you have to use either dynamic SQL, or create/concatenate the query string prior to submitting it to the database.

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