c# - 结构化类型必须至少有一个字段 c#

Question

我真正想做的是将一个字符串数组发送到 SQL Server。我正在使用 SQL Server 2008。

这可以标记为重复，但在实现来自 stactoverflow 的解决方案时我面临着另一个问题

链接:How to pass an array into a SQL Server stored procedure

这是我的 C# 和存储过程代码

C#代码:

string[] str = new string[] {"s" , "a" , "k"};

DataTable dt = new DataTable();
dt.Columns.Add("names");

foreach (string item in str)
{
    dt.Rows.Add(item);
}

foreach (DataRow r in dt.Rows)
{
    Console.WriteLine(r["names"].ToString());
}

DataTable tvp = new DataTable();

SqlConnection conn = new SqlConnection("Data Source=SHZAK;Initial Catalog=synchroniztionTesing;Integrated Security=True");
conn.Open();

using (conn)
{
    SqlCommand cmd = new SqlCommand("strpdPassAnStringArray", conn);
    cmd.CommandType = CommandType.StoredProcedure;

    SqlParameter tvparam = cmd.Parameters.AddWithValue("@List", tvp);
    tvparam.SqlDbType = SqlDbType.Structured;

    cmd.ExecuteScalar();
}

在创建存储过程之前，我创建了一个自定义类型:

CREATE TYPE dbo.arrayOfNames
AS TABLE
(
  name  nvarchar(max)
);

存储过程代码:

CREATE PROCEDURE [dbo].[strpdPassAnStringArray]
      @List AS dbo.arrayOfNames READONLY
AS
BEGIN
    SET NOCOUNT ON;

    SELECT name FROM @List; 
END

但在应用程序代码中它引发了这个异常:

There are not enough fields in the Structured type. Structured types must have at least one field.

在线

cmd.ExecuteScalar();

Answer 1

回答:

我问这个问题太蠢了，但至少现在我知道是什么导致了这个异常

感谢@Gusman

如果您的 DataTable 是空的，就像我的情况一样，可以引发此异常

        string[] str = new string[] {"sheraz" , "ahmed" , "khan"};
        DataTable tvp = new DataTable();


        tvp.Columns.Add("names");
        foreach (string item in str)
        {
            tvp.Rows.Add(item);
        }

        foreach (DataRow r in tvp.Rows)
        {
            Console.WriteLine(r["names"].ToString());
        }

        SqlConnection conn = new SqlConnection("Data Source=SHZAK;Initial Catalog=synchroniztionTesing;Integrated Security=True");
        conn.Open();

        using (conn)
        {
            SqlCommand cmd = new SqlCommand("strpdPassAnStringArray", conn);
            cmd.CommandType = CommandType.StoredProcedure;
            SqlParameter tvparam = cmd.Parameters.AddWithValue("@List", tvp);
            tvparam.SqlDbType = SqlDbType.Structured;
            cmd.ExecuteScalar();
        }