Question

我将用户定义的表类型传递给存储过程。但它会抛出错误，因为“从对象类型System.Collections.Generic.List`1到已知的托管提供程序本机类型不存在映射。”

UserDefinedTableType:
CREATE TYPE UserQueryAttachmentList AS TABLE 
(
[UserQueryId] NVARCHAR(50),
[AttachmentPath] NVARCHAR(200),
[AttachmentName]  NVARCHAR(200),
[AttachmentFor] NVARCHAR(50),
[CreatedBy] NVARCHAR(50) 
);

Stored Procedure:
CREATE PROCEDURE PROC_UserQueryAttachment_Insert
(
@Table UserQueryAttachmentList READONLY
)
AS
BEGIN

INSERT INTO dbo.[UserQueryAttachments]
(
    UserQueryId,
    AttachmentPath,
    AttachmentName,
    AttachmentFor,
    CreatedBy,
    CreatedDate
)
SELECT
    UserQueryId,
    AttachmentPath,
    AttachmentName,
    AttachmentFor,
    CreatedBy,
    GETDATE()
FROM
    @Table T

END

C#:
public override bool SaveUserQueryAttachment(List<UserQueryAttachmentToCreate> fileList)
    {

        try
        {
            this.ExecuteStoredProcedureOrQuery<UserQueryAttachmentToCreate>("PROC_UserQueryAttachment_Insert", CommandType.StoredProcedure,
                new SqlParameter("@Table", fileList)
                );
            return true;

        }
        catch (Exception ex)
        {
            return false;
        }
    }

请指导我这个错误发生的原因？

Answer 1

对象列表无法直接传递给SQL Server。尝试传递这样的DataTable（代码未选中）：

public override bool SaveUserQueryAttachment(List<UserQueryAttachmentToCreate> fileList)
{
    // TODO: open a SQL connection here 

    using (SqlCommand cmd = new SqlCommand("exec PROC_UserQueryAttachment_Insert @table", connection))
    {
        using (var table = new DataTable()) 
        {
            table.Columns.Add("UserQueryId", typeof(string));
            table.Columns.Add("AttachmentPath", typeof(string));
            table.Columns.Add("AttachmentName", typeof(string));
            table.Columns.Add("AttachmentFor", typeof(string));
            table.Columns.Add("CreatedBy", typeof(string));

            table.Rows.Add(fileList.ToArray());

            var list = new SqlParameter("@table", SqlDbType.Structured);
            list.TypeName = "dbo.UserQueryAttachmentList";
            list.Value = table;

            cmd.Parameters.Add(list);
            cmd.ExecuteReader();
         }
    }

    // TODO: close the SQL connection
}

存储过程中的UDT类型：错误 - 从对象类型System.Collections.Generic.List`1到已知的托管提供程序本机类型不存在映射

1 个答案: