错误 "Insufficient result space to convert uniqueidentifier value to char."

Question

Table 用于插入：

CREATE TABLE [dbo].[CcureMessage] 
(
      [CcureMessageId] [UNIQUEIDENTIFIER] NOT NULL,
      [Event] [VARCHAR](20) NULL,
      [Type] [VARCHAR](20) NULL,
      [Message] [VARCHAR](MAX) NOT NULL,
      [Xml] [VARCHAR](4000) NOT NULL,

      CONSTRAINT [PK_CcureMessage] 
          PRIMARY KEY CLUSTERED ([CcureMessageId] ASC)
                      WITH (STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF)  ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO

ALTER TABLE [dbo].[CcureMessage] 
    ADD CONSTRAINT [DF_CcureMessage_CcureMessageId]  
        DEFAULT (NEWID()) FOR [CcureMessageId]
GO

我让 PK table 有一个默认值，这样我就根本不会传递 GUID，但似乎我仍然收到与 GUID 相关的错误。

插入通过 SSMS 正常工作的命令：

INSERT INTO CcureMessage (Event, Type, Message, Xml) 
VALUES ('event 3', 'type 3', 'big json 3', 'xml-ish');

C#代码：

public void DoInsert(Message msg)
{
    // hard-coding this to set test values
    TopicMessage tm = new TopicMessage();
    tm.Event = "event 1";
    tm.Type = "Type 1";
    tm.Message = "json data message";
    tm.Xml = "xml data goes here";

    string connString = set to correct value;

    string sql = "INSERT INTO CcureMessage (Event, Type, Message, Xml) VALUES (@Event, @Type, @Message, @Xml)";

    using (SqlConnection conn = new SqlConnection(connString))
    {
        conn.Open();
        SqlCommand cmd = new SqlCommand(sql, conn);
        cmd.CommandType = System.Data.CommandType.Text;

        SqlParameter eventParm = new SqlParameter("@Event", tm.CcureMessageId);
        SqlParameter typeParm = new SqlParameter("@Type", tm.Type);
        SqlParameter msgParm = new SqlParameter("@Message", tm.Message);
        SqlParameter xmlParm = new SqlParameter("@Xml", tm.Xml);
        cmd.Parameters.Add(eventParm);
        cmd.Parameters.Add(typeParm);
        cmd.Parameters.Add(msgParm);
        cmd.Parameters.Add(xmlParm);

        cmd.ExecuteNonQuery();
    }
}

运行这会导致错误

Insufficient result space to convert uniqueidentifier value to char

Answer 1

问题似乎是您将 guid 传递给代码中的 varchar 列

 SqlParameter eventParm = new SqlParameter("@Event", tm.CcureMessageId);

应该是：

SqlParameter eventParm = new SqlParameter("@Event", tm.Event);

Answer 2

就我而言，我没有在 C# 代码中使用 guid 并收到此错误。所以追溯到存储过程，我发现错误直接来自那里。

我将其追溯到我在 GUID 字段上运行的转换，如下所示：

CONVERT(varchar(13), guid)

我以为它只会截断字段值。所以我必须执行以下操作：

CONVERT(varchar(13), CONVERT(varchar(36), guid))

错误 "Insufficient result space to convert uniqueidentifier value to char."

Error "Insufficient result space to convert uniqueidentifier value to char."

c#

sql-server

guid

ado

uniqueidentifier