关于c＃：使用SqlBulkCopy时，在错误的列上违反了唯一约束

Unique constraint being violated on the wrong column when using SqlBulkCopy

我正在尝试使用SqlBulkCopy作为一次执行多个INSERT的方法，但出于某种原因，我在运行WriteToServer(DataTable)时遇到了唯一的约束违规。关于这个SqlException的奇怪之处在于它是这么说的。

我的表架构：

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CREATE TABLE Product (
ID INT IDENTITY (1, 1) PRIMARY KEY,
Name NVARCHAR(450) UNIQUE NOT NULL, -- Unique constraint being called
BulkInsertID NCHAR(6) -- Column the constraint is being called on
);

我能想到为什么会发生这种情况的唯一原因是因为我在DataColumn中分配列名时混淆了列名，但是我多次检查它们并且我找不到它们的任何问题。

最小，完整和可验证的例子：

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class Program
{
private static SqlConnection connection;
private static string connectionURL ="Server=ASUS-X750JA\\DIRECTORY;Database=directory;Integrated Security=True;";
private static Random _random = new Random();

public static SqlConnection openConnection()
{
connection = new SqlConnection(connectionURL);
connection.Open();
Console.WriteLine("Opened connection to DB");
return connection;
}

public static void closeConnection()
{
connection.Close();
Console.WriteLine("Closed connection to DB");
}

static void Main(string[] args)
{
List<string> productNames = new List<string>();
productNames.Add("Diamond");
productNames.Add("Gold");
productNames.Add("Silver");
productNames.Add("Platinum");
productNames.Add("Pearl");
addProducts(productNames);
}

private static void addProducts(List<string> productNames)
{
const string tableName ="Product";
DataTable table = new DataTable(tableName);

string bulkInsertID;
do
{
bulkInsertID = generateID();
} while (isDuplicateBulkInsertID(tableName, bulkInsertID));

DataColumn nameColumn = new DataColumn("Name");
nameColumn.Unique = true;
nameColumn.AllowDBNull = false;

DataColumn bulkInsertIDColumn = new DataColumn("BulkInsertID");
bulkInsertIDColumn.Unique = false;
bulkInsertIDColumn.AllowDBNull = true;

table.Columns.Add(nameColumn);
table.Columns.Add(bulkInsertIDColumn);

foreach (string productName in productNames)
{
DataRow row = table.NewRow();
row[nameColumn] = productName;
row[bulkInsertIDColumn] = bulkInsertID;
table.Rows.Add(row);
}

using (SqlConnection connection = openConnection())
{
using (SqlBulkCopy bulkCopy = new SqlBulkCopy(connection))
{
bulkCopy.DestinationTableName = table.TableName;
bulkCopy.WriteToServer(table);
}
}
}

/// <summary>
/// Generates random 6-character string but it's not like GUID so may need to check for duplicates
/// </summary>
/// <returns></returns>
public static string generateID()
{
char[] _base62chars ="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz".ToCharArray();
int length = 6;

var sb = new StringBuilder(length);

for (int i = 0; i < length; i++)
sb.Append(_base62chars[_random.Next(62)]);

return sb.ToString();
}

public static bool isDuplicateBulkInsertID(string tableName, string bulkInsertID)
{
string query = string.Format("SELECT BulkInsertID FROM {0} WHERE BulkInsertID = @bulkinsertid", tableName);
SqlCommand command = new SqlCommand(query, openConnection());
SqlParameter bulkInsertIDParam = new SqlParameter("@bulkinsertid", SqlDbType.NChar, bulkInsertID.Length);
bulkInsertIDParam.Value = bulkInsertID;

command.Parameters.Add(bulkInsertIDParam);
command.Prepare();
Task<SqlDataReader> asyncTask = command.ExecuteReaderAsync();
SqlDataReader reader = asyncTask.Result;
bool isDuplicate = reader.HasRows;

closeConnection();
return isDuplicate;
}
}

enter image description here

屏幕截图中显示的唯一约束属于Name列，但重复的键值正在发送到BulkInsertID列，我不知道为什么会抛出错误。

编辑：我刚刚更改了我的架构，使用uniqueidentifier作为BulkInsertID列并将row[bulkInsertIDColumn] = bulkInsertID更改为row[bulkInsertIDColumn] = Guid.NewGuid().ToString()。当我重新编写代码时，我发现生成的GUID已经运行但是当我查看表时，GUID位于名称列中。所以我可以得出结论，这不是服务器问题，而是程序中的问题。