使用 SqlBulkCopy 时未（始终）强制执行约束

Question

在我们的数据库表中，我们使用两个唯一的非聚集索引来创建跨四个字段的唯一约束。我们使用两个，因为其中一个字段，ZipCode 是一个可为空的字段。如果表中存在一条记录，该记录具有 ZipCode 的 null 条目，我们不希望出现新记录与其他三个字段匹配但已定义 ZipCode 并被添加（反之亦然）的情况。

问题是似乎使用SqlBulkCopy 没有强制执行任何约束，因为您可以添加任何您喜欢的记录，而不管表上已有什么。

在另一个程序中，我们使用Entity Framework，因为我们加载的数据量要少得多。使用 EF，这些约束可以完美地工作（它们目前正在生产中）。但是，使用 SqlBulkCopy 似乎它们被完全忽略了。

T-SQL

CREATE UNIQUE NONCLUSTERED INDEX [UQ_ChannelStateEndDateZipCodeNOTNULL] ON [dbo].[ZipCodeTerritory]
(
    [ChannelCode] ASC,
    [StateCode] ASC,
    [ZipCode] ASC,
    [EndDate] ASC
)
WHERE ([ZipCode] IS NOT NULL)
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO
CREATE UNIQUE NONCLUSTERED INDEX [UQ_ChannelStateEndDateZipCodeISNULL] ON [dbo].[ZipCodeTerritory]
(
    [ChannelCode] ASC,
    [StateCode] ASC,
    [ZipCode] ASC,
    [EndDate] ASC
)
WHERE ([ZipCode] IS NULL)
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY]
GO

C#

Dictionary<DataRow, string> faultyRows = new Dictionary<DataRow, string>();
using (SqlConnection connection = new SqlConnection(connString))
{
    //Open Database connection
    connection.Open();

    //Create transaction objects
    SqlTransaction transaction = connection.BeginTransaction();
    SqlBulkCopy bulkCopy = new SqlBulkCopy(connection, SqlBulkCopyOptions.CheckConstraints, transaction);
    bulkCopy.DestinationTableName = "ZipCodeTerritory";

    //Load data and initialize datatable
    DataTable dataTable = LoadData(inserts);
    IDataReader reader = dataTable.CreateDataReader();
    DataTable dataSchema = reader.GetSchemaTable();
    DataTable tmpDataTable = InitializeStructure();

    //Create array to hold data being transfered into tmpDataTable
    object[] values = new object[reader.FieldCount];

    while (reader.Read())
    {
        //Clear temp table for single-record use
        tmpDataTable.Rows.Clear();

        //Get data for current row
        reader.GetValues(values);

        //Load values into the temp table
        tmpDataTable.LoadDataRow(values, true);

        //Load one record at a time
        try
        {
            bulkCopy.WriteToServer(tmpDataTable);
            transaction.Commit();
        }
        catch (Exception ex)
        {
            faultyRows.Add(tmpDataTable.Rows[0], ex.Message);
        }
    }
}

编辑

我发现如果定义了ZipCode 字段，则实际上会强制执行此约束。 ChannelCode、StateCode、ZipCode、EndDate 字段的任何匹配都将导致 SqlException 具有以下 Message 属性（从我刚刚运行的特定文本中提取）：

Cannot insert duplicate key row in object 'dbo.ZipCodeTerritory' with unique index 'UQ_ChannelStateEndDateZipCodeNOTNULL'. The duplicate key value is (9, WA , 98102 , 9999-12-31)

但是，这是我唯一一次可以触发我们的两个约束之一。

Answer 1

这是由于我使用将数据从模型对象（我仍在某些地方使用实体框架）传输到DataRow 的方法而发生的。下面是我现在使用的方法。在我修复之前，ZipCode 字段在 null 时被作为空字符串放入 DataRow 列。由于这在技术上不是空字段，因此没有触发约束。

    private static DataTable LoadData(List<ZipCodeTerritory>zipCodeList, bool update = false)
    {
        DataTable dataTable = InitializeStructure();

        foreach (var zipcode in zipCodeList)
        {
            DataRow row = dataTable.NewRow();

            try
            {
                row[0] = zipcode.ChannelCode.Trim();
                row[1] = zipcode.DrmTerrDesc.Trim();
                row[2] = zipcode.IndDistrnId.Trim();
                row[3] = zipcode.StateCode.Trim();
                row[4] = (string.IsNullOrWhiteSpace(zipcode.ZipCode) ? null : zipcode.ZipCode.Trim());
                row[5] = zipcode.EndDate.Date;
                row[6] = zipcode.EffectiveDate.Date;
                row[7] = zipcode.LastUpdateId;
                row[8] = DateTime.Now.Date;
                row[10] = zipcode.ErrorCodes;
                row[11] = zipcode.Status;

                //Add the Id column if we're doing an update
                if(update) row[9] = zipcode.Id;
            }
            catch (Exception ex)
            {

            }

            dataTable.Rows.Add(row);
        }

        return dataTable;
    }