Question

我第一次尝试使用临时表和MERGE语句通过C＃中的SqlCommand对象更新SQL表。我正在研究的程序旨在首先将一组非常大的记录（超过20k +）导出到Excel电子表格中。然后，用户能够搜索并替换特定值，并在他们喜欢的记录中更新尽可能多的字段。

然后我要尝试的是获取该电子表格，用它填充DataTable，然后使用DataTable使用SqlBulkCopy填充临时SQL表。

然后我使用MERGE语句更新行，如果它们仍存在于数据库中。

但是，我遇到的问题是我在ZipCodeTerritory表上的唯一约束不断被触发，并给出以下错误消息：

无法在对象'dbo.ZipCodeTerritory'中插入具有唯一索引'UQ_ChannelStateEndDateZipCodeISNULL'的重复键行。重复键值为（9，CA，94351,9999-12-31）。

这让我相信某个UPDATE语句没有被执行，或者我使用ON关键字在语句的某个部分错误地加入了表。唯一约束仅在INSERT语句期间触发，或UPDATE在ChannelCode，StateCode，ZipCode或EndDate字段中触发。我正在对IndDistrnId字段进行批量更新，并彻底检查了电子表格。

同样，这是我尝试这种技术的第一次尝试，所以任何帮助/建议将不胜感激。感谢

C＃

private static string updateCommand = "UPDATE SET Target.ChannelCode = Source.ChannelCode, Target.DrmTerrDesc = Source.DrmTerrDesc, Target.IndDistrnId = Source.IndDistrnId," +
                                            "Target.StateCode = Source.StateCode, Target.ZipCode = Source.ZipCode, Target.EndDate = Source.EndDate, Target.EffectiveDate = Source.EffectiveDate," +
                                            "Target.LastUpdateId = Source.LastUpdateId, Target.LastUpdateDate = Source.LastUpdateDate, Target.ErrorCodes = Source.ErrorCodes," +
                                            "Target.Status = Source.Status ";

//Load updates into datatable
DataTable table = LoadData(updates);

//Script to create temp table
string tmpTable =   "CREATE TABLE [dbo].[ZipCodeTerritoryTemp]( " +
                    "[ChannelCode] [char](1) NOT NULL, " +
                    "[DrmTerrDesc] [nvarchar](30) NOT NULL, " +
                    "[IndDistrnId] [char](3) NULL, " +
                    "[StateCode] [char](3) NOT NULL, " +
                    "[ZipCode] [char](9) NULL, " +
                    "[EndDate] [date] NOT NULL, " +
                    "[EffectiveDate] [date] NOT NULL, " +
                    "[LastUpdateId] [char](8) NULL, " +
                    "[LastUpdateDate] [date] NULL, " +
                    "[Id] [int] IDENTITY(1,1) NOT NULL, " +
                    "[ErrorCodes] [varchar](255) NULL, " +
                    "[Status] [char](1) NULL, " +
                    "CONSTRAINT [PK_ZipCodeTerritoryTemp] PRIMARY KEY NONCLUSTERED  " +
                "( " +
                    "[Id] ASC " +
                ")WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY] " +
                ") ON [PRIMARY]";

using (SqlConnection connection = new SqlConnection(connString))
{
    connection.Open();

    //Create temp table
    SqlCommand cmd = new SqlCommand(tmpTable, connection);
    cmd.ExecuteNonQuery();

    try
    {

        using (SqlBulkCopy bulkCopy = new SqlBulkCopy(connection))
        {
            //Write to temp table
            bulkCopy.DestinationTableName = "ZipCodeTerritoryTemp";
            bulkCopy.WriteToServer(table);

            //Merge changes in temp table with ZipCodeTerritory
            string mergeSql = "merge ZipCodeTerritory as Target " +
                                "using ZipCodeTerritoryTemp as Source " +
                                "on " +
                                "Target.Id = Source.Id " +
                                "when matched then " +
                                updateCommand + ";";

            cmd.CommandText = mergeSql;
            int results = cmd.ExecuteNonQuery();

            //Drop temp table
            cmd.CommandText = "DROP TABLE [dbo].[ZipCodeTerritoryTemp]";
            cmd.ExecuteNonQuery();
        }
    }
    catch (Exception)
    {
        throw;
    }
    finally
    {
        //Drop temp table
        SqlCommand final = new SqlCommand("DROP TABLE [dbo].[ZipCodeTerritoryTemp]", connection);
        final.ExecuteNonQuery();
    }
}

SQL

为了便于阅读，这里是我在SQL Server Management Studio中编写的MERGE语句。我将其复制到C＃中。仅供参考 - 在Management Studio中运行此语句并收到完全相同的错误消息。

MERGE INTO ZipCodeTerritory as Target
USING ZipCodeTerritoryTemp as Source
ON Target.Id = Source.Id

WHEN MATCHED THEN

UPDATE SET Target.ChannelCode = Source.ChannelCode, Target.DrmTerrDesc = Source.DrmTerrDesc, Target.IndDistrnId = Source.IndDistrnId,
    Target.StateCode = Source.StateCode, Target.ZipCode = Source.ZipCode, Target.EndDate = Source.EndDate, Target.EffectiveDate = Source.EffectiveDate,
    Target.LastUpdateId = Source.LastUpdateId, Target.LastUpdateDate = Source.LastUpdateDate, Target.ErrorCodes = Source.ErrorCodes,
    Target.Status = Source.Status;

Answer 1

问题结果是临时表中IDENTITY字段上设置的Id属性。删除后，我能够无误地运行MERGE。现在是临时表：

//Script to create temp table
string tmpTable =   "CREATE TABLE [dbo].[ZipCodeTerritoryTemp]( " +
                    "[ChannelCode] [char](1) NOT NULL, " +
                    "[DrmTerrDesc] [nvarchar](30) NOT NULL, " +
                    "[IndDistrnId] [char](3) NULL, " +
                    "[StateCode] [char](3) NOT NULL, " +
                    "[ZipCode] [char](9) NULL, " +
                    "[EndDate] [date] NOT NULL, " +
                    "[EffectiveDate] [date] NOT NULL, " +
                    "[LastUpdateId] [char](8) NULL, " +
                    "[LastUpdateDate] [date] NULL, " +
                    "[Id] [int] NOT NULL, " +               //DO NOT GIVE THE PK OF THE TEMP TABLE AN IDENTITY(1,1,) PROPRETY
                    "[ErrorCodes] [varchar](255) NULL, " +
                    "[Status] [char](1) NULL, " +
                    "CONSTRAINT [PK_ZipCodeTerritoryTemp] PRIMARY KEY NONCLUSTERED  " +
                "( " +
                    "[Id] ASC " +
                ")WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 90) ON [PRIMARY] " +
                ") ON [PRIMARY]";

通过C＃SqlCommand执行合并语句不起作用

1 个答案: