Question

所以我设置了一个应用程序来导入CSV文件。它创建了一个数据表和一个临时的sql表。代码读取CSV并将其放入数据表中，然后将其批量导入到临时表中，现在只需将其复制到生产表中即可。为了我的目的，我需要它，以便当导入.csv文件并且有空字符串时，它们将被跳过并且不在生产数据库中插入或更新，只插入/更新csv中存在的内容（除了空字符串课程）。

所以例如说我第一次去导入我只是简单地导入了以下网站信息：

PDW0033B50D3，东北办事处，246 Western Blvd

然后再说我要更新位置的地址，所以我重新导入一个只有必要字段的csv文件。

PDW0033B50D3 ,, 290 Western Blvd

现在，代码将在数据库中为空行添加第二行的空字符串，因此Northeast office将变为数据库中的空白/空字符串。我怎么做到这样，当csv中有一个空字符串时，它会通过我的sql查询跳过？

这是我的代码：

       public void btnBulkSite_click(object sender, EventArgs e)
    {
            //Save File
        if (FileUpLoad1.HasFile)
        {
            FileUpLoad1.SaveAs(@"C:\temp\" + FileUpLoad1.FileName);
            btnBulkSite.Text = "File Uploaded: " + FileUpLoad1.FileName;
        }
        else
        {
            btnBulkSite.Text = "No File Uploaded.";
        }

            //Create Temporary Table

        string TmpTable = "CREATE TABLE #TMPBULK (SERVER_ID VARCHAR(13), SITE_NAME VARCHAR(50), SITE_ADDRESS VARCHAR(50))";
            //Create DataTable
        DataTable tblcsv = new DataTable();

        tblcsv.Columns.Add(new DataColumn("SERVER_ID", typeof(string)));
        tblcsv.Columns.Add(new DataColumn("SITE_NAME", typeof(string)));
        tblcsv.Columns.Add(new DataColumn("SITE_ADDRESS", typeof(string)));



            //Read in CSV File
        System.IO.StreamReader stream = new System.IO.StreamReader(FileUpLoad1.PostedFile.InputStream);

        string ReadCSV = stream.ReadToEnd();
        foreach (string csvRow in ReadCSV.Split('\n'))
            {

                if (!string.IsNullOrEmpty(csvRow))
                {
                tblcsv.Rows.Add();
                int count = 0;

                foreach (string FileRec in csvRow.Split(','))
                {
                    tblcsv.Rows[tblcsv.Rows.Count - 1][count] = FileRec;

                    count++;
                }
            }
        }

            //SQL CON
        string conString = ConfigurationManager.ConnectionStrings["css"].ConnectionString;
        using (SqlConnection con2 = new SqlConnection(conString))
        {
            con2.Open();

            //Execute the command to make a temp table
            SqlCommand cmd = new SqlCommand(TmpTable, con2);
            cmd.ExecuteNonQuery();
            using (BulkOperation bulk = new BulkOperation(con2))

            {


                bulk.DestinationTableName = "#TMPBULK";

                bulk.BulkInsert(tblcsv);
            }

            //Copy Data from Temp Table to Prod Table
            string mergeSql = "merge into SITE_INFO as Target " +
              "using #TMPBULK as Source " +
              "on " +
              "Target.SERVER_ID=Source.SERVER_ID " +
              "and Target.SITE_NAME = Source.SITE_NAME " +
              "when matched then " +
              "update set Target.SITE_ADDRESS=Source.SITE_ADDRESS " +
              "when not matched then " +
              "insert (SERVER_ID,SITE_NAME,SITE_ADDRESS) values (Source.SERVER_ID,Source.SITE_NAME,Source.SITE_ADDRESS);";






            cmd.CommandText = mergeSql;
            cmd.ExecuteNonQuery();
            cmd.CommandText = "drop table #TMPBULK";
            cmd.ExecuteNonQuery();
        }
    }

Answer 1

尝试从

更改您的SET

update set Target.SITE_ADDRESS=Source.SITE_ADDRESS

到

update set Target.SITE_ADDRESS=IF(Source.SITE_ADDRESS='',Target.SITE_ADDRESS,Source.SITE_ADDRESS)

和SITE_NAME类似。

MySQL跳过空字符串查询？

1 个答案: