将表的列条目传输到另一个表的行的最佳方法

Question

我必须编写一个程序，它在Visual Studio 2010 C＃和SQL Server 2012中的上述限制下将数据从表传输到表。 问题是找到一个高效的算法来做到这一点，因为表很长

    private static void fillRows()
    {
        //i have
        List<String> rows; // a list with table1 names (a,b,c,d,e...)
        List<String> columnList; //list with table2 columnNames (a#mm,b#cm,c#m...)

        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            using (var command = connection.CreateCommand())
            {

            }
        }
    }

Answer 1

您可以旋转表格或结果集

more details

Answer 2

WITH NameValue AS (
    SELECT [Name]
          ,CONVERT(float, StringValue) AS NumericValue
          ,Unit
    FROM Table1
         CROSS APPLY (
             SELECT CHARINDEX(' ', [Value]) AS SpacePosition
         ) AS CA1
         CROSS APPLY (
             SELECT SUBSTRING([Value], 1, SpacePosition - 1) AS StringValue
                   ,SUBSTRING([Value], SpacePosition + 1, LEN([Value]) - SpacePosition - 1) AS Unit
         ) AS CA2
)
,NumberedNameValue AS (
    SELECT [Name]
          ,NumericValue
          ,Unit
          ,ROW_NUMBER() OVER (PARTITION BY [Name], Unit ORDER BY [Name]) AS RowNumber
    FROM NameValue
)
INSERT INTO Table2 (
    [ID], [a#mm], [b#cm], [c#m], [d#ml], [e#l], [f#dm],
)
SELECT RowNumber
      ,MAX(CASE WHEN [Name] = 'a' AND Unit = 'mm' THEN NumericValue ELSE 0 END)
      ,MAX(CASE WHEN [Name] = 'b' AND Unit = 'cm' THEN NumericValue ELSE 0 END)
      ,MAX(CASE WHEN [Name] = 'c' AND Unit = 'm' THEN NumericValue ELSE 0 END)
      ,MAX(CASE WHEN [Name] = 'd' AND Unit = 'ml' THEN NumericValue ELSE 0 END)
      ,MAX(CASE WHEN [Name] = 'e' AND Unit = 'l' THEN NumericValue ELSE 0 END)
      ,MAX(CASE WHEN [Name] = 'f' AND Unit = 'dm' THEN NumericValue ELSE 0 END)
FROM NumberedNameValue
GROUP BY RowNumber       

Answer 3

我不知道如何使用参数化查询来处理它，但它可以正常工作

    private static void fillRows(List<String> columnList, String SOURCE_TABLE, String TARGET_TABLE, String COLUMN_NAME, String COLUMN_VALUE)
    {
        Console.WriteLine("Start filling");
        try
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                connection.Open();
                string selectSql = "SELECT " + COLUMN_NAME + "," + COLUMN_VALUE + " FROM " + SOURCE_TABLE;

                SqlDataAdapter dataAdapter = new SqlDataAdapter(selectSql, connection);
                DataTable dataTable = new DataTable("cache");
                dataAdapter.Fill(dataTable);

                //Set ID
                int ID = 1;
                string insertSql = "INSERT INTO " + TARGET_TABLE + " VALUES ('" + ID + "',";
                StringBuilder sbInsertSQL = new StringBuilder();
                sbInsertSQL.Append(insertSql);


                int count = 0;
                foreach (DataRow row in dataTable.Rows)
                {
                    if (count == columnList.Count)
                    {
                        count = 0;
                        sbInsertSQL.Length--; //remove ','
                        sbInsertSQL.Append(");"); //complete command

                        SqlCommand sqlCmd = new SqlCommand(sbInsertSQL.ToString(), connection);

                        sqlCmd.ExecuteNonQuery(); //Insert row

                        //reset 
                        sbInsertSQL.Clear();
                        ID++;
                        sbInsertSQL.Append("INSERT INTO " + TARGET_TABLE + " VALUES ('" + ID + "',");
                    }

                    //make sure, connecting correct
                    if (row[0].ToString().Equals(columnList[count].Split('#')[0])) //split off the unit
                    {
                        sbInsertSQL.Append("'" + tools.withoutUnit(row[1].ToString()) + "',");
                        count++;
                    }      
                }
                connection.Close();
            }
        }

        catch (Exception ex)
        {
            Console.WriteLine(ex);
            Console.ReadLine();
        }
    }