如何从一列插入多行 [英] How to Insert Multiple Row from one Column
问题描述
我想在一列中插入多行。
I want to insert multiple rows into one column.
对于这样的POS系统。
For my POS system like this.
表 A
:
Transaction ID| Item Code|Qty|Total|Transaction Date|
-----------------------------------------------------
00001 | Item 1 |3 |100 |12/07/2014 |
00001 | Item 2 |2 |50 |12/07/2014 |
00001 | Item 3 |1 |150 |12/07/2014 |
此后,我想在表格中看到它
After that I want to see this in my table
Transaction ID|Item Code |Total of Qty|Total of Price|Transaction Date|
-----------------------------------------------------------------------------------
00001 |Item 1, Item 2, Item 3| 6 | 150 | 12/07/2014 |
推荐答案
确实没有内置的concat函数在SQL Server中,我怀疑会有这样的情况。原因是创建 CLR用户定义的聚合非常容易。实际上,MSDN上已经有这样的例子。您可以在这里找到创建 GROUP_CONCAT
函数所需的所有内容-字符串实用程序功能。
It is true there is no build-in concat function in SQL Server and I doubt there will be such. The reason is it is very easy to create a CLR User-Defined Aggregates. Actually, there is already such example on MSDN. Everything you need to create a GROUP_CONCAT
function can be found here - String Utility Functions.
基本上,您需要执行以下步骤:
Basically, you need to follow the steps below:
-
启用
CLR
集成:
sp_configure 'clr enabled', 1
GO
RECONFIGURE
GO
创建以下C#类并构建 .dll
:
[Serializable]
[Microsoft.SqlServer.Server.SqlUserDefinedAggregate(
Microsoft.SqlServer.Server.Format.UserDefined, //use clr serialization to serialize the intermediate result
IsInvariantToNulls = true,//optimizer property
IsInvariantToDuplicates = false,//optimizer property
IsInvariantToOrder = false,//optimizer property
MaxByteSize = 8000)] //maximum size in bytes of persisted value
public class Concatenate : Microsoft.SqlServer.Server.IBinarySerialize
{
/// <summary>
/// The variable that holds the intermediate result of the concatenation
/// </summary>
private StringBuilder intermediateResult;
/// <summary>
/// Initialize the internal data structures
/// </summary>
public void Init()
{
intermediateResult = new StringBuilder();
}
/// <summary>
/// Accumulate the next value, nop if the value is null
/// </summary>
/// <param name="value"></param>
public void Accumulate(SqlString value)
{
if (value.IsNull)
{
return;
}
intermediateResult.Append(value.Value).Append(',');
}
/// <summary>
/// Merge the partially computed aggregate with this aggregate.
/// </summary>
/// <param name="other"></param>
public void Merge(Concatenate other)
{
intermediateResult.Append(other.intermediateResult);
}
/// <summary>
/// Called at the end of aggregation, to return the results of the aggregation
/// </summary>
/// <returns></returns>
public SqlString Terminate()
{
string output = string.Empty;
//delete the trailing comma, if any
if (intermediateResult != null && intermediateResult.Length > 0)
output = intermediateResult.ToString(0, intermediateResult.Length - 1);
return new SqlString(output);
}
public void Read(BinaryReader r)
{
if (r == null) throw new ArgumentNullException("r");
intermediateResult = new StringBuilder(r.ReadString());
}
public void Write(BinaryWriter w)
{
if (w == null) throw new ArgumentNullException("w");
w.Write(intermediateResult.ToString());
}
}
部署程序集并创建函数:
Deploy the assembly and create your function:
DECLARE @SamplePath nvarchar(1024)
SET @SamplePath = 'C:\MySample\'
CREATE ASSEMBLY [StringUtils]
FROM @SamplePath + 'StringUtils.dll'
WITH permission_set = Safe;
GO
CREATE AGGREGATE [dbo].[Concatenate](@input nvarchar(4000))
RETURNS nvarchar(4000)
EXTERNAL NAME [StringUtils].[Concatenate];
GO
然后您可以使用此函数可以作为任何标准聚合函数使用:
Then you can use this function as any standard aggregate function:
SELECT TransactionID, [dbo].Concatenate(ItemCode) AS ItemCodes,
SUM(Qty) AS TotalofQty, SUM(Total) AS TotalPrice, TransactionDate
FROM TableA
GROUP BY TransactionID, TransactionDate;
注意,我已经知道 CLR
集成多年,但几个月前才开始使用它。当处理大量数据时,性能差异很大。
Note, I have known about CLR
integration for years, but started to use it few months ago. The performance difference is huge when you are working with large collections of data.
这篇关于如何从一列插入多行的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!