Sql 如何将列中的行值分组并将行转换为列？

我的要求如下：在SQL2005中使用Sql查询，如果可能的话要避免存储过程

EmpType  EmpName         Role

1             Ram        Admin

2             Raja       Admin

1             John       update

2             Tom        Admin

1             Adam       Admin

我需要一个分组的输出，按以下方式清空：

EmpType        EmpName           Admin      Update

1              Ram, John, Adam   Adam,Ram    John

2              Raja , Tom        Tom,Raja

谁能帮帮我吗

---

谢谢，

要执行此任务，您需要编写自己的包含字符串的聚合函数。下面是一个例子：

using System;
using System.Collections.Generic;
using System.Data.SqlTypes;
using System.IO;
using Microsoft.SqlServer.Server;

[Serializable]
[SqlUserDefinedAggregate(Format.UserDefined,  MaxByteSize=8000)]
public struct strconcat : IBinarySerialize{
        private List values;

        public void Init()    {
            this.values = new List();
        }

        public void Accumulate(SqlString value)    {
            this.values.Add(value.Value);
        }

        public void Merge(strconcat value)    {
            this.values.AddRange(value.values.ToArray());
        }

        public SqlString Terminate()    {
            return new SqlString(string.Join(", ", this.values.ToArray()));
        }

        public void Read(BinaryReader r)    {
            int itemCount = r.ReadInt32();
            this.values = new List(itemCount);
            for (int i = 0; i <= itemCount - 1; i++)    {
                this.values.Add(r.ReadString());
            }
        }



        public void Write(BinaryWriter w)    {
            w.Write(this.values.Count);
            foreach (string s in this.values)      {
                w.Write(s);
            }
        }
}

---

您可能还希望选中

，以执行编写自己的包含字符串的聚合函数所需的任务。下面是一个例子：

using System;
using System.Collections.Generic;
using System.Data.SqlTypes;
using System.IO;
using Microsoft.SqlServer.Server;

[Serializable]
[SqlUserDefinedAggregate(Format.UserDefined,  MaxByteSize=8000)]
public struct strconcat : IBinarySerialize{
        private List values;

        public void Init()    {
            this.values = new List();
        }

        public void Accumulate(SqlString value)    {
            this.values.Add(value.Value);
        }

        public void Merge(strconcat value)    {
            this.values.AddRange(value.values.ToArray());
        }

        public SqlString Terminate()    {
            return new SqlString(string.Join(", ", this.values.ToArray()));
        }

        public void Read(BinaryReader r)    {
            int itemCount = r.ReadInt32();
            this.values = new List(itemCount);
            for (int i = 0; i <= itemCount - 1; i++)    {
                this.values.Add(r.ReadString());
            }
        }



        public void Write(BinaryWriter w)    {
            w.Write(this.values.Count);
            foreach (string s in this.values)      {
                w.Write(s);
            }
        }
}

---

如果您不想创建额外的结构（存储过程、函数等），您可能还需要选中此项：

select 
    EmpType, 
    stuff((select ', ' + EmpName from tmp t2 where t2.EmpType = t1.EmpType 
           for xml path('')),1,2,'') EmpName,
    stuff((select ', ' + EmpName from tmp t2 where t2.EmpType = t1.EmpType and t2.Role = 'Admin' 
           for xml path('')),1,2,'') [Admin],
    stuff((select ', ' + EmpName from tmp t2 where t2.EmpType = t1.EmpType and t2.Role = 'Update' 
           for xml path('')),1,2,'') [Update]
from tmp t1
group by EmpType

---

如果您不想创建额外的结构（存储过程、函数等），这就是您需要的：

select 
    EmpType, 
    stuff((select ', ' + EmpName from tmp t2 where t2.EmpType = t1.EmpType 
           for xml path('')),1,2,'') EmpName,
    stuff((select ', ' + EmpName from tmp t2 where t2.EmpType = t1.EmpType and t2.Role = 'Admin' 
           for xml path('')),1,2,'') [Admin],
    stuff((select ', ' + EmpName from tmp t2 where t2.EmpType = t1.EmpType and t2.Role = 'Update' 
           for xml path('')),1,2,'') [Update]
from tmp t1
group by EmpType

---

这对你有帮助吗？让我们知道。这对你有帮助吗？让我们知道。