如何實現SQL Server臨時表的創建?
作者:佚名
本文主要向你介紹的是SQL Server臨時表的創建時,我們所要用到的實際操作代碼以及在實際操作中我們應注意的事項的描述。
以下的文章主要是對SQL Server臨時表的創建的實際操作步驟,以及在實際操作中我們要用到的實際應用代碼的介紹,我在一個信譽度很好的網站找到一個關于其相關內容今天拿出來供大家分享。
- Create Table #Test(a int)
如果傳來的SELECT語句不是以'select'開頭,自動修改
- If Left(Lower(Ltrim(@Select_Command)),6) <> 'select' Select @Select_Command = 'Select ' + @Select_Command
將開頭‘SELECT’去掉
- Select @Select_Command_Temp = Lower(Ltrim(@Select_Command))
- If Left(@Select_Command_Temp,6) = 'select' Select @Select_Command_Temp = Right(@Select_Command_Temp,Len(@Select_Command_Temp) - 7)
取各保留字位置,以便獲得表的列表
- Select @From_Pos = CHARINDEX(' from ',@Select_Command_Temp)
- Select @Where_Pos = CHARINDEX(' where ',@Select_Command_Temp)
- Select @Having_Pos = CHARINDEX(' having ',@Select_Command_Temp)
- Select @Groupby_Pos = CHARINDEX(' groupby ',@Select_Command_Temp)
- Select @Orderby_Pos = CHARINDEX(' orderby ',@Select_Command_Temp)
- If @Where_Pos > 0 Select @Temp_Pos = @Where_Pos
- If @Having_Pos > 0 And @Having_Pos < @Temp_Pos Select @Temp_Pos = @Having_Pos
- If @Groupby_Pos > 0 And @Groupby_Pos < @Temp_Pos Select @Temp_Pos = @Groupby_Pos
- If @Orderby_Pos > 0 And @Orderby_Pos < @Temp_Pos Select @Temp_Pos = @Orderby_Pos
SQL Server臨時表的創建中取表列表
- If @Temp_Pos > 0
- Begin
- Select @Table_List = SUBSTRING(@Select_Command_Temp,@From_Pos + 6 ,@Temp_Pos - @From_Pos - 1)
- End
- Else
- Begin
- Select @Table_List = SUBSTRING(@Select_Command_Temp,@From_Pos + 6 ,Len(@Select_Command_Temp) - @From_Pos - 1)
- End
- Select @Column_Syntax = ''
只列出欄位
- Select @Select_Command_Temp = Left(@Select_Command_Temp,@From_Pos - 1)
- While Len(@Select_Command_Temp) > 0
- Begin
取逗號位置
- Select @Temp_Pos = CHARINDEX(',',@Select_Command_Temp)
初次取欄位名稱
- If @Temp_Pos > 0
- Begin
- Select @Column_Name = Left(@Select_Command_Temp,@Temp_Pos - 1)
- End
- Else
- Begin
- Select @Column_Name = @Select_Command_Temp
- End
取表名和欄位名(可能是‘*’)
- If CHARINDEX('.',@Column_Name) > 0
- Begin
- Select @Table_Name = Left(@Column_Name,CHARINDEX('.',@Column_Name) - 1)
- Select @Column_Name = Right(@Column_Name,Len(@Column_Name) - CHARINDEX('.',@Column_Name))
- End
- Else
- Begin
- Select @Table_Name = @Table_List
- End
欄位出現'*'
- If CHARINDEX('*',@Column_Name) > 0
- Begin
- Select @Column_Name = ''
- Select @Loop_Seq = 1
SQL Server臨時表的創建中我們要取欄位個數
- Select @Column_Count = Count(*)
- From SysColumns
- Where Id = Object_Id(@Table_name)
- While @Loop_Seq <= @Column_Count
- Begin
取欄位名稱,欄位類型,長度,精度,小數位
- Select @Column_Name_Temp = SysColumns.Name,
- @Column_Type_Temp = Lower(SysTypes.Name),
- @Column_Length_Temp = SysColumns.Length,
- @Column_Xprec_Temp = SysColumns.Xprec,
- @Column_Xscale_Temp = SysColumns.Xscale
- From SysColumns,SysTypes
- Where SysColumns.Id = Object_Id(@Table_name) And
- SysColumns.Colid = @Loop_Seq And
- SysColumns.XuserType = SysTypes.XuserType
形成欄位語法表達式
- Select @Column_Syntax_Temp = Case When @Column_Type_Temp In ('datetime','image','int') Then @Column_Name_Temp + ' ' + @Column_Type_Temp
以上的相關內容就是對SQL Server臨時表的創建的介紹,望你能有所收獲。
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責任編輯:佚名
來源:
新浪博客