SQL Server推薦使用 SET 而不是 SELECT 對變數進行賦值。當運算式返回一個值並對一個變數進行賦值時,推薦使用 SET 方法。下表列出 SET 與 SELECT 的區別。請特別注意紅色部分。 setselect同時對多個變數同時賦值不支援支援運算式返回多個值時出錯將返回的最後一個值賦給變數運算式未傳回值變數被賦null值變數保持原值下面以具體樣本來說明問題:create table chinadba1(userid int ,addr
手工實現差異備份的步驟字元型:1、恢複當前庫;alter database 當前庫 set RECOVERY FULL--2、建表cmd;create table cmd (a image)--3、備份當前庫到D:\cmd1;backup log 當前庫 to disk = 'D:\cmd1' with init--4、插入一句話代碼到建立的表cmd;insert into cmd (a) values
複製代碼 代碼如下: using System.Data; using System.Diagnostics; using System.Data.SqlClient; string connectionString = "Data Source=HG-J3EJJ9LSW5PY;Initial Catalog=Test;User ID=sa;password=hg"; DataTable dataTable = sql_.select_datagrid(" select a from
1.如果有ID欄位,就是具有唯一性的欄位 複製代碼 代碼如下: delect table where id not in ( select max(id) from table group by col1,col2,col3... ) group by 子句後跟的欄位就是你用來判斷重複的條件,如只有col1,那麼只要col1欄位內容相同即表示記錄相同。 2. 如果是判斷所有欄位也可以這樣 複製代碼 代碼如下: select * into #aa from table group by id1,
Liwu_Items表,CreateTime列建立叢集索引 第一種,sqlserver2005特有的分頁文法 複製代碼 代碼如下: declare @page int declare @pagesize int set @page = 2 set @pagesize = 12 SET STATISTICS IO on SELECT a.* FROM ( SELECT ROW_NUMBER() OVER (ORDER BY b.CreateTime DESC) AS [ROW_NUMBER],
複製代碼 代碼如下: USE TestDB declare @conversation uniqueidentifier while exists (select 1 from sys.transmission_queue ) begin set @conversation = (select top 1 conversation_handle from sys.transmission_queue ) end conversation @conversation with cleanup
複製代碼 代碼如下: --代碼一DECLARE @cc INT SELECT NewsId,ROW_NUMBER() OVER(ORDER BY SortNum DESC) AS RowIndex INTO #tb FROM news WITH(NOLOCK) WHERE NewsTypeId=@NewsTypeId AND IsShow=1 SET @cc = @@ROWCOUNT SELECT n.* FROM news AS n WITH(NOLOCK), #tb As t WHERE