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如何獲得剛插入數(shù)據(jù)庫(kù)的記錄的ID號(hào)?
1.SQL Server 對(duì)于SQL Server 2000來(lái)說(shuō),它提供了兩個(gè)全新的函數(shù)(IDENT_CURRENT,SCOPE_IDENTITY),并且改進(jìn)了@@IDENTITY的不足.當(dāng)你插入新記錄后,可以調(diào)用函數(shù): PRINT IDENT_CURRENT('table') '這將獲得新的IDENTITY值,不管數(shù)據(jù)庫(kù)中是不是有記錄添加(這就避免了@@IDENTITY的連接限制) 或者:PRINT SCOPE_IDENTITY() '這將獲得在當(dāng)前存儲(chǔ)過(guò)程,觸發(fā)器等其他程序創(chuàng)建的最新記錄的IDENTITY值. 而全局變量@@IDENTITY有一個(gè)問(wèn)題,當(dāng)對(duì)一張表執(zhí)行insert時(shí),如果該表有觸發(fā)器程序在執(zhí)行插入操作,然后,接著在另一張表中插入記錄,這樣返回@@IDENTITY值就是第二張表的IDENTITY值。 如果你用的不是SQL Server 2000,你最好一個(gè)簡(jiǎn)單的存儲(chǔ)過(guò)程來(lái)解決這個(gè)問(wèn)題。 CREATE PROCEDURE myProc @param1 INT AS BEGIN SET NOCOUNT ON INSERT INTO someTable ( intField ) VALUES ( @param1 ) SET NOCOUNT OFF SELECT NEWID = @@IDENTITY END 在ASP中你可以這樣做: <% fakeValue = 5 set conn = Server.CreateObject("ADODB.Connection") conn.open "<conn string>" set rs = conn.execute("exec myProc @param1=" & fakeValue) response.write "New ID was " & rs(0) rs.close: set rs = nothing conn.close: set conn = nothing %>
2.Access 對(duì)于Access,你可以用下面這樣的方法: <% fakeValue = 5 set conn = Server.CreateObject("ADODB.Connection") conn.open "<conn string>" conn.execute "Insert into someTable(intField) values(" & fakeValue & ")" set rs = conn.execute("select MAX(ID) from someTable") response.write "New ID was " & rs(0) rs.close: set rs = nothing conn.close: set conn = nothing %> 然而對(duì)于多人同時(shí)向數(shù)據(jù)庫(kù)中添加數(shù)據(jù),我們就要利用記錄集的adOpenKeyset游標(biāo)來(lái)防止出錯(cuò)。例如下面的例子: <% fakeValue = 5 set conn = Server.CreateObject("ADODB.Connection") conn.open "<conn string>" set rs = Server.CreateObject("ADODB.Recordset") rs.open "select [intField] from someTable where 1=0", conn, 1, 3 rs.AddNew rs("intField") = fakeValue rs.update response.write "New ID was " & rs("id") rs.close: set rs = nothing conn.close: set conn = nothing %>
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