identity

问题 I have an ADO.NET DataTable with about 100,000 records. In this table there is a column xyID which has no values in it, because the column is an auto-generated IDENTITY in my SQL Server database. I need to retrieve the generated IDs for other processes. I am looking for a way to bulk copy this DataTable into the SQL Server database, and within the same "step" to "fill" my DataTable with the generated IDs. How can I retrieve the identity values of records inserted into a table using the

问题 I know I can do a bulk insert into my table with an identity column by not specifying the SqlBulkCopyOptions.KeepIdentity as mentioned here. What I would like to be able to do is get the identity values that the server generates and put them in my datatable, or even a list. I saw this post, but I want my code to be general, and I can't have a version column in all my tables. Any suggestions are much appreciated. Here is my code: public void BulkInsert(DataTable dataTable, string

问题 On our Windows 2008 R2 server I have a site running under the default ASP.NET v4.0 application pool. The identity of ASP.NET v.4.0 app pool is set to "ApplicationPoolIdentity" (I guess this is default). How do I grant this identity access to read from a custom folder within my site. I have tried "Application Pool Identity" and "ApplicationPoolIdentity" but both gives me: An object named "Application Pool Identity" cannot be found. Bonus question = should I instead forget about all this and

问题 On our Windows 2008 R2 server I have a site running under the default ASP.NET v4.0 application pool. The identity of ASP.NET v.4.0 app pool is set to "ApplicationPoolIdentity" (I guess this is default). How do I grant this identity access to read from a custom folder within my site. I have tried "Application Pool Identity" and "ApplicationPoolIdentity" but both gives me: An object named "Application Pool Identity" cannot be found. Bonus question = should I instead forget about all this and

问题 In SQL Server 2000 or above is there anyway to handle an auto generated primary key (identity) column when using a statement like the following? Insert Into TableName Values(?, ?, ?) My goal is to NOT use the column names at all. 回答1: By default, if you have an identity column, you do not need to specify it in the VALUES section. If your table is: ID NAME ADDRESS Then you can do: INSERT INTO MyTbl VALUES ('Joe', '123 State Street, Boston, MA') This will auto-generate the ID for you, and you

问题 I'm in the process of designing a fairly complex system. One of our primary concerns is supporting SQL Server peer-to-peer replication. The idea is to support several geographically separated nodes. A secondary concern has been using a modern ORM in the middle tier. Our first choice has always been Entity Framework, mainly because the developers like to work with it. (They love the LiNQ support.) So here's the problem: With peer-to-peer replication in mind, I settled on using uniqueidentifier

问题 I'm trying to insert a row and get back the new row's identity with something like this: INSERT INTO blah....; SELECT @@IDENTITY as NewID; I'm trying to execute both statements with a single invocation of a DbCommand object in C#... it doesn't seem work or I've got something wrong. I've read that Compact Edition doesn't support executing multiple statements in a batch... but I also found this: If you want to run multiple queries simultaneously, you must include a new line character for each

问题 I am using ASP.NET MVC5 and Identity 2.0 (beta). It is possible for users to change the username? I am trying using UserManager.UpdateAsync method throws an exception. Regrads, Fran. 回答1: Yes it is possible using the UpdateAsync method but you need to ensure that you update both the email and username fields. var user = userManager.FindById(userId); user.Email = email; user.UserName = email; var updateResult = await userManager.UpdateAsync(user); This method works successfully for me 回答2:

问题 What happen when SQL Server 2005 happen to reach the maximum for an IDENTITY column? Does it start from the beginning and start refilling the gap? What is the behavior of SQL Server 2005 when it happen? 回答1: You will get an overflow error when the maximum value is reached . If you use the bigint datatype with a maximum value of 9,223,372,036,854,775,807 this will most likely never be the case. The error message you will get, will look like this: Msg 220, Level 16, State 2, Line 10 Arithmetic

问题 What happen when SQL Server 2005 happen to reach the maximum for an IDENTITY column? Does it start from the beginning and start refilling the gap? What is the behavior of SQL Server 2005 when it happen? 回答1: You will get an overflow error when the maximum value is reached . If you use the bigint datatype with a maximum value of 9,223,372,036,854,775,807 this will most likely never be the case. The error message you will get, will look like this: Msg 220, Level 16, State 2, Line 10 Arithmetic