transactions

问题 I know MongoDB doesn't support transactions as relational databases do, but I still wonder how to achieve atomicity for several operations. Hunting around the web, I see people mentioning Transactions without Transactions. Reading through the slides, I am still not clear how to implement that with Mongoose.js. Take this code snippet for example: player.save(callback1); story.save(callback2); How do I implement callback1 and callback2 so that they either succeed together or fail together? 回答1:

问题 I have a MSSSQL stored procedure performing a distributed transaction that looks like this: SET XACT_ABORT ON; SET NOCOUNT ON; BEGIN TRY BEGIN DISTRIBUTED TRANSACTION insert into LNKSRV.INST.dbo.zz (id, val) values (1, 'a'); insert into LNKSRV.INST.dbo.zz (id, val) values (2, 'b'); COMMIT TRANSACTION END TRY BEGIN CATCH if (XACT_STATE() <> 0) BEGIN ROLLBACK TRANSACTION; END print ERROR_MESSAGE(); print ERROR_LINE(); print ERROR_SEVERITY(); END CATCH This works fine. If I add this 3rd insert

问题 I know it may sound odd but is there any way I can call my trigger on ROLLBACK event in a table? I was going through postgresql triggers documentation, there are events only for CREATE, UPDATE, DELETE and INSERT on table. My requirement is on transaction ROLLBACK my trigger will select last_id from a table and reset table sequence with value = last_id + 1; in short I want to preserve sequence values on rollback. Any kind of ideas and feed back will be appreciated guys! 回答1: You can't use a

问题 My users are uploading a csv or xls or whatever and each line is going to be an instance of a domain object I save. If any of the lines fail I want the whole thing rolled back, but I also want to return errors for any lines that will fail later. Let's make an example: Domain class: MyDomainClass{ String fieldOne BigDecimal fieldTwo } Input: ThisLineWorks,4.4 ThisLineFails,BecauseOfThis How would I also get an error, for this line as well considering the last one would have rolled back the

问题 My users are uploading a csv or xls or whatever and each line is going to be an instance of a domain object I save. If any of the lines fail I want the whole thing rolled back, but I also want to return errors for any lines that will fail later. Let's make an example: Domain class: MyDomainClass{ String fieldOne BigDecimal fieldTwo } Input: ThisLineWorks,4.4 ThisLineFails,BecauseOfThis How would I also get an error, for this line as well considering the last one would have rolled back the

问题 Does anyone have an example of the best way to begin, commit/rollback a transaction from within a CDI managed bean within a J2EE 6 container.? I have run into a particular case where the annotated approach won't work for me (I'm calling the method from another method in the same class) and I need to set the transaction boundaries manually. I would like to know what I can do in my code that would replicate the behavior of the following annotation: @TransactionAttribute(TransactionAttributeType

问题 I am developing Data Access Layer using NHibernate. It will be used in my Business Logic Layer. My application is collection of multiple other applications (ASP.NET MVC, Windows Services, Windows Forms, ASP.NET Web API) those all will use same Business Logic Layer. Business Logic Layer will access Data Access Layer. Applications will NOT access Data Access Layer directly. I am aware that I should NOT depend on implicit transaction and should include all database calls (including READ calls)

问题 First a little setup. Last week I was having trouble implementing a specific methodology that I had constructed which would allow me to manage two unique fields associated with one db.Model object. Since this isn't possible, I created a parent entity class and a child entity class, each having the key_name assigned one of the unique values. You can find my previous question located here, which includes my sample code and a general explaination of my insertion process. On my original question,

问题 This scenario using CMT is working: Stateless session bean with CMT, one method annotated with @TransactionAttribute(TransactionAttributeType.MANDATORY) . Within this method, a record is written into a RDBMS using an XA data source and plain JDBC. The stand-alone client (separate JVM, command-line Java application) is getting a UserTransaction from the application server (by JNDI lookup), starts the transaction, and calls the EJB. If the client commits the UserTransaction , the record is

问题 Is it possible with MySQL 5.5 to get the current transaction ID? Something like... BEGIN; SELECT CURRENT_XID(); -- foo ... SELECT CURRENT_XID(); -- also foo ROLLBACK; SELECT CURRENT_XID(); -- NOT foo The actual value isn't important, as long as I can get some unique identifier that will always return the same value throughout the same transaction. 回答1: Have a gander at http://dev.mysql.com/doc/refman/5.5/en/innodb-trx-table.html There is no simple function to return that information but you