java - Difference in rolling back a statement and a transaction in JPA -

-

jpa query javadoc (see http://docs.oracle.com/javaee/6/api/javax/persistence/query.html#executeupdate()) says

int executeupdate() execute update or delete statement.  returns: number of entities updated or deleted  throws:  illegalstateexception - if called java persistence query language select statement or criteria query  transactionrequiredexception - if there no transaction  querytimeoutexception - if statement execution exceeds    query timeout value set , statement rolled  persistenceexception - if query execution exceeds    query timeout value set , transaction rolled

what's difference between rolling statemente , transaction? mean, rolling transaction pretty obvious, set transaction rollback , operations undone. if statement rolled (since it's update/delete/insert operation), won't whole transaction rolled in situation?

was querytimeoutexception designed caught , allow user retry on timeout without affecting transaction?

[a querytimeoutexception is] thrown persistence provider when query times out , statement rolled back. current transaction, if 1 active, not marked rollback. [querytimeoutexception]

the querytimeoutexception specialization of persistenceexception.

[a persistenceexception is] thrown persistence provider when problem occurs. instances of persistenceexception except instances of noresultexception, nonuniqueresultexception, locktimeoutexception, , querytimeoutexception cause current transaction, if 1 active , persistence context has been joined it, marked rollback. [persistenceexception]

therefore if query times out don't matter not cause rollback of transaction default. that's why have explicitly. example if want rollback transaction regardless persistenceexception occurs.

catch(persistenceexception e) { ... tx.rollback(); ... }

but makes sense continue transaction statement not successful , querytimeoutexception occurs.

an example scenario time out during execution of statement persist additional log record. depending on use case time out of executing log statement not critical otherwise it's critical if core business process example persisting order times out. therefore don't want failed log statement affect persisting of order. on other hand if persisting of order fails persisting of log record should roll backed. can decide query time out should cause rollback.

a schematically example be

... try {     ...     querynoncritical.execute(...); } catch(querytimeoutexception e) {     // not critical move on     ... } ... try {     ...     querycritical.execute(...); } catch(querytimeoutexception e) {     ...     tx.rollback();     ... } ...

Comments

Post a Comment

Popular posts from this blog

ios - RestKit 0.20 — CoreData: error: Failed to call designated initializer on NSManagedObject class (again) -

-
this error has shown on many times, seems. prominent answer issue seems restkit 0.20 — coredata: error: failed call designated initializer on nsmanagedobject class however, solution posted doesn't work me. let's start beginning: i want upload file server. want parse response make sure uploaded. if not, try again later. model has boolean variable called nsnumber *senttoserver purpose (in coredata, bool saved nsnumber ) . because don't know whether sending going successful, save entity coredata model first before sending via restkit. when post request successful, server returns json string this: {"id":14,"created":true} notice that, of course, id not set on coredata model yet, both id , created new informations model. here's model: @interface recording : nsmanagedobject @property (nonatomic, retain) nsstring * audiofilepath; @property (nonatomic, retain) nsdate * createdat; @property (nonatomic, retain) nsstring * deviceid; @...
Read more

java - Digest auth with Spring Security using javaconfig -

-
so i'm trying create digest authentication spring following documentation trying translate xml "requirements" in java requirements. let's have xml in docs: <bean id="digestfilter" class= "org.springframework.security.web.authentication.www.digestauthenticationfilter"> <property name="userdetailsservice" ref="jdbcdaoimpl"/> <property name="authenticationentrypoint" ref="digestentrypoint"/> <property name="usercache" ref="usercache"/> </bean> <bean id="digestentrypoint" class= "org.springframework.security.web.authentication.www.digestauthenticationentrypoint"> <property name="realmname" value="contacts realm via digest authentication"/> <property name="key" value="acegi"/> <property name="noncevalidityseconds" value="10"/> </b...
Read more

laravel - PDOException in Connector.php line 55: SQLSTATE[HY000] [1045] Access denied for user 'root'@'localhost' (using password: YES) -

-
my .env: app_env=local app_debug=true app_key=myappkey app_url=http://localhost db_connection=mysql db_host=localhost db_port=3306 db_database=gestiontaller db_username=root db_password='root' cache_driver=file session_driver=file queue_driver=sync redis_host=127.0.0.1 redis_password=null redis_port=6379 mail_driver=smtp mail_host=mailtrap.io mail_port=2525 mail_username=null mail_password=null mail_encryption=null i've tried password ", ' , without, restarting server every time. i've tried changing localhost 172.0.0.1. yes, password correct, running mysql -u root -p introducing password root in prompt can go mysql. users table: +------------------+-----------+ | user | host | +------------------+-----------+ | debian-sys-maint | localhost | | mysql.sys | localhost | | root | localhost | | root1 | localhost | +------------------+-----------+ i've added homestead.yaml this: database_port: 3306 ...
Read more