Hi Vladislav, Back when created this class , I thought something along the lines of usual OO technique - single interface, 2 different concrete implementations classes . Connection.prepareStatement() would serve then as a factory method -dependent on useServerPrepStmt connection parameter it would create either MySQLPreparedStatement or MySQLServerSidePreparedStatement I agree with your concerns and initially it was coded in the above way. The answer which you gave : This is easy to explan and can also be easily found with bzr, or Launchpad. The file was added in revision 424 http://bazaar.launchpad.net/~maria-captains/mariadb-java-client/trunk/revisi... .. The comment says "CONJ21- allow ResultSetMetaData to be retrieved from preparedStatement, before statement is executed. Fix is using server-side prepared statement functionality - prepare command will return result set metadata among other information. Introduce MySQLServerSidePreparedStateme nt class, which in the future will be able to provide full-featured PreparedStatement functionality, using server side prepared statements internally." This is the fix for the bug https://mariadb.atlassian.net/browse/CONJ-21 , to allow users to retrieve ResultSetMetadata priorto /without the execution of statement. This is only possible with server-side "prepare", no other way around it The class was meant to be expanded in the future, as the comment said. Thanks for the above .Neither me nor my mentors were aware about this I guess and that's the reason we decided to add the useServerPrepStmts feature using MySQLPreparedStatement. I will discuss with my mentors and continue posting on the steps being taken. Thanks & Regards Puneet. On Sun, Jun 8, 2014 at 4:08 PM, Vladislav Vaintroub <wlad@montyprogram.com> wrote:
-----Original Message----- From: Puneet Dewan [mailto:puneetd30@gmail.com] Sent: Sonntag, 8. Juni 2014 00:37 To: Vladislav Vaintroub Cc: maria-developers@lists.launchpad.net Subject: Re: [Maria-developers] Java Connector Coding till 5th June
Hi Puneet,
The advantages of creating a new class MySQLServerSidePreparedStatement will be a clear separation of concerns. :)
Back when created this class , I thought something along the lines of usual OO technique - single interface, 2 different concrete implementations classes . Connection.prepareStatement()would serve then as a factory method -dependent on useServerPrepStmt connection parameter it would create either MySQLPreparedStatement or MySQLServerSidePreparedStatement
I am by no means a big fan of everything object-oriented or of design patterns , however in this case the alternative to server-side specific implementation class seems to be a lots of "if" statements mixed into in existing MySQLPreparedStatement methods .Given that PreparedStatement itself is a rather large interface, I'm afraid that code will go spaghetti way rather easily.
I will discuss with my mentors this week and take the necessary steps.Will continue posting about the steps taken.
Regards
Puneet.
On Sun, Jun 8, 2014 at 2:04 AM, Vladislav Vaintroub <wlad@montyprogram.com> wrote:
> -----Original Message----- > From: Puneet Dewan [mailto:puneetd30@gmail.com] > Sent: Samstag, 7. Juni 2014 03:58 > To: Vladislav Vaintroub > Cc: maria-developers@lists.launchpad.net > Subject: Re: [Maria-developers] Java Connector Coding till 5th June > > Hi Vladislav, > > > Honestly, initially I had thought of using > MySqlServerSidePreparedstatement. > But after discussion with Georg, I understood it was an overhead.
This is why I asked. I'm wondering what was the overhead exactly? And what is the plan to avoid the overhead? Is it to squeeze second implementation of java.sql.PreparedStatement interface into an already existing class?
> Even when discussed during code review with Massimo we decided to add > the useserverprepstmts feature using MySqlPreparedStatement and not to > use MySqlServerSidePreparedstatement. > Because this class just had a prepare and close and not a clear idea why this > class was created and almost all methods are empty.
This is easy to explan and can also be easily found with bzr, or Launchpad. The file was added in revision 424 http://bazaar.launchpad.net/~maria-captains/mariadb-java- client/trunk/revision/424 .. The comment says
"CONJ21- allow ResultSetMetaData to be retrieved from preparedStatement, before statement is executed.
Fix is using server-side prepared statement functionality - prepare command will return result set metadata among other information. Introduce MySQLServerSidePreparedStatement class, which in the future will be able to provide full-featured PreparedStatement functionality, using server side prepared statements internally."
This is the fix for the bug https://mariadb.atlassian.net/browse/CONJ-21 , to allow users to retrieve ResultSetMetadata priorto /without the execution of statement. This is only possible with server-side "prepare", no other way around it The class was meant to be expanded in the future, as the comment said.
> We are not removing client side prepared statement feature, both client and > server side prepared statement are there and will be used as per the > needs.I am just trying to add a useserverprepstmts feature > usingMySqlPreparedStatement and will be activated from the jdbc url i.e > jdbc:mysql://localhost:3306/test?useServerPrepStmts=true. > > If useServerPrepStmts is not used client side prepared statements will be > used.
Right, this makes sense.
> > Regards > > Puneet. > > > > > On Sat, Jun 7, 2014 at 3:02 PM, Vladislav Vaintroub > <wlad@montyprogram.com> wrote: > > > > > > -----Original Message----- > > From: Maria-developers [mailto:maria-developers- > > bounces+wlad=montyprogram.com@lists.launchpad.net] On > Behalf Of > > Puneet Dewan > > Sent: Donnerstag, 5. Juni 2014 07:43 > > To: maria-developers@lists.launchpad.net > > Subject: [Maria-developers] Java Connector Coding till 5th June > > Hi Puneet, > > > > 7.Then I saw that there is a class > MySqlServerSidePreparedStatement.java, > > > > Initially I coded the prepareStatement() ,close(),and execute() in > that class > > seperately. > > > > But after (Code review) discussion with Massimo, we donot need > to use that > > class. > > > I'm curious. What were the arguments for not using this class? That > class MySqlServerSidePreparedStatement.java was created for exactly the > purpose of implementing server-side prepared statements (user could > choose implementation based on parameter, e.g userServerPrepStmts like in > Connector/J). > > If the idea is that people do not need client-side prepared > statements, and server-side the only correct way to go, this is, based on my > experience, incorrect. Often, people would want parametrized statements > without the overhead of P_S (prepare, execute, close). > > > > Instead use MySqlPreparedStatement.java to do the same work.So > made > > changes accordingly. > > >