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Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Fri Sep 17, 2021 6:49 pm
by nageswaragunupudi
After seeing this post, I am considering introducing two switches:
DATA lRaiseErrorDML INIT .f.
DATA lRaiseErrorALL INIT .f.
I can change the name of the variables to lThrowError, etc. if you all suggest
If programmer sets :lRaiseErrorDML := .t., then the Execute() method will raise a runtime error for failure of DML statements only ( DML: INSERT/UPDATE/DELETE ) and will be silent for errors with other SQL queries.
If programmer sets :lRaiseErrorALL := .t., then the Execute() method will raise a runtime error for failure in execution of any query.
Then we can write:
Code: Select all | Expand
oCn:BeginTransaction()
oCn:lRaseErrorDML := .t.
TRY
oCn:Insert(...)
....
CATCH
lSaved := .f.
oCn:RollBack()
END
oCn:lRaiseErrorDML := .f.
if lSaved
oCn:CommitTransaction()
endif
Welcome any suggestions, before I finish the changes
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 4:17 am
by carlos vargas
DATA lRaiseErrorDML INIT .f.
DATA lRaiseErrorALL INIT .f.
Ok rao.
But, transaction in mysql is only for insert, update and delete statements?
Umm. Alter table.., etc. Is not supported in transaction?
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 10:44 am
by Ariel
Mr. Rao,
A mi modesto parecer deberia funcionar como el :execute()
TRY
oServer:Begintrasaction()
oServer:Execute( "INSERT INTO ... ")
oServer:Execute( "INSERT INTO ... ")
oServer:Execute( "INSERT INTO ... ")
oServer:Execute( "INSERT INTO ... ")
CATCH oErr
oServer:RollBack()
FINALLY
oServer:CommitTransaction()
END
De esta forma SI funciona el break automaticamente por el error.
Saludos.
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 10:51 am
by nageswaragunupudi
But, transaction in mysql is only for insert, update and delete statements?
Yes.
Only for DML statements, i.e., INSERT, UPDATE and DELETE statements
Umm. Alter table.., etc. Is not supported in transaction?
Yes. Not supported.
One more important point to remember is that if at all we use any DDL statement inside a transaction, the transaction gets committed and then this DDL statement is executed. So we need to be careful not to use any statements not compatible inside a transaction.
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 11:05 am
by Ariel
Mr. Rao,
a mi modesto entender deberia funcionar como cuando usamos :Execute()
TRY
::oServer:BeginTransaction()
::oServer:Execute( "INSERT INTO ... ")
::oServer:Execute( "INSERT INTO ... ")
::oServer:Execute( "INSERT INTO ... ")
::oServer:Execute( "INSERT INTO ... ")
::oServer:Execute( "INSERT INTO ... ")
CATCH oErr
::oServer:RollBack()
FINALLY
::oServer:CommitTransaction()
END
De esta manera salta solo por el catch
Saludos.
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 3:00 pm
by carlos vargas
from help of xharbour
FINALLY
The finally section is guaranteed to be executed, no matter if an error was handled or not.
in you example
The commit would be executed even when there is an error?
Anyway, I don't know if harbor supports that instruction.
salu2
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 3:10 pm
by nageswaragunupudi
Anyway, I don't know if harbor supports that instruction.
Harbour does not support "TRY/CATCH" syntax at all. It supports BEGIN SEQUENCE/END SEQUENCE only.
xHarbour supports both.
fivewin.ch translates TRY/CATCH to BEGIN/END SEQUENCE for Harbour users. FINALLY also is translated.
Your observation about FINALLY is right.
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 3:11 pm
by carlos vargas
yes, work with xhb.hbc
Code: Select all | Expand
// The example demonstrates program flow for a TRY..CATCH sequence
#ifdef __HARBOUR__ //from fivewin.ch
#ifndef __XHARBOUR__
#xcommand TRY => BEGIN SEQUENCE WITH {| oErr | Break( oErr ) }
#xcommand CATCH [<!oErr!>] => RECOVER [USING <oErr>] <-oErr->
#xcommand FINALLY => ALWAYS
#xtranslate Throw( <oErr> ) => ( Eval( ErrorBlock(), <oErr> ), Break( <oErr> ) )
#endif
#endif
PROCEDURE Main()
LOCAL oErr
TRY
? "Trying"
oErr := ErrorNew()
oErr:Args := { date(), time(), pi() }
oErr:CanDefault := FALSE
oErr:CanRetry := FALSE
oErr:CanSubstitute := FALSE
oErr:GenCode := EG_SYNTAX
oErr:Severity := ES_ERROR
oErr:SubSystem := "MYTEST"
oErr:SubCode := 1001
oErr:Operation := "Prueba de error"
oErr:Description := "Descripcion de la prueba de error"
Throw( oErr )
CATCH oErr
? "Caught:", oErr:SubCode, oErr:Operation, oErr:Description
? "Throwing to outer, should be deferred"
//Throw( oErr )
FINALLY
? "Finalized"
END
? "Oops, should have Re-Thrown, after the FINALLY."
RETURN
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 3:58 pm
by nageswaragunupudi
Hace años que uso tmysql con estos cambios, y me ha funcionado bien, me gusta mucho la implementación de mysql en fwh pero veo que tengo que hacer muchos cambios
FWH Insert method supports your Insert2 method syntax also.
oCn:Insert( cTable, { { "fld1", "val1" }, ... { "fldN", "valN" } } )
also works.
Soon we are going to implement lThrowError like functionality.
May I know what do you advise to make migration easlier?
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sat Sep 18, 2021 5:10 pm
by carlos vargas
The only thing about transactions, the other thing is easy, someone else?
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sun Sep 19, 2021 10:22 am
by nageswaragunupudi
Will be available in the next release.
Applies to execution of DML statements "INSERT,UPDATE,REPLACE,DELETE" directly using oCn:Execute() and to methods:
method Insert(...)
method Upsert(...)
method Update()
Implemented new
DATA lThrowError AS LOGICAL INIT .f.
Recommended usage:
Code: Select all | Expand
local lError := .f.
oCn:BeginTransaction()
oCn:lThrowError := .t.
TRY
oCn:Insert(....)
oCn:Update(...)
oCn:Execute( "INSERT ... " )
...
CATCH
lError := .t.
END
oCn:lThrowError := .f.
if lError
oCn:RollBack()
else
oCn:CommitTransaction()
endif
Re: MySql Nativa Transacciones. At. Mr. Rao
Posted: Sun Sep 26, 2021 2:08 pm
by Marcelo Roggeri
Mr Rao, buenísimo muchas gracias es bueno saberlo
Funciona de las dos maneras.
Solo utilizo Harbour
Saludos