MARIADB ROWSET BATCH DML OPERATION EXAMPLE

[shrifw]

Dear Rao Sir,

May I request to share the example of Maria DB Rowset Batch Operation in which record add / Modify / Delete and finally save the data in batch mode. Thanks in advance..!


Thanks
Shridhar

[nageswaragunupudi]

Will you please try this?

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oRs := oCn:RowSet( cSql )
oRs:SetBatchMode( .t. )
XBROWSER oRs FASTEDIT
if oRs:IsBatchEdited()
   if MsgYesNo( "Save Changes?" )
      oRs:SaveBatch()
   else
      oRs:CancelBatch()
   endif
endif
XBROWSER oRs
 

It is very important that the Primary Key(s) should be included in the rowset.

[shrifw]

Dear Rao Sir ,

Will try and update you. Many thanks...!!

Thanks
Shridhar

[vilian]

Mr Rao,

What is the differenc between BATCH and TRANSACTION ? Could you explain it to me ?

[nageswaragunupudi]

TRANSACTION:
We use this feature when we need to update/insert more than one table and want that either all changes to be written or none.
In other words, we do not want a situation where some tables are updated and some or not due to whatever reasons.

For example we want all these updates to be written

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aSql := { "UPDATE table1 ... WHERE ... ", ;
          "UPDATE table2 ... WHERE ... ", ;
          ..more.., ;
        }
if WriteAllOrNone( oCn, aSql )
   ? "Written"
else
   ? "fail"
endif
//-------------------------------
function WriteAllOrNone( oCn, aSql )

local cUpdateSql

oCn:BeginTransaction()
for each cUpdateSql IN aSql
   oCn:Execute( cSql )
   if oCn:nError != 0
      oCn:RollBack()
      return .f.
   endif
next
oCn:CommmitTransaction()   

return .t.
 

BATCH:
Same way as in ADO, we can also use RowSet in BatchMode.

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oRs := oCn:RowSet( cSql )
oRs:SetBatchMode( .t. )
 

In this case all changes (add/modify/delete) we make to the RowSet (or RecordSet in ADO) are all made to the RowSet/RecordSet in memory, but not written to the database.
After making all required changes, the we can decide to write all changes to the physical database or discard all changes.

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oCn:SaveBatch()  // write all changes
oCn:CancelBatch() // discard all changes
 

This is mostly useful in Master/Child edits like Invoices, Quotations, Vouchers, etc.

[vilian]

Thank you

[shrifw]

Dear Rao Sir ,

As requested , could you please provide code to use extended the feature of XBROWSE , DATAROW & ROWSET.

Thanks
Shridhar

[vilian]

Do you know if is possible to use Transaction with BEGIN SEQUENC/RECOVER? Something like this:

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BEGIN SEQUENC
      oCn:BeginTransaction()
         oCn:Insert(...)
         oCn:Insert(...)
         oCn:Insert(...)
     oCn:CommitTransaction()

RECOVER USING oError
      oCn:RollBack()
END SEQUENC
 

oCn:CommitTransaction() only will be executed it there is no any fail during oCn:Insert().