Thank you very much.
And what is the equivalent please for:
SUM FIELD->TOTAL TO nt
Thanks.
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Board index FiveWin for Harbour/xHarbour TDataRow and ADO questions
Elvira,
You can just iterate through the records adding the field values. Or, better, you can use a query like this:
and later:
EMG
elvira wrote:Thank you very much.
And what is the equivalent please for:
SUM FIELD->TOTAL TO nt
Thanks.
You can just iterate through the records adding the field values. Or, better, you can use a query like this:
SELECT SUM( Total ) AS nt FROM MyTable WHERE MyConditionand later:
? oRs:Fields( "nt" ):ValueEMG
Thank you Enrico.
One little question more, as now we don´t have to do PACK o Reindex, is there any command via SQL sentence to issue from time to time to optimize the database?:
Kind regards 
Elvira:
If you speak Spanish let me know your email address.
Regards
SOI, s.a. de c.v.
estbucarm@gmail.com
http://www.soisa.mex.tl/
http://sqlcmd.blogspot.com/
Tel. (722) 174 44 45
Carpe diem quam minimum credula postero
estbucarm@gmail.com
http://www.soisa.mex.tl/
http://sqlcmd.blogspot.com/
Tel. (722) 174 44 45
Carpe diem quam minimum credula postero
Elvira,
Yes, but only for MDB database:
EMG
elvira wrote:Thank you Enrico.
One little question more, as now we don´t have to do PACK o Reindex, is there any command via SQL sentence to issue from time to time to optimize the database?:
Kind regards
Yes, but only for MDB database:
LOCAL cCn1 := "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=MyDatabase.mdb"
LOCAL cCn2 := "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=MyCompactedDatabase.mdb"
LOCAL oJro
oJro = CREATEOBJECT( "JRO.JetEngine" )
oJro:CompactDatabase( cCn1, cCn2 )EMG
Hi Mr. Rao,
Is xBrowse works with array of TDataRow?
Thanks
Regards,
Hakan ONEMLI
Harbour & MSVC 2022 & FWH 23.06
Hakan ONEMLI
Harbour & MSVC 2022 & FWH 23.06
Mr. Enrico,
Thank you a lot.
Appart from w3schools, is there a book preferent to learn ADO?. For example, the compact of database is not explanied at that site.
Also, Microsoft.Jet.OLEDB.4 works in Windows 8?.
Thanks. Kind regards
Elvira,
We are here to help and serve.
Because it's not related with ADO. It's another class hierarchy (JRO).
I don't know for sure but it should work.
EMG
elvira wrote:Mr. Enrico,
Thank you a lot.
We are here to help and serve.
elvira wrote:Appart from w3schools, is there a book preferent to learn ADO?. For example, the compact of database is not explanied at that site.
Because it's not related with ADO. It's another class hierarchy (JRO).
elvira wrote:Also, Microsoft.Jet.OLEDB.4 works in Windows 8?.
I don't know for sure but it should work.
EMG
Hello,
very very interesting and useful topic , as we are wainting TDatarow to be fixed and start using ADO too.
I was wondering if ADO works with FWH64 bits, for SQL, MySQL and Access.
Best regards,
Also, Microsoft.Jet.OLEDB.4 works in Windows 8?.
Yes it works.
And it is also time to start using latest ACE.OLEDB drirvers instead of Jet.
Is xBrowse works with array of TDataRow?
It is just the opposite of the intention with which TDataRow class is created.
The intention is to collect the field (column) information of a single row of a table ( of any datasource ) for modification/adding and then saving the information. The process of reading and saving is transparent the application program, so that the same code can be used for all kinds of datasources.
Still to answer your question, Yes we can create an xbrowse with an array of TDataRow objects, but that is of no special advantage.
Regards
G. N. Rao.
Hyderabad, India
G. N. Rao.
Hyderabad, India
Hello,
When the table is empty in ADO, operations such as oRs:AbsolutePosition block the program instead of giving an error.
Other commands, such as oRs:Movefirst() do produce an error.log.
In DBF for example in a database with no records, you could issue dbgotop() or dbgobottom() with no problems, but oRs:Movefirst() fails.
Is there a way in ADO that they don´t produce such behaviour and work as DBF in an empty table?.
Thanks!
Elvira,
No, you have to check for the !empty table first or trap the error.
EMG
elvira wrote:Hello,
When the table is empty in ADO, operations such as oRs:AbsolutePosition block the program instead of giving an error.
Other commands, such as oRs:Movefirst() do produce an error.log.
In DBF for example in a database with no records, you could issue dbgotop() or dbgobottom() with no problems, but oRs:Movefirst() fails.
Is there a way in ADO that they don´t produce such behaviour and work as DBF in an empty table?.
Thanks!
No, you have to check for the !empty table first or trap the error.
EMG
Enrico, thank you.
So I have to use many try/catch, but won´t be too slow for the application performance?.
Thankls
Elvira,
No, you don't have to. You can just open the table and test for !oRs:EOF. Then go on with the rest of the code if the table is not empty.
EMG
elvira wrote:Enrico, thank you.
So I have to use many try/catch, but won´t be too slow for the application performance?.
Thankls
No, you don't have to. You can just open the table and test for !oRs:EOF. Then go on with the rest of the code if the table is not empty.
EMG
Elvira
Enrico has given you some GREAT advice!! .. I started with ADO many years ago with his help.
A couple of ADO 'gotchas' you need to know ..
1) When working with SQL databases, you have to be aware of NULL fields. When you Add or Edit a Sql row, it is best to apply a VALUE to each field even if it is " " or ctod(""). Unlike .Dbf .. if you do not apply a value to a field, SQL assigns it 'NULL' and if you try to manipulate that field without realizing it was NULL, your program will fail at run-time.
2) Also .. if you are using xHarbour .. there is a new dataType "T" for Date\Time and if you assign a DateTime value to a variable or try to manipulate that value like valtype "D" you will run into all kinds of problems.
Many of our ADO friends use a function like this to convert Valtype "T" back to Valtype "D"
and when you assign a DateTime value to a variable I would suggest this
Rick Lipkin
Enrico has given you some GREAT advice!! .. I started with ADO many years ago with his help.
A couple of ADO 'gotchas' you need to know ..
1) When working with SQL databases, you have to be aware of NULL fields. When you Add or Edit a Sql row, it is best to apply a VALUE to each field even if it is " " or ctod(""). Unlike .Dbf .. if you do not apply a value to a field, SQL assigns it 'NULL' and if you try to manipulate that field without realizing it was NULL, your program will fail at run-time.
2) Also .. if you are using xHarbour .. there is a new dataType "T" for Date\Time and if you assign a DateTime value to a variable or try to manipulate that value like valtype "D" you will run into all kinds of problems.
Many of our ADO friends use a function like this to convert Valtype "T" back to Valtype "D"
//--------------------------
Function TtoDate( tDate )
If empty( tDate)
  Return( ctod("00/00/00"))
Endif
If ValType( tDate ) = "D"
  Return(tDate )
Endif
Return( stod( substr( ttos( tDate ), 1, 8 ) ))and when you assign a DateTime value to a variable I would suggest this
dDob      := If( empty(oRsPet:Fields("Dob"):Value), ctod("00/00/00"),;
            TtoDate(oRsPet:Fields("Dob"):Value))Rick Lipkin