ADORDD FAQs
Posted: Sun Nov 15, 2015 6:26 pm
After several users and client questions I decided to compile them all in adordd faqs.
Hope it will help you deciding to port your app to SQL.
1) Is adordd pure ADO ?
Yes
2) Does it work like another rdd without any limitations ?
Yes and its even more compatible with clipper dbf kind of rdds than ADS rdd.
You don't need anymore to be stuck to dbf kind of rdds.
3) Can I just link it with my app and run?
No.
You need to pre configure adordd with a couple of SETs in the top of your app prg,
but you don't need to alter any of your app code.
Please check 01_README.PDF and tryadordd.prg at github.
All this will take only a couple of minutes.
4) How do I configue adordd ?
At your initial or main procedure place:
5) Does it works with xHarbour and Harbour ?
Yes.
6) How do I port my dbfs to SQL and how long can it take?
Place in your initial procedure after all adordd SETs:
Choosing the last parameter .f. lOverwrite it allows you if you need to interrupt
porting of dbfs to SQL to run it again from the last uploaded table.
After loading it your app will continue execution now in the SQL chosen engine.
You can after comment that line to avoid run it again when app starts again.
Depending n your tables average size (millions of records) it can take long time.
If this is your case leave it uploading during night.
7) Can I open tables with million of records without a where clause?
Yes.
In this case you might use SET ADO THRESHOLD to wait a little more in app start up but
it will be extremely fast during execution.
When I open big tables several times during app execution doesn't this lead to
out of memory or very slow opening of that table?
Adordd builds each table recordset only once.
If your table recordsets have million of records you will need enough memory for it and it can easily
reach some hundred MB or more.
When you open that table again the memory consumption its minimum as adordd clones that table set, which
means a kind of pointer to previous open recordset being extremely fast opening it again and very
low on memory use.
9) Can I use other SQL classes or function like adofuncs with adordd ?
Yes.
You can use the traditional navigational approach like clipper or SQL approach with INSERT, UPDATE, etc or a mix of both.
Adordd will have always the table recordset updated with table last version no matter if for ex updates are made
through functions or SQL statments through adordd or any other classes or functions.
10) But aren't there any restrictions using adordd and don't I need have to change any of my app code?
No restrictions.
No app change code.It works like any other dbf kind of rdd.
11) Is it fast like my dbf rdd application?
Its not so fast as dbf kind of rdd if your app has only 1 to 5 users but almost as fast.
The point is that adordd will not have performance degradation if your app works with 5 or 300 users
and neither on LAN or WAN as opposite to dbf rdd.
Adordd will need minimum working load on your SQL engine server.
12) Does it has transaction control ?
It has everything your SQL engine might offer.
If your chosen SQl engine is Transactional you will have transactions control in adordd.
13) What SQL engines can I use ?
ADS
ACCESS
ANYWHERE
DBASE
POSTGRE
FIREBIRD
FOXPRO
INFORMIX
MSSQL
MYSQL
ORACLE
POSTGRE
SQLITE
But others can be easily added to be supported.
14) What about if MS stops development or support to MS ADO in future?
Adordd its prepared to work with any other user class that provides the few methods and data
adordd uses from MS ADO.
This class could use arrays or dbfs as recordsets and interface through C to each SQL library bypassing
ODBC which might be much faster.
Hope it will help you deciding to port your app to SQL.
1) Is adordd pure ADO ?
Yes
2) Does it work like another rdd without any limitations ?
Yes and its even more compatible with clipper dbf kind of rdds than ADS rdd.
You don't need anymore to be stuck to dbf kind of rdds.
3) Can I just link it with my app and run?
No.
You need to pre configure adordd with a couple of SETs in the top of your app prg,
but you don't need to alter any of your app code.
Please check 01_README.PDF and tryadordd.prg at github.
All this will take only a couple of minutes.
4) How do I configue adordd ?
At your initial or main procedure place:
Code: Select all
#INCLUDE "adordd.ch"
RddRegister("ADORDD",1)
RddSetDefault("ADORDD")
IF RDDSETDEFAULT() == "ADORDD"
//clipper index expressions as used by your app.
//if your app uses dynamic build tables names place here a tablename only the static part of it.
SET ADODBF TABLES INDEX LIST TO check 01_readme.pdf for arrray spec
//temporary index names static part of index name
SET ADO TEMPORAY NAMES INDEX LIST TO {"TMP","TEMP"}
//you should place here all index expressions that change the type or en of a field and or your UDFs
SET ADO INDEX UDFS TO {"IF","&","SUBSTR","==","DESCEND","MYFUNC"}
//only needed for engines not supporting these kind of fields ex oracle sqlite access
SET ADO TABLES LOGICAL FIELDS LIST TO { { "ACESS", { "PODEFAZER" } } }
//only needed for engines not supporting exact decimal field notation ex access sqlite
SET ADO TABLES DECIMAL FIELDS LIST TO ;
{ {"ENCCLIST",{"PRECOVENDA",4,"PRECOVEEST",4 } },;
{"ENCFOCLI", {"PRECOUNIT", 4 } } }
Both these sets are written for you by adordd when uploading the tables.
//defaut field to be used as recno
SET ADO DEFAULT RECNO FIELD TO "HBRECNO"
//only needed if diferent for tables with different recno field from the default
//SET ADO FIELDRECNO TABLES LIST TO {{"TABLE1",{"ID"}},{"TABLE1",{"ID"}}}
//field to be used as deleted flag
SET ADO DEFAULT DELETED FIELD TO "HBDELETE"
//only needed if diferent for tables with different deleted flag field from the default
//SET ADO FIELDDELETED TABLES LIST TO {"CLIENTE","HBMYDLETED1" }
// if you want to have lock control as in any other rdd.
// you will need to have a share path to it
// working in WAN you will need for ex a VPN to this share path.
//SET ADO LOCK CONTROL SHAREPATH TO "d:\followup-testes" RDD TO "DBFCDX"
SET ADO FORCE LOCK OFF
// here connection gets active
SET ADO DEFAULT DATABASE TO
//upload the database path structure as part of the table name.
//suppose that you have same table name in different folders.
// without tis set you could not upload both.
// with thsi set the path becomes part of the table name.
SET ADO TABLENAME WITH PATH ON
// uploaded with one path working now with another
SET ADO ROOT PATH TO .... INSTEAD OF .....
//this set has an impact on performance as app execution continues
//before recordset itsstill being build.
SET ADO CACHESIZE TO 50 ASYNC ON ASYNCNOWAIT ON
//pre open recordset at startup for faster acces during app execution
SET ADO PRE OPEN THRESHOLD TO 5000
ENDIF
Yes.
6) How do I port my dbfs to SQL and how long can it take?
Place in your initial procedure after all adordd SETs:
Code: Select all
hb_AdoUpload( "C:\My root databse path", "DBFCDX", "MY SQL CHOSEN ENGINE", .f. )
porting of dbfs to SQL to run it again from the last uploaded table.
After loading it your app will continue execution now in the SQL chosen engine.
You can after comment that line to avoid run it again when app starts again.
Depending n your tables average size (millions of records) it can take long time.
If this is your case leave it uploading during night.
7) Can I open tables with million of records without a where clause?
Yes.
In this case you might use SET ADO THRESHOLD to wait a little more in app start up but
it will be extremely fast during execution.
When I open big tables several times during app execution doesn't this lead toout of memory or very slow opening of that table?
Adordd builds each table recordset only once.
If your table recordsets have million of records you will need enough memory for it and it can easily
reach some hundred MB or more.
When you open that table again the memory consumption its minimum as adordd clones that table set, which
means a kind of pointer to previous open recordset being extremely fast opening it again and very
low on memory use.
9) Can I use other SQL classes or function like adofuncs with adordd ?
Yes.
You can use the traditional navigational approach like clipper or SQL approach with INSERT, UPDATE, etc or a mix of both.
Adordd will have always the table recordset updated with table last version no matter if for ex updates are made
through functions or SQL statments through adordd or any other classes or functions.
10) But aren't there any restrictions using adordd and don't I need have to change any of my app code?
No restrictions.
No app change code.It works like any other dbf kind of rdd.
11) Is it fast like my dbf rdd application?
Its not so fast as dbf kind of rdd if your app has only 1 to 5 users but almost as fast.
The point is that adordd will not have performance degradation if your app works with 5 or 300 users
and neither on LAN or WAN as opposite to dbf rdd.
Adordd will need minimum working load on your SQL engine server.
12) Does it has transaction control ?
It has everything your SQL engine might offer.
If your chosen SQl engine is Transactional you will have transactions control in adordd.
13) What SQL engines can I use ?
ADS
ACCESS
ANYWHERE
DBASE
POSTGRE
FIREBIRD
FOXPRO
INFORMIX
MSSQL
MYSQL
ORACLE
POSTGRE
SQLITE
But others can be easily added to be supported.
14) What about if MS stops development or support to MS ADO in future?
Adordd its prepared to work with any other user class that provides the few methods and data
adordd uses from MS ADO.
This class could use arrays or dbfs as recordsets and interface through C to each SQL library bypassing
ODBC which might be much faster.