
ivan

ivan.revelli@synaptica.info

25 February 2010
L’inversione di tendenza ? ma speriamo di no, che l’Open Source abbia permesso a milioni di società e di individui singoli di poter accedere ,e dare il proprio contributo ,a Software prima inarrivabili è ormai noto. Era normale aspettarsi che tutti coloro che giustamente vivono sulle licenze dei “loro” software non vedano di buon occhio questa nuova filosofia, che a detta di molti non è una cosa che va contro le regole del mercato.
In questo senso non mi esprimo, ma credo che fino ad oggi la bilancia dei vantaggi e svantaggi di questa nuova filosofia di cooperazione penda fortemente dalla parte dei vantaggi.
Ulitmamente mi capita di leggere cose che mi lasciano un po sconcertato, una di queste fù l’articolo pubblicato da Riccardo che ad una riunione presso un grosso cliente sentì dire la frase “l’open source è illegale”.
Oggi leggendo ,come di mio consueto, il blog http://www.ossblog.it , che è un blog a mio avviso molto “fico” e attendibile mi ritrovo quest’articolo : “Usate software FOSS? Allora siete dei pirati!“.
C’era da aspettarselo? boh non credo comunque sia non sta a me decidere, penso che in tutte le cose ci voglia moderazione e in questo caso son andati un po oltre, creando anche una lista nera di paesi additati per questo.
a presto
ivan

ivan

ivan.revelli@synaptica.info

19 February 2010
by using some simple view in Oracle you can extract a lot of information about your DB schema, some explicit samples :
(assuming that MyDBOwner is the owner of the DB and ACTIVITY is a table of a schema, this sample is succesfully tested on Oracle 10g)
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– LIST OF USERS
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SELECT OWNER,COUNT(DISTINCT TABLE_NAME) FROM ALL_TAB_COLUMNS GROUP BY OWNER
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– LIST OF TABLES PER OWNER
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SELECT table_name FROM ALL_TAB_COLUMNS WHERE owner = ‘MyDBOwner’ GROUP BY table_name
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– LIST OF FIELDS PER TABLE
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SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH, NULLABLE, CHAR_LENGTH FROM ALL_TAB_COLUMNS WHERE owner = ‘MyDBOwner’ AND TABLE_NAME = ‘ACTIVITY’
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– FINDING PRIMARY KEYS
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SELECT COLUMN_NAME, DATA_TYPE, DATA_LENGTH, NULLABLE, CHAR_LENGTH FROM ALL_TAB_COLUMNS WHERE owner = ‘MyDBOwner’ AND TABLE_NAME = ‘ACTIVITY’
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– A single character that indicates the type of constraint: ‘C’ = NOT NULL, ‘P’ = PRIMARY KEY, ‘U’ = UNIQUE, and ‘R’ = FOREIGN KEY.
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SELECT UC.CONSTRAINT_NAME, UCC.* FROM USER_CONSTRAINTS UC, USER_CONS_COLUMNS UCC WHERE UC.OWNER=‘MyDBOwner’ AND UC.TABLE_NAME = ‘ACTIVITY’ AND UC.CONSTRAINT_TYPE = ‘P’ AND UC.CONSTRAINT_NAME = UCC.CONSTRAINT_NAME
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a great article about this is : http://college.yukondude.com/2002_09_comp210/html/note-container.php?file=10^Handout^Oracle_Metadata and on wiki too at this address http://en.wikipedia.org/wiki/Oracle_metadata#Example_2:_finding_columns
bye ivan

ivan

ivan.revelli@synaptica.info

17 February 2010
(This article is a draft but if something is of interesting …. )
The fantastic world of old Midas now called DataSnap introduced the TClientDataSet component , that is a in memory DataSet for Delphi and C++ Builder. With TClientDataSet was introduced the concept of Brief Case model Application Style.
A brief case model App. is the best concept application that exchnage data between server when and where there is a connection. Now TClientDataSet have two type of rapresenting the in memory data, one binary and one in a static xml format that is well explained in this article on Embarcadero site : http://edn.embarcadero.com/article/10405.
Using Java , the world of JDBC and ,of course, Tomcat we are trying to provide data to a client dataset via some Servlet and update data parsing the Delta sended by our TclientDataSet. So that we can connect to Oracle for example without usinig direct connection or driver.
We also found a similar project done with pHp posted on the Zend site at this url : http://www.zend.com//code/codex.php?ozid=1049&single=1.
Soon we will post all about that.
stay tuned
bye ivan

ivan

ivan.revelli@synaptica.info

15 February 2010

Delphi was born exactly fifteen years ago from Today, Marco Cantu on his web site have posted a great article on this because he is one of the first guru of this beatifull dev language… the article

ivan

ivan.revelli@synaptica.info

11 February 2010
this article is a draft, but i published it because if you need something of that the resources that i found on internet are very interesting.
mission of the post : mixing dynaic query and functions to allow join from db2db
Dynamic SQL Great Article : http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/dynamic.htm#CHDGJEGD
Dreate functions and consuming inside SQL , a greate article at http://articles.techrepublic.com.com/5100-10878_11-5259821.html

ivan

ivan.revelli@synaptica.info

11 February 2010

Today the second version of ZK Calendar is ready ( official article on : http://www.zkoss.org/product/zkcalendar.dsp) . Tring the demo version at http://zcal.zkoss.org/ the first impression is that this new version is faster then the older one. I don’t know why is only a sansation. But in conclusion for me is one of the best planning component that i saw until now.