XProfan

English

Jörg
Sellmeyer

course 3: SQL with XProfan - Content

- its but planned, it, in further versions fortzusetzen.

part 1: introduction introduction

- that one with the same command on The unterschiedlkichsten Databases grab can,

- One change the Datenbankherstellers or the Betriebssystemes

- ODBC is the Windowseigene interface To SQL-able Databases.

- wants I another data base using, muß I only whom driver exchange.

- (Dass the manufacturers the different Databases then still ex and on smaller ones Eigenheiten permit, The under Umständen To geringfügigen adjustments lead, in wonder but nevertheless not really somebody.)

- One far verbreitetes prejudice behauptet, that the circanambulation with SQL integral komplizierter is, as with dBase.

- an Hürde is sure The Initialisierrung of SQL,

- not tougher as with dBase-commandrn,

- (Hierbei is though hereon To respect, not by SQL on a gerfarewell with dBase opened scheduler access and inverse.)

- If one on Databases on others through one networking connected computer grab wants and/or with several Benutzern on dieselbe data base grab wants, comes one circa SQL not around.
uäh -
If one on Databases another, through one networking connected, computer grab wants, comes one circa SQL not around. This is too for drop, that several user on dieselbe data base grab.

- for this course want we first of all with dBase-Dateiern stay.
Easter naht...

- we're this entry You can and the Button "Konfigurieren" anwählen, see we, thereß with the option "Verzeichnis" one area "aktuelles directory nutzen" angekreuzt is. the means, thereß we over the names "dBASE-Files always on The dBase-tables in the actually directory grab can. (with dBase form any tables one Verzeichnisses a dataabank.)
rather: ... grab can, there with dBase any ...

- circa these Datenbank now too by SQL benefit to,

- (Later there were still a couple extensions, but moreover on another place More.)
here z.B. find I The clinging meaningfully. though missing the point...

- so grab we on The course-data base in the angegwevenen directory

- strain weir our Program circa a input the Namens the Datenquelle:

- as Parameter follow the commands the name the scheduler and thereafter, in clinging through Kommas separated, each boxes with their type.

- what passieret, we're the program one second time started,
the was now but no solid, or?

- we're now but integrally bewußt The scheduler new produce want,

- The korrekte Creation the scheduler can we with the Datenbankhelfer of XPropfan to check on.

- with the aide "Datenbankstruktur" can we over the exhaust scheduler/reading the structure the scheduler reading. Mit the aide "Tabellen bearbeiten" could we even data prompt, change and delete. (the goes naturally only tables in the dBase-stature.)

- two items muß the commands know:

- with VALUES muß with this Syntax for each area the scheduler one worth stand.

- The aide "Tabellen bearbeiten" shows, thereß the Datensatz in the scheduler "buecher.dbf" arrived is.

- then muß I the SQL-Bnefehl strain and indicate, which Split I fill would like:

- The Opportunities, Data from of/ one or several tables To detect and auszugeben, are almost unerschöpflich.

part 3: complex Search and Datumsfelder

- The Opportunities the SELECT-commandses in SQL.
here showm itself namely The strengthen of SQL to the dBase-Implementierung in XProfan.

- I have one small Progreamm written, thereß any discussed mutants demonstrating. i will it here row for row durchghwedlocks.
here only simple s!

- If I onem date prompt wants, thereß 5 days zurückliegt, could I z.B. write:
s.o.

- herewith läßt itself the Suchergebnis discretionary eingrenzen! The row has behind WHERE subesquent construction:

- Aggregatfunktionen are functions, The over any Entries of/ one slot gegehen (aggregate = total).

- the example determined To all Büchern a Preisaufschlag of 50%:

- In unserem example go first of all The last (rechten) 5 letters the Authorsen outputted
[...]

- thereby standing one "%" for as much as you want characters and a "_" (Unterstrich) for extnude one characters.

- the funktioniert not only with Zeichenketten, separate too with others Feldtypen:

- The Möglichen Results go behind the IN in clinging,

- SQL läßt itself sozusagen as Taschenrechner wenßneed. so the but at Syntaxcheck no Problems gives, muß nevertheless a scheduler indicated go.

- disturbing works only, thereß it so often outputted becomes:

- we're with the WHERE-circumstance The thing so retrenching, thereß only one Datensatz found becomes, see it rather from.

part 4: data staturetiert Show, process, change and delete

- To Beginn becomes The known Büchertabelle, How in the last Kursteep described, filled.

- 0 = Display in the Mainwindow the Programes

- @Set("SQLNull",...): statement one Field, the nothing einthält

- The spending in the Mainwindow bid itself in the integralen only for Testzwecke on,

- so the Anzeigeergebnis well on The Bildschirmseite paßt, had we yet always only a part the boxes displayed. we're with @Set("SQLColWidth",20) The maximum length one Field on 20 characters limit, then paßt it too for all boxes:

- For this, muß the second Parameter of @db("SQLExec" the value 1 having.

- If the number the Datensatzes in SatzNr% standing, läßt itself one beliebiger Datensatz with following row detect:

- The here beschriebene Solution läßt relatively simply one arbitrary works with the found Datenmenge To.

- copy the spending in Stringlisten or Stringggrids
ggg Gresslufthammer Gerhard

- naturally must we hereon respect, thereß itself these Separator from the Separator discern, that which The boxes within one Satzes part.

- For this, ewmpfiehlt itself the export the data in the CSV-stature.

- to put we our Separator means itst eggnmal the Semikolon one:
separated

- first of all the Importassistent on and it muß the Semikolon as Separator select go.

- we're meanwhile know, thereß the book of F.A. 7,90 Euro cost

- in the folgenden raise we The prices all books circa 20%:
[...]

- it go any Sätze unwiderruflich deleted, on The The circumstance zutrifft.

Windows XP SP2 XProfan X4
... und hier mal was ganz anderes als Profan ...