PLSQL corner

PLSQL loop inexed by letters

But this is not portable across character sets. I think a better solution is to declare up front your index variables like this:

That way if you change character sets (e.g. to utf8) you are not reliant on a collating sequence that doesn’t match your char set.

RegEx never endig story….

It is example of use RegEx to prepare SQL data for SELECT/UPDATE operation. /^.*/gm ^ asserts position at start of a line .* matches any character (except for line terminators) * Quantifier — Matches between zero and unlimited times, as many times as possible, giving back as needed (greedy) Global pattern flags g modifier: global. Read more about RegEx never endig story….[…]

SQL corner: 7 kind of SQL Joins. Including : INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN

Infographic of the 7 kind of SQL Joins. Including : INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, with or without the intersect. Very useful for web developer. Source : http://sql.sh #SQL #JOIN     Source: Pinterest http://sql.sh/2401-sql-join-infographie Other sources https://docs.oracle.com/cd/B28359_01/server.111/b28286/queries006.htm https://www.techonthenet.com/oracle/joins.php – also include examples and old Oracle notations

Unique session ID

The UNIQUE_SESSION_ID function returns a character string unique to the session among all sessions currently connected to the database. The return string can be up to 24 bytes in length. Multiple calls to the function from the same session will always return the same string. The program header follows:

Notes UNIQUE_SESSION_ID is functionally identical Read more about Unique session ID[…]

Narzędzia to projektowania baz danych

GNU-GPL OpenSystemArchitect http://www.codebydesign.com/ Power*Architect http://code.google.com/p/power-architect/ Druid http://druid.sourceforge.net/ ERW http://erw.dsi.unimi.it/ Dia http://live.gnome.org/Dia XML to DDL (python scripts) http://xml2ddl.berlios.de/ Graphiz – I believe I’ve read of people using it to reverse engineer from DDL http://graphviz.org/ Multiple versions/licenses (each has a “free” and a “not-free” version) DBVisualizer Toad http://www.toadsoft.com/ Not-free Microsoft Visio – (If you already have it, Read more about Narzędzia to projektowania baz danych[…]

Oracle PL/SQL: Bulk Processing with BULK COLLECT and FORALL

Bulk Processing with BULK COLLECT and FORALL· BULK COLLECT: SELECT statements that retrieve multiple rows with a single fetch, improving the speed of data retrieval· FORALL: INSERTs, UPDATEs, and DELETEs that use collections to change multiple rows of data very quicklyPL/SQL is so tightly integrated with the SQL language, you might be wondering why special Read more about Oracle PL/SQL: Bulk Processing with BULK COLLECT and FORALL[…]

Pomiar wydajności bazy danych

Przy wyborze hostingu warto sprawdzić jak prezentuje się wydajność zakupionych serwerów może w tym pomóc skrypt http://www.linux.pl Po przeróbkach skryptu zainstalowałem go na serwerze http://ultimasolution.pl/projects/bechmark_phpmysql/?iterations=50000&tabletype=MYISAM i oto co wyszło: Testing a(n) MYISAM table using 50000 rows. Successfully created database speedtestdb Sucessfully created table speedtesttable This MySQL instance does NOT support MYISAM tables Table Type Verified: Read more about Pomiar wydajności bazy danych[…]