perl usage at database applications
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The document discusses various techniques for querying databases and generating reports from the query results using Perl. It provides examples of using DBI and SQL to query databases and format output, techniques for binding variables, preparing queries, and fetching and printing rows. Additional examples show merging and transforming tabular data for different output formats.
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perl usage at database applications
- 1. Perl DBI usage at report building Joe Jiang [email_address]
- 2. Perl Language Practical Extraction and ... Reporting Language
- 3. Perl Programmer Laziness Impatience Hubris (Boldness)
- 4. DBMS Database Management (descide) System
- 5. DBI.pm The gate to Management level programming
- 6. Back to reporting The man in breau The game they played The suggestion I once made on OLAP
- 7. Chemical Perl (Gas-ware) PHP for website Python for architecture Ruby for rails Perl for what?
- 8. Reports again DMBS is the container SQL is for query Perl is the formater
- 9. Give me Excel Copy HTML table into Excel Or, name HTML as .xls Use some IDE tool?
- 10. Toolset basic $ echo 'select SESSION_ID, HIT_ID from hit where USERNAME=? and ACCESS_TIME between to_date(?,?) and to_date(?,?)' > session.sql ↵
- 11. It worked $ bofc < session.sql user-123 201106122345 YYYYMMDDHH24MI 201106122357 YYYYMMDDHH24MI | wc -l ↵ SESSION_ID HIT_ID 12
- 12. And ... $ bofc < session.sql user-123 201106122345 YYYYMMDDHH24MI 201106122357 YYYYMMDDHH24MI | sort ↵ SESSION_ID HIT_ID 20110612234046 1772475805 20110612234046 1772475807 20110612234046 1772475809 20110612234046 1772475811 20110612234046 1772475813 ...
- 13. Highlights works with wc -l & sort (Laziness)
- 14. works with parameter binding (Boldness)
- 15. purify the SQL with limited punctuaction (Impatience)
- 16. Camel coding PERL5LIB=/proj/Web/EMIS/Modules perl -MEMIS::Database -le '($s= do{$d=EMIS::Database::gethandle(q(CDB)); $d->do(q(begin; nls_format_setting; end;)); $d}->prepare_cached(join q(),<STDIN>))->execute(@ARGV); $,=qq(\t); print STDERR @{$s->{NAME}}; print @r while @r=$s->fetchrow_array; $d->disconnect' $*
- 18. -le ' ... '
- 19. $s = do { $d=...; ...; $d } -> prepare_cached( join q(),<STDIN>)
- 20. ( $s = ... ) -> excute ( @ARGV );
- 21. $, = qq( \t );
- 23. print @r while @r=$s->fetchrow_array;
- 24. emp #!/usr/bin/perl -l use DBI; $s = do { DBI-> connect ( q(DBI:mysql:database=employees) , q() , q() ); }->prepare_cached( join ( q() ,<>) ); $s->execute ( @ARGV ); $, = qq( \t ) ; print STDERR @{$s->{ NAME }} ; print @r while @r = $s->fetchrow_array ;
- 25. Work Horse But I want query more than one DB ... Can you send me another column? Make a comma seperated list in one column ...
- 26. Report Driven Report binding variables no longer in @ARGV
- 27. SQL no longer in STDIN
- 28. Here comes loop
- 29. Running faster by prepare $s=$d->prepare_cached(do { open(SQL, q(<), shift); join(q(),<SQL>) });
- 30. $s->execute(@F);
- 32. @x = map {q()} @r unless @x;
- 34. emp-for #!/usr/bin/perl -wlan use DBI; use IO::Handle; BEGIN { $s = do { DBI-> connect ( q(DBI:mysql:database=employees) , q() , q() ); }->prepare_cached( do { open ( SQL , q(<) , shift ); join ( q() , <SQL> ) }); autoflush STDOUT 1 ; $, = qq( \t ) ; } END { $s->finish ; $d->disconnect ; close SQL ; } $s->execute ( @F ); if ( @r = $s->fetchrow_array ) { print @r ; @x = map { q() } @r unless @x } else { print @x }
- 35. How to list last deptartment? $ echo 'select emp_no from employees limit 3'|emp 2>/dev/null ↵ 10001 10002 10003 $ echo 'select emp_no from employees limit 3'|emp 2>/dev/null| emp-for emp_dept.sql ↵ d005 d007 d004
- 36. Highlights First time in Perl script
- 38. Easier than outer join
- 40. Demo data replace bofc < x.sql | tee x.bak | do-bofc-for.pl y.sql Backup and update in one line
- 41. Avoid the "no where" update fault
- 42. Save a lot of coding with perl -lan
- 43. Or compose the code for debugging purpose
- 44. Extensions Merge Rotate Wrap
- 45. merge-tab @f= map { IO::File->new($_) } @ARGV;
- 46. map { $_->getline } @f
- 47. join (qq(\t), map { m{(.*)} && $1 } ...
- 48. print ... until m{^\t+$}
- 51. END{ ... }
- 53. print join qq(\t), @x while @x=$ea->();
- 54. Demo usage How to describe a wide table? With sample data attached?
- 55. Columns $ echo 'select DATA_TYPE, CHARACTER_MAXIMUM_LENGTH from information_schema.columns where table_name=?'| emp employees | tee emp-desc ↵ DATA_TYPE CHARACTER_MAXIMUM_LENGTH int date varchar 14 varchar 16 enum 1 date
- 56. Demo Row $ echo 'select * from employees limit 1' | emp 2>&1 | row2col | tee emp-data ↵ emp_no 10001 birth_date 1953-09-02 first_name Georgi last_name Facello gender M hire_date 1986-06-26
- 57. And now? Run merge-tab over the two files $ merge-tab emp.data emp.desc ↵ emp_no 10001 int birth_date 1953-09-02 date first_name Georgi varchar 14 last_name Facello varchar 16 gender M enum 1 hire_date 1986-06-26 date
- 58. 2excel & 2csv perl -MSpreadsheet::WriteExcel
- 59. $s->write_unicode($.-1, $_, encode q(utf16), decode q(utf8), $F[$_])
- 61. 2zip BEGIN { $z=Archive::Zip->new()}
- 64. Thanks Any Question? http://weibo.com/saved2serve