[ViewVC] Diff of: cvs/PApp-SQL/SQL.pm

Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.2 by root, Wed Nov 1 03:22:07 2000 UTC vs.
Revision 1.38 by root, Sat Jun 20 21:03:50 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	PApp::SQL - absolutely easy yet fast and powerful sql access	3	PApp::SQL - absolutely easy yet fast and powerful sql access.
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use PApp::SQL;	7	use PApp::SQL;
8	# to be written	8
		9	my $st = sql_exec $DBH, "select ... where a = ?", $a;
		10
		11	local $DBH = <database handle>;
		12	my $st = sql_exec \my($bind_a, $bind_b), "select a,b ...";
		13	my $id = sql_insertid
		14	sql_exec "insert into ... values (?, ?)", $v1, $v2;
		15	my $a = sql_fetch "select a from ...";
		16	sql_fetch \my($a, $b), "select a,b ...";
		17
		18	sql_exists "table where name like 'a%'"
		19	or die "a* required but not existent";
		20
		21	my $db = new PApp::SQL::Database "", "DBI:mysql:test", "user", "pass";
		22	local $PApp::SQL::DBH = $db->checked_dbh; # does 'ping'
		23
		24	sql_exec $db->dbh, "select ...";
9		25
10	=head1 DESCRIPTION	26	=head1 DESCRIPTION
11		27
12	This module provides you with easy-to-use functions to execute sql	28	This module provides you with easy-to-use functions to execute sql
13	commands (using DBI). Despite being easy to use, they are also quite	29	commands (using DBI). Despite being easy to use, they are also quite
14	efficient and allow you to write faster programs in less lines of code.	30	efficient and allow you to write faster programs in less lines of code. It
		31	should work with anything from perl-5.004_01 onwards, but I only support
		32	5.005+. UTF8 handling (the C<sql_u*> family of functions) will only be
		33	effective with perl version 5.006 and beyond.
15		34
16	=over 4	35	If the descriptions here seem terse or if you always wanted to know
		36	what PApp is then have a look at the PApp module which uses this module
		37	extensively but also provides you with a lot more gimmicks to play around
		38	with to help you create cool applications ;)
17		39
18	=cut	40	=cut
19		41
20	package PApp::SQL;	42	package PApp::SQL;
21		43
		44	use Carp ();
22	use DBI;	45	use DBI ();
23
24	#use PApp::Exception; # not yet used
25		46
26	BEGIN {	47	BEGIN {
27	use base Exporter;	48	use base qw(Exporter DynaLoader);
28		49
29	$VERSION = 0.1;	50	$VERSION = '1.04';
30	@EXPORT = qw(	51	@EXPORT = qw(
31	sql_exec sql_fetch sql_fetchall sql_exists sql_insertid $sql_exec	52	sql_exec sql_fetch sql_fetchall sql_exists sql_insertid $sql_exec
		53	sql_uexec sql_ufetch sql_ufetchall sql_uexists
32	);	54	);
33	@EXPORT_OK = qw(	55	@EXPORT_OK = qw(
34	connect_cached	56	connect_cached
35	);	57	);
36		58
37	require XSLoader;	59	bootstrap PApp::SQL $VERSION;
38	XSLoader::load PApp::SQL, $VERSION;
39	}	60	}
40		61
41	our $sql_exec; # last result of sql_exec's execute call	62	our $sql_exec; # last result of sql_exec's execute call
42	our $DBH; # the default database handle	63	our $DBH; # the default database handle
43	our $database; # the current SQL::Database object, if applicable	64	our $Database; # the current SQL::Database object, if applicable
44		65
45	our %dbcache;	66	our %dbcache;
		67
		68	=head2 Global Variables
		69
		70	=over 4
		71
		72	=item $sql_exec
		73
		74	Since the C<sql_exec> family of functions return a statement handle there
		75	must be another way to test the return value of the C<execute> call. This
		76	global variable contains the result of the most recent call to C<execute>
		77	done by this module.
		78
		79	=item $PApp::SQL::DBH
		80
		81	The default database handle used by this module if no C<$DBH> was
		82	specified as argument. See C<sql_exec> for a discussion.
		83
		84	=item $PApp::SQL::Database
		85
		86	The current default C<PApp::SQL::Database>-object. Future versions might
		87	automatically fall back on this database and create database handles from
		88	it if neccessary. At the moment this is not used by this module but might
		89	be nice as a placeholder for the database object that corresponds to
		90	$PApp::SQL::DBH.
		91
		92	=back
		93
		94	=head2 Functions
		95
		96	=over 4
46		97
47	=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect	98	=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect
48		99
49	(not exported by by default)	100	(not exported by by default)
50		101
51	Connect to the database given by C<($dsn,$user,$pass)>, while using the	102	Connect to the database given by C<($dsn,$user,$pass)>, while using the
52	flags from C<$flags>. These are just the same arguments as given to	103	flags from C<$flags>. These are just the same arguments as given to
53	C<DBI->connect>.	104	C<DBI->connect>.
54		105
55	The database handle will be cached under the unique id C<$id>. If the same	106	The database handle will be cached under the unique id
56	id is requested later, the cached handle will be checked (using ping), and	107	C<$id\|$dsn\|$user\|$pass>. If the same id is requested later, the
		108	cached handle will be checked (using ping), and the connection will
57	the connection will be re-established if necessary (be sure to prefix your	109	be re-established if necessary (be sure to prefix your application or
58	application or module name to the id to make it "more" unique. Things like	110	module name to the id to make it "more" unique. Things like __PACKAGE__ .
59	__PACKAGE__ . __LINE__ work fine as well).	111	__LINE__ work fine as well).
		112
		113	The reason C<$id> is necessary is that you might specify special connect
		114	arguments or special flags, or you might want to configure your $DBH
		115	differently than maybe other applications requesting the same database
		116	connection. If none of this is necessary for your application you can
		117	leave C<$id> empty (i.e. "").
60		118
61	If specified, C<$connect> is a callback (e.g. a coderef) that will be	119	If specified, C<$connect> is a callback (e.g. a coderef) that will be
62	called each time a new connection is being established, with the new	120	called each time a new connection is being established, with the new
63	C<$dbh> as first argument.	121	C<$dbh> as first argument.
64		122
65	Examples:	123	Examples:
66		124
67	# try your luck opening the papp database without access info	125	# try your luck opening the papp database without access info
68	$dbh = connect_cached __FILE__, "DBI:mysql:papp";	126	$dbh = connect_cached __FILE__, "DBI:mysql:papp";
		127
		128	Mysql-specific behaviour: The default setting of
		129	C<mysql_client_found_rows> is TRUE, you can overwrite this, though.
69		130
70	=cut	131	=cut
71		132
72	sub connect_cached {	133	sub connect_cached {
73	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;	134	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;
74	# the following line is duplicated in PApp::SQL::Database::new	135	# the following line is duplicated in PApp::SQL::Database::new
75	$id = "$id\0$dsn\0$user\0$pass";	136	$id = "$id\0$dsn\0$user\0$pass";
76	unless ($dbcache{$id} && $dbcache{$id}->ping) {	137	unless ($dbcache{$id} && $dbcache{$id}->ping) {
77	#warn "connecting to ($dsn\|$user\|$pass\|$flags)\n";#d#
78	# first, nuke our cache (sooory ;)	138	# first, nuke our statement cache (sooory ;)
79	cachesize cachesize 0;	139	cachesize cachesize 0;
		140
		141	# then make mysql behave more standardly by default
		142	$dsn =~ /^[Dd][Bb][Ii]:mysql:/
		143	and $dsn !~ /;mysql_client_found_rows/
		144	and $dsn .= ";mysql_client_found_rows=1";
		145
80	# then connect anew	146	# then connect anew
81	$dbcache{$id} =	147	$dbcache{$id} =
82	eval { DBI->connect($dsn, $user, $pass, $flags) }	148	eval { DBI->connect($dsn, $user, $pass, $flags) }
83	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }	149	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }
84	\|\| die "$DBI::errstr\n";	150	\|\| Carp::croak "unable to connect to database $dsn: $DBI::errstr\n";
85	$connect->($dbcache{$id}) if $connect;	151	$connect->($dbcache{$id}) if $connect;
86	}	152	}
87	$dbcache{$id};	153	$dbcache{$id};
88	}	154	}
89		155
90	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]	156	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]
		157
		158	=item $sth = sql_uexec <see sql_exec>
91		159
92	C<sql_exec> is the most important and most-used function in this module.	160	C<sql_exec> is the most important and most-used function in this module.
93		161
94	Runs the given sql command with the given parameters and returns the	162	Runs the given sql command with the given parameters and returns the
95	statement handle. The command and the statement handle will be cached	163	statement handle. The command and the statement handle will be cached
96	(with the database handle and the sql string as key), so prepare will be	164	(with the database handle and the sql string as key), so prepare will be
97	called only once for each distinct sql call (please keep in mind that the	165	called only once for each distinct sql call (please keep in mind that the
98	returned statement will always be the same, so, if you call C<sql_exec>	166	returned statement will always be the same, so, if you call C<sql_exec>
99	with the same dbh and sql-statement twice (e.g. in a subroutine you	167	with the same dbh and sql-statement twice (e.g. in a subroutine you
100	called), the statement handle for the first call mustn't be used.	168	called), the statement handle for the first call mustn't not be in use
		169	anymore, as the subsequent call will re-use the handle.
101		170
102	The database handle (the first argument) is optional. If it is missing,	171	The database handle (the first argument) is optional. If it is missing,
103	C<sql_exec> first tries to use the variable C<$DBH> in the current (=	172	it tries to use database handle in C<$PApp::SQL::DBH>, which you can set
104	calling) package and, if that fails, it tries to use database handle in	173	before calling these functions. NOTICE: future and former versions of
105	C<$PApp::SQL::DBH>, which you can set before calling these functions.	174	PApp::SQL might also look up the global variable C<$DBH> in the callers
		175	package.
		176
		177	=begin comment
		178
		179	If it is missing, C<sql_exec> first tries to use the variable C<$DBH>
		180	in the current (= calling) package and, if that fails, it tries to use
		181	database handle in C<$PApp::SQL::DBH>, which you can set before calling
		182	these functions.
		183
		184	=end comment
106		185
107	The actual return value from the C<$sth->execute> call is stored in the	186	The actual return value from the C<$sth->execute> call is stored in the
108	package-global (and exported) variable C<$sql_exec>.	187	package-global (and exported) variable C<$sql_exec>.
109		188
110	If any error occurs C<sql_exec> will throw an exception.	189	If any error occurs C<sql_exec> will throw an exception.
		190
		191	C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
		192	UTF-8 before calling the C<execute> method.
111		193
112	Examples:	194	Examples:
113		195
114	# easy one	196	# easy one
115	my $st = sql_exec "select name, id from table where id = ?", $id;	197	my $st = sql_exec "select name, id from table where id = ?", $id;
125	sql_exec $dbh, "update file set name = ?", "oops.txt";	207	sql_exec $dbh, "update file set name = ?", "oops.txt";
126		208
127		209
128	=item sql_fetch <see sql_exec>	210	=item sql_fetch <see sql_exec>
129		211
		212	=item sql_ufetch <see sql_uexec>
		213
130	Execute a sql-statement and fetch the first row of results. Depending on	214	Execute an sql-statement and fetch the first row of results. Depending on
131	the caller context the row will be returned as a list (array context), or	215	the caller context the row will be returned as a list (array context), or
132	just the first columns. In table form:	216	just the first columns. In table form:
133		217
134	CONTEXT RESULT	218	CONTEXT RESULT
135	void ()	219	void ()
…		…
146		230
147	my($name, $amount) = sql_fetch "select ...", args...	231	my($name, $amount) = sql_fetch "select ...", args...
148		232
149	... and it's still quite fast unless you fetch large amounts of data.	233	... and it's still quite fast unless you fetch large amounts of data.
150		234
		235	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		236	UTF-8 and forces all result values to UTF-8 (this does I<not> include result
		237	parameters, only return values. Using bind variables in conjunction with
		238	sql_u* functions might result in undefined behaviour - we use UTF-8 on
		239	bind-variables at execution time and it seems to work on DBD::mysql as it
		240	ignores the UTF-8 bit completely. Which just means that that DBD-driver is
		241	broken).
		242
151	=item sql_fetchall <see sql_exec>	243	=item sql_fetchall <see sql_exec>
		244
		245	=item sql_ufetchall <see sql_uexec>
152		246
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	247	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	248	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	249	list context makes sense), but the result still depends on the number of
156	columns in the result:	250	columns in the result:
…		…
168		262
169	for (sql_fetchall "select name, age, place from user") {	263	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	264	my ($name, $age, $place) = @$_;
171	}	265	}
172		266
		267	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		268	values to UTF-8 and forces all result values to UTF-8 (see the caveats in
		269	the description of C<sql_ufetch>, though).
		270
173	=item sql_exists "<table> where ...", args...	271	=item sql_exists "<table_references> where <where_condition>...", args...
		272
		273	=item sql_uexists <see sql_exists>
174		274
175	Check wether the result of the sql-statement "select xxx from	275	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	276	$first_argument" would be empty or not (that is, imagine the string
177	"select from" were prepended to your statement (it isn't)). Should work	277	"select * from" were prepended to your statement (it isn't)). Should work
178	with every database but can be quite slow, except on mysql, where this	278	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	279	should be quite fast.
		280
		281	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		282	UTF-8.
180		283
181	Examples:	284	Examples:
182		285
183	print "user 7 exists!\n"	286	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	287	if sql_exists "user where id = ?", 7;
…		…
186	die "duplicate key"	289	die "duplicate key"
187	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";	290	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";
188		291
189	=cut	292	=cut
190		293
191	# uncodumented, since unportable (only works with DBH even!). yet it is exported (aaargh!)	294	=item $lastid = sql_insertid $sth
		295
		296	Returns the last automatically created key value. It must be executed
		297	directly after executing the insert statement that created it. This is
		298	what is actually returned for various databases. If your database is
		299	missing, please send me an e-mail on how to implement this ;)
		300
		301	mysql: first C<AUTO_INCREMENT> column set to NULL
		302	postgres: C<oid> column (is there a way to get the last SERIAL?)
		303	sybase: C<IDENTITY> column of the last insert (slow)
		304	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		305	sqlite: C<last_insert_rowid()>
		306
		307	Except for sybase, this does not require a server access.
		308
		309	=cut
		310
192	sub sql_insertid {	311	sub sql_insertid($) {
193	$DBH->{mysql_insertid};	312	my $sth = shift or Carp::croak "sql_insertid requires a statement handle";
		313	my $dbh = $sth->{Database};
		314	my $driver = $dbh->{Driver}{Name};
		315
		316	$driver eq "mysql" and return $sth->{mysql_insertid};
		317	$driver eq "Pg" and return $sth->{pg_oid_status};
		318	$driver eq "Sybase" and return sql_fetch ($dbh, 'SELECT @@IDENTITY');
		319	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
		320	$driver eq "SQLite" and return sql_fetch ($dbh, 'SELECT last_insert_rowid ()');
		321
		322	Carp::croak "sql_insertid does not support the dbd driver '$driver', at";
194	}	323	}
195		324
196	=item [old-size] = cachesize [new-size]	325	=item [old-size] = cachesize [new-size]
197		326
198	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	327	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
199	default is somewhere around 50 (= the 50 last recently used statements	328	default is somewhere around 50 (= the 50 last recently used statements
200	will be cached). It shouldn't be too large, since a simple linear listed	329	will be cached). It shouldn't be too large, since a simple linear list
201	is used for the cache at the moment (which, for small (<100) cache sizes	330	is used for the cache at the moment (which, for small (<100) cache sizes
202	is actually quite fast).	331	is actually quite fast).
203		332
204	The function always returns the cache size in effect I<before> the call,	333	The function always returns the cache size in effect I<before> the call,
205	so, to nuke the cache (for example, when a database connection has died	334	so, to nuke the cache (for example, when a database connection has died
…		…
210		339
211	=cut	340	=cut
212		341
213	=item reinitialize [not exported]	342	=item reinitialize [not exported]
214		343
215	Clears any internal caches (statement cache, database handle cache).	344	Clears any internal caches (statement cache, database handle
		345	cache). Should be called after C<fork> and other accidents that invalidate
		346	database handles.
216		347
217	=cut	348	=cut
218		349
219	sub reinitialize {	350	sub reinitialize {
220	cachesize cachesize 0;	351	cachesize cachesize 0;
221	for (values %dbcache) {	352	for (values %dbcache) {
222	eval { $_->disconnect };	353	eval { $_->{InactiveDestroy} = 1 };
223	}	354	}
224	undef %dbcache;	355	undef %dbcache;
225	}	356	}
226		357
227	=back	358	=back
228		359
229	=cut	360	=cut
230		361
		362	reinitialize;
		363
231	package PApp::SQL::Database;	364	package PApp::SQL::Database;
232		365
233	=head2 THE DATABASE CLASS	366	=head2 The Database Class
234		367
235	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	368	Again (sigh) the problem of persistency. What do you do when you have
236	that contains (or should contain) a database handle? Short answer: you don't. Long answer:	369	to serialize on object that contains (or should contain) a database
		370	handle? Short answer: you don't. Long answer: you can embed the necessary
237	you can embed the necessary information to recreate the dbh when needed.	371	information to recreate the dbh when needed.
238		372
239	The C<PApp::SQL::Database> class does that, in a relatively efficient	373	The C<PApp::SQL::Database> class does that, in a relatively efficient
240	fashion: the overhead is currently a single method call per access (you	374	fashion: the overhead is currently a single method call per access (you
241	can cache the real dbh if you want).	375	can cache the real dbh if you want).
242		376
…		…
275		409
276	sub checked_dbh($) {	410	sub checked_dbh($) {
277	my $dbh = $dbcache{$_[0][0]};	411	my $dbh = $dbcache{$_[0][0]};
278	$dbh && $dbh->ping	412	$dbh && $dbh->ping
279	? $dbh	413	? $dbh
280	: PApp::SQL::connect_cached((split /\x00/, $_[0][0]), $_[0][1], $_[0][2]);	414	: PApp::SQL::connect_cached((split /\x00/, $_[0][0], 4), $_[0][1], $_[0][2]);
281	}	415	}
282		416
283	=item $db->dsn	417	=item $db->dsn
284		418
285	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	419	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
		420
		421	=item $db->login
		422
		423	Return the login name.
		424
		425	=item $db->password
		426
		427	Return the password (emphasizing the fact that the password is stored plaintext ;)
286		428
287	=cut	429	=cut
288		430
289	sub dsn($) {	431	sub dsn($) {
290	my $self = shift;	432	my $self = shift;
291	$self->[1][1];	433	(split /\x00/, $self->[0])[1];
		434	}
		435
		436	sub login($) {
		437	my $self = shift;
		438	(split /\x00/, $self->[0])[2];
		439	}
		440
		441	sub password($) {
		442	my $self = shift;
		443	(split /\x00/, $self->[0])[3];
292	}	444	}
293		445
294	=back	446	=back
295		447
296	=cut	448	=cut
297		449
298	reinitialize;
299
300	1;	450	1;
301		451
302	=head1 BUGS
303
304	As of this writing, sql_fetch and sql_fetchall are not very well tested
305	(they were just re-written in C).
306
307	sql_exists could be faster (it is written very ugly to not change the
308	current package).
309
310	=head1 SEE ALSO	452	=head1 SEE ALSO
311		453
312	L<PApp>.	454	L<PApp>.
313		455
314	=head1 AUTHOR	456	=head1 AUTHOR
315		457
316	Marc Lehmann <pcg@goof.com>	458	Marc Lehmann <schmorp@schmorp.de>
317	http://www.goof.com/pcg/marc/	459	http://home.schmorp.de/
318		460
319	=cut	461	=cut
320		462

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Comparing PApp-SQL/SQL.pm (file contents): Revision 1.2 by root, Wed Nov 1 03:22:07 2000 UTC vs. Revision 1.38 by root, Sat Jun 20 21:03:50 2009 UTC

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Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.2 by root, Wed Nov 1 03:22:07 2000 UTC vs.
Revision 1.38 by root, Sat Jun 20 21:03:50 2009 UTC