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

Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.4 by root, Sun Nov 26 21:04:22 2000 UTC vs.
Revision 1.34 by root, Mon Jan 9 06:10:40 2006 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 $st = 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
22	use DBI;	44	use DBI ();
23
24	#use PApp::Exception; # not yet used
25		45
26	BEGIN {	46	BEGIN {
27	use base Exporter;	47	use base qw(Exporter DynaLoader);
28		48
29	$VERSION = 0.11;	49	$VERSION = '1.01';
30	@EXPORT = qw(	50	@EXPORT = qw(
31	sql_exec sql_fetch sql_fetchall sql_exists sql_insertid $sql_exec	51	sql_exec sql_fetch sql_fetchall sql_exists sql_insertid $sql_exec
		52	sql_uexec sql_ufetch sql_ufetchall sql_uexists
32	);	53	);
33	@EXPORT_OK = qw(	54	@EXPORT_OK = qw(
34	connect_cached	55	connect_cached
35	);	56	);
36		57
37	require XSLoader;	58	bootstrap PApp::SQL $VERSION;
38	XSLoader::load PApp::SQL, $VERSION;
39	}	59	}
40		60
41	our $sql_exec; # last result of sql_exec's execute call	61	our $sql_exec; # last result of sql_exec's execute call
42	our $DBH; # the default database handle	62	our $DBH; # the default database handle
43	our $database; # the current SQL::Database object, if applicable	63	our $Database; # the current SQL::Database object, if applicable
44		64
45	our %dbcache;	65	our %dbcache;
		66
		67	=head2 Global Variables
		68
		69	=over 4
		70
		71	=item $sql_exec
		72
		73	Since the C<sql_exec> family of functions return a statement handle there
		74	must be another way to test the return value of the C<execute> call. This
		75	global variable contains the result of the most recent call to C<execute>
		76	done by this module.
		77
		78	=item $PApp::SQL::DBH
		79
		80	The default database handle used by this module if no C<$DBH> was
		81	specified as argument. See C<sql_exec> for a discussion.
		82
		83	=item $PApp::SQL::Database
		84
		85	The current default C<PApp::SQL::Database>-object. Future versions might
		86	automatically fall back on this database and create database handles from
		87	it if neccessary. At the moment this is not used by this module but might
		88	be nice as a placeholder for the database object that corresponds to
		89	$PApp::SQL::DBH.
		90
		91	=back
		92
		93	=head2 Functions
		94
		95	=over 4
46		96
47	=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect	97	=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect
48		98
49	(not exported by by default)	99	(not exported by by default)
50		100
51	Connect to the database given by C<($dsn,$user,$pass)>, while using the	101	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	102	flags from C<$flags>. These are just the same arguments as given to
53	C<DBI->connect>.	103	C<DBI->connect>.
54		104
55	The database handle will be cached under the unique id C<$id>. If the same	105	The database handle will be cached under the unique id
56	id is requested later, the cached handle will be checked (using ping), and	106	C<$id\|$dsn\|$user\|$pass>. If the same id is requested later, the
		107	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	108	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	109	module name to the id to make it "more" unique. Things like __PACKAGE__ .
59	__PACKAGE__ . __LINE__ work fine as well).	110	__LINE__ work fine as well).
		111
		112	The reason C<$id> is necessary is that you might specify special connect
		113	arguments or special flags, or you might want to configure your $DBH
		114	differently than maybe other applications requesting the same database
		115	connection. If none of this is necessary for your application you can
		116	leave C<$id> empty (i.e. "").
60		117
61	If specified, C<$connect> is a callback (e.g. a coderef) that will be	118	If specified, C<$connect> is a callback (e.g. a coderef) that will be
62	called each time a new connection is being established, with the new	119	called each time a new connection is being established, with the new
63	C<$dbh> as first argument.	120	C<$dbh> as first argument.
64		121
65	Examples:	122	Examples:
66		123
67	# try your luck opening the papp database without access info	124	# try your luck opening the papp database without access info
68	$dbh = connect_cached __FILE__, "DBI:mysql:papp";	125	$dbh = connect_cached __FILE__, "DBI:mysql:papp";
		126
		127	Mysql-specific behaviour: The default setting of
		128	C<mysql_client_found_rows> is TRUE, you can overwrite this, though.
69		129
70	=cut	130	=cut
71		131
72	sub connect_cached {	132	sub connect_cached {
73	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;	133	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;
74	# the following line is duplicated in PApp::SQL::Database::new	134	# the following line is duplicated in PApp::SQL::Database::new
75	$id = "$id\0$dsn\0$user\0$pass";	135	$id = "$id\0$dsn\0$user\0$pass";
76	unless ($dbcache{$id} && $dbcache{$id}->ping) {	136	unless ($dbcache{$id} && $dbcache{$id}->ping) {
77	#warn "connecting to ($dsn\|$user\|$pass\|$flags)\n";#d#
78	# first, nuke our cache (sooory ;)	137	# first, nuke our statement cache (sooory ;)
79	cachesize cachesize 0;	138	cachesize cachesize 0;
		139
		140	# then make mysql behave more standardly by default
		141	$dsn =~ /^[Dd][Bb][Ii]:mysql:/
		142	and $dsn !~ /;mysql_client_found_rows/
		143	and $dsn .= ";mysql_client_found_rows=1";
		144
80	# then connect anew	145	# then connect anew
81	$dbcache{$id} =	146	$dbcache{$id} =
82	eval { DBI->connect($dsn, $user, $pass, $flags) }	147	eval { DBI->connect($dsn, $user, $pass, $flags) }
83	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }	148	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }
84	\|\| die "$DBI::errstr\n";	149	\|\| die "unable to connect to database $dsn: $DBI::errstr\n";
85	$connect->($dbcache{$id}) if $connect;	150	$connect->($dbcache{$id}) if $connect;
86	}	151	}
87	$dbcache{$id};	152	$dbcache{$id};
88	}	153	}
89		154
90	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]	155	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]
		156
		157	=item $sth = sql_uexec <see sql_exec>
91		158
92	C<sql_exec> is the most important and most-used function in this module.	159	C<sql_exec> is the most important and most-used function in this module.
93		160
94	Runs the given sql command with the given parameters and returns the	161	Runs the given sql command with the given parameters and returns the
95	statement handle. The command and the statement handle will be cached	162	statement handle. The command and the statement handle will be cached
96	(with the database handle and the sql string as key), so prepare will be	163	(with the database handle and the sql string as key), so prepare will be
97	called only once for each distinct sql call (please keep in mind that the	164	called only once for each distinct sql call (please keep in mind that the
98	returned statement will always be the same, so, if you call C<sql_exec>	165	returned statement will always be the same, so, if you call C<sql_exec>
99	with the same dbh and sql-statement twice (e.g. in a subroutine you	166	with the same dbh and sql-statement twice (e.g. in a subroutine you
100	called), the statement handle for the first call mustn't be used.	167	called), the statement handle for the first call mustn't not be in use
		168	anymore, as the subsequent call will re-use the handle.
101		169
102	The database handle (the first argument) is optional. If it is missing,	170	The database handle (the first argument) is optional. If it is missing,
103	C<sql_exec> first tries to use the variable C<$DBH> in the current (=	171	it tries to use database handle in C<$PApp::SQL::DBH>, which you can set
104	calling) package and, if that fails, it tries to use database handle in	172	before calling these functions. NOTICE: future and former versions of
105	C<$PApp::SQL::DBH>, which you can set before calling these functions.	173	PApp::SQL might also look up the global variable C<$DBH> in the callers
		174	package.
		175
		176	=begin comment
		177
		178	If it is missing, C<sql_exec> first tries to use the variable C<$DBH>
		179	in the current (= calling) package and, if that fails, it tries to use
		180	database handle in C<$PApp::SQL::DBH>, which you can set before calling
		181	these functions.
		182
		183	=end comment
106		184
107	The actual return value from the C<$sth->execute> call is stored in the	185	The actual return value from the C<$sth->execute> call is stored in the
108	package-global (and exported) variable C<$sql_exec>.	186	package-global (and exported) variable C<$sql_exec>.
109		187
110	If any error occurs C<sql_exec> will throw an exception.	188	If any error occurs C<sql_exec> will throw an exception.
		189
		190	C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
		191	UTF-8 before calling the C<execute> method.
111		192
112	Examples:	193	Examples:
113		194
114	# easy one	195	# easy one
115	my $st = sql_exec "select name, id from table where id = ?", $id;	196	my $st = sql_exec "select name, id from table where id = ?", $id;
125	sql_exec $dbh, "update file set name = ?", "oops.txt";	206	sql_exec $dbh, "update file set name = ?", "oops.txt";
126		207
127		208
128	=item sql_fetch <see sql_exec>	209	=item sql_fetch <see sql_exec>
129		210
		211	=item sql_ufetch <see sql_uexec>
		212
130	Execute a sql-statement and fetch the first row of results. Depending on	213	Execute an sql-statement and fetch the first row of results. Depending on
131	the caller context the row will be returned as a list (array context), or	214	the caller context the row will be returned as a list (array context), or
132	just the first columns. In table form:	215	just the first columns. In table form:
133		216
134	CONTEXT RESULT	217	CONTEXT RESULT
135	void ()	218	void ()
…		…
146		229
147	my($name, $amount) = sql_fetch "select ...", args...	230	my($name, $amount) = sql_fetch "select ...", args...
148		231
149	... and it's still quite fast unless you fetch large amounts of data.	232	... and it's still quite fast unless you fetch large amounts of data.
150		233
		234	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		235	UTF-8 and forces all result values to UTF-8 (this does I<not> include result
		236	parameters, only return values. Using bind variables in conjunction with
		237	sql_u* functions might result in undefined behaviour - we use UTF-8 on
		238	bind-variables at execution time and it seems to work on DBD::mysql as it
		239	ignores the UTF-8 bit completely. Which just means that that DBD-driver is
		240	broken).
		241
151	=item sql_fetchall <see sql_exec>	242	=item sql_fetchall <see sql_exec>
		243
		244	=item sql_ufetchall <see sql_uexec>
152		245
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	246	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	247	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	248	list context makes sense), but the result still depends on the number of
156	columns in the result:	249	columns in the result:
…		…
168		261
169	for (sql_fetchall "select name, age, place from user") {	262	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	263	my ($name, $age, $place) = @$_;
171	}	264	}
172		265
		266	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		267	values to UTF-8 and forces all result values to UTF-8 (see the caveats in
		268	the description of C<sql_ufetch>, though).
		269
173	=item sql_exists "<table> where ...", args...	270	=item sql_exists "<table_references> where <where_condition>...", args...
		271
		272	=item sql_uexists <see sql_exists>
174		273
175	Check wether the result of the sql-statement "select xxx from	274	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	275	$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	276	"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	277	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	278	should be quite fast.
		279
		280	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		281	UTF-8.
180		282
181	Examples:	283	Examples:
182		284
183	print "user 7 exists!\n"	285	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	286	if sql_exists "user where id = ?", 7;
…		…
188		290
189	=cut	291	=cut
190		292
191	=item $lastid = sql_insertid $sth	293	=item $lastid = sql_insertid $sth
192		294
193	Returns the last automatically created key value (e.g. for mysql	295	Returns the last automatically created key value. It must be executed
194	AUTO_INCREMENT or sybase IDENTITY fields). It must be executed directly
195	after executing the insert statement that created it.	296	directly after executing the insert statement that created it. This is
		297	what is actually returned for various databases. If your database is
		298	missing, please send me an e-mail on how to implement this ;)
		299
		300	mysql: first C<AUTO_INCREMENT> column set to NULL
		301	postgres: C<oid> column (is there a way to get the last SERIAL?)
		302	sybase: C<IDENTITY> column of the last insert (slow)
		303	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		304	sqlite: C<last_insert_rowid()>
		305
		306	Except for sybase, this does not require a server access.
196		307
197	=cut	308	=cut
198		309
199	sub sql_insertid($) {	310	sub sql_insertid($) {
200	my $sth = shift or die "sql_insertid requires a statement handle";	311	my $sth = shift or die "sql_insertid requires a statement handle";
201	my $dbh = $sth->{Database};	312	my $dbh = $sth->{Database};
202	my $driver = $dbh->{Driver}{Name};	313	my $driver = $dbh->{Driver}{Name};
203		314
204	$driver eq "mysql" and return $sth->{mysql_insertid};	315	$driver eq "mysql" and return $sth->{mysql_insertid};
		316	$driver eq "Pg" and return $sth->{pg_oid_status};
205	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');	317	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
206	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];	318	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
		319	$driver eq "SQLite" and return sql_fetch($dbh, 'SELECT last_insert_rowid ()');
207		320
208	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";	321	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
209	}	322	}
210		323
211	=item [old-size] = cachesize [new-size]	324	=item [old-size] = cachesize [new-size]
212		325
213	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	326	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
214	default is somewhere around 50 (= the 50 last recently used statements	327	default is somewhere around 50 (= the 50 last recently used statements
215	will be cached). It shouldn't be too large, since a simple linear listed	328	will be cached). It shouldn't be too large, since a simple linear list
216	is used for the cache at the moment (which, for small (<100) cache sizes	329	is used for the cache at the moment (which, for small (<100) cache sizes
217	is actually quite fast).	330	is actually quite fast).
218		331
219	The function always returns the cache size in effect I<before> the call,	332	The function always returns the cache size in effect I<before> the call,
220	so, to nuke the cache (for example, when a database connection has died	333	so, to nuke the cache (for example, when a database connection has died
…		…
225		338
226	=cut	339	=cut
227		340
228	=item reinitialize [not exported]	341	=item reinitialize [not exported]
229		342
230	Clears any internal caches (statement cache, database handle cache).	343	Clears any internal caches (statement cache, database handle
		344	cache). Should be called after C<fork> and other accidents that invalidate
		345	database handles.
231		346
232	=cut	347	=cut
233		348
234	sub reinitialize {	349	sub reinitialize {
235	cachesize cachesize 0;	350	cachesize cachesize 0;
236	for (values %dbcache) {	351	for (values %dbcache) {
237	eval { $_->disconnect };	352	eval { $_->{InactiveDestroy} = 1 };
238	}	353	}
239	undef %dbcache;	354	undef %dbcache;
240	}	355	}
241		356
242	=back	357	=back
243		358
244	=cut	359	=cut
245		360
		361	reinitialize;
		362
246	package PApp::SQL::Database;	363	package PApp::SQL::Database;
247		364
248	=head2 THE DATABASE CLASS	365	=head2 The Database Class
249		366
250	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	367	Again (sigh) the problem of persistency. What do you do when you have
251	that contains (or should contain) a database handle? Short answer: you don't. Long answer:	368	to serialize on object that contains (or should contain) a database
		369	handle? Short answer: you don't. Long answer: you can embed the necessary
252	you can embed the necessary information to recreate the dbh when needed.	370	information to recreate the dbh when needed.
253		371
254	The C<PApp::SQL::Database> class does that, in a relatively efficient	372	The C<PApp::SQL::Database> class does that, in a relatively efficient
255	fashion: the overhead is currently a single method call per access (you	373	fashion: the overhead is currently a single method call per access (you
256	can cache the real dbh if you want).	374	can cache the real dbh if you want).
257		375
…		…
297		415
298	=item $db->dsn	416	=item $db->dsn
299		417
300	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	418	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
301		419
		420	=item $db->login
		421
		422	Return the login name.
		423
		424	=item $db->password
		425
		426	Return the password (emphasizing the fact that the password is stored plaintext ;)
		427
302	=cut	428	=cut
303		429
304	sub dsn($) {	430	sub dsn($) {
305	my $self = shift;	431	my $self = shift;
306	$self->[1][1];	432	(split /\x00/, $self->[0])[1];
		433	}
		434
		435	sub login($) {
		436	my $self = shift;
		437	(split /\x00/, $self->[0])[2];
		438	}
		439
		440	sub password($) {
		441	my $self = shift;
		442	(split /\x00/, $self->[0])[3];
307	}	443	}
308		444
309	=back	445	=back
310		446
311	=cut	447	=cut
312		448
313	reinitialize;
314
315	1;	449	1;
316		450
317	=head1 BUGS
318
319	As of this writing, sql_fetch and sql_fetchall are not very well tested
320	(they were just re-written in C).
321
322	sql_exists could be faster (it is written very ugly to not change the
323	current package).
324
325	=head1 SEE ALSO	451	=head1 SEE ALSO
326		452
327	L<PApp>.	453	L<PApp>.
328		454
329	=head1 AUTHOR	455	=head1 AUTHOR
330		456
331	Marc Lehmann <pcg@goof.com>	457	Marc Lehmann <schmorp@schmorp.de>
332	http://www.goof.com/pcg/marc/	458	http://home.schmorp.de/
333		459
334	=cut	460	=cut
335		461

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Comparing PApp-SQL/SQL.pm (file contents): Revision 1.4 by root, Sun Nov 26 21:04:22 2000 UTC vs. Revision 1.34 by root, Mon Jan 9 06:10:40 2006 UTC

Diff Legend

Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.4 by root, Sun Nov 26 21:04:22 2000 UTC vs.
Revision 1.34 by root, Mon Jan 9 06:10:40 2006 UTC