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

Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.5 by root, Sat Jan 6 03:04:03 2001 UTC vs.
Revision 1.30 by stefan, Wed Jan 28 19:50:38 2004 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 = 0.143;
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 statement 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 "unable to connect to database $dsn: $DBI::errstr\n";	149	\|\| die "unable to connect to database $dsn: $DBI::errstr\n";
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...]
91		156
		157	=item $sth = sql_uexec <see sql_exec>
		158
92	C<sql_exec> is the most important and most-used function in this module.	159	C<sql_exec> is the most important and most-used function in this module.
93		160
94	Runs the given sql command with the given parameters and returns the	161	Runs the given sql command with the given parameters and returns the
95	statement handle. The command and the statement handle will be cached	162	statement handle. The command and the statement handle will be cached
96	(with the database handle and the sql string as key), so prepare will be	163	(with the database handle and the sql string as key), so prepare will be
97	called only once for each distinct sql call (please keep in mind that the	164	called only once for each distinct sql call (please keep in mind that the
98	returned statement will always be the same, so, if you call C<sql_exec>	165	returned statement will always be the same, so, if you call C<sql_exec>
99	with the same dbh and sql-statement twice (e.g. in a subroutine you	166	with the same dbh and sql-statement twice (e.g. in a subroutine you
100	called), the statement handle for the first call mustn't be used.	167	called), the statement handle for the first call mustn't not be in use
		168	anymore, as the subsequent call will re-use the handle.
101		169
102	The database handle (the first argument) is optional. If it is missing,	170	The database handle (the first argument) is optional. If it is missing,
103	C<sql_exec> first tries to use the variable C<$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	utf8 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, $amount) = sql_fetch "select ...", args...
148		231
149	... and it's still quite fast unless you fetch large amounts of data.	232	... and it's still quite fast unless you fetch large amounts of data.
150		233
		234	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		235	utf8 and forces all result values to utf8 (this does I<not> include result
		236	parameters, only return values. Using bind variables in cinjunction with
		237	sql_u* functions results in undefined behaviour - we use utf8_on on
		238	bind-variables and it seems to work on DBD::mysql which just means
		239	that that DBD-driver is broken).
		240
151	=item sql_fetchall <see sql_exec>	241	=item sql_fetchall <see sql_exec>
		242
		243	=item sql_ufetchall <see sql_uexec>
152		244
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	245	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	246	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	247	list context makes sense), but the result still depends on the number of
156	columns in the result:	248	columns in the result:
…		…
168		260
169	for (sql_fetchall "select name, age, place from user") {	261	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	262	my ($name, $age, $place) = @$_;
171	}	263	}
172		264
		265	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		266	values to utf8 and forces all result values to utf8 (see the caveats in
		267	the description of C<sql_ufetch>, though).
		268
173	=item sql_exists "<table> where ...", args...	269	=item sql_exists "<table_references> where <where_condition>...", args...
		270
		271	=item sql_uexists <see sql_exists>
174		272
175	Check wether the result of the sql-statement "select xxx from	273	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	274	$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	275	"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	276	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	277	should be quite fast.
		278
		279	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		280	utf8.
180		281
181	Examples:	282	Examples:
182		283
183	print "user 7 exists!\n"	284	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	285	if sql_exists "user where id = ?", 7;
…		…
188		289
189	=cut	290	=cut
190		291
191	=item $lastid = sql_insertid $sth	292	=item $lastid = sql_insertid $sth
192		293
193	Returns the last automatically created key value (e.g. for mysql	294	Returns the last automatically created key value. It must be executed
194	AUTO_INCREMENT or sybase IDENTITY fields). It must be executed directly
195	after executing the insert statement that created it.	295	directly after executing the insert statement that created it. This is
		296	what is actually returned for various databases. If your database is
		297	missing, please send me an e-mail on how to implement this ;)
		298
		299	mysql: first C<AUTO_INCREMENT> column set to NULL
		300	postgres: C<oid> column (is there a way to get the last SERIAL?)
		301	sybase: C<IDENTITY> column of the last insert (slow)
		302	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		303
		304	Except for sybase, this does not require a server access.
196		305
197	=cut	306	=cut
198		307
199	sub sql_insertid($) {	308	sub sql_insertid($) {
200	my $sth = shift or die "sql_insertid requires a statement handle";	309	my $sth = shift or die "sql_insertid requires a statement handle";
201	my $dbh = $sth->{Database};	310	my $dbh = $sth->{Database};
202	my $driver = $dbh->{Driver}{Name};	311	my $driver = $dbh->{Driver}{Name};
203		312
204	$driver eq "mysql" and return $sth->{mysql_insertid};	313	$driver eq "mysql" and return $sth->{mysql_insertid};
		314	$driver eq "Pg" and return $sth->{pg_oid_status};
205	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');	315	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
206	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];	316	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
207		317
208	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";	318	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
209	}	319	}
210		320
211	=item [old-size] = cachesize [new-size]	321	=item [old-size] = cachesize [new-size]
212		322
213	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	323	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	324	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	325	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	326	is used for the cache at the moment (which, for small (<100) cache sizes
217	is actually quite fast).	327	is actually quite fast).
218		328
219	The function always returns the cache size in effect I<before> the call,	329	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	330	so, to nuke the cache (for example, when a database connection has died
…		…
225		335
226	=cut	336	=cut
227		337
228	=item reinitialize [not exported]	338	=item reinitialize [not exported]
229		339
230	Clears any internal caches (statement cache, database handle cache).	340	Clears any internal caches (statement cache, database handle
		341	cache). Should be called after C<fork> and other accidents that invalidate
		342	database handles.
231		343
232	=cut	344	=cut
233		345
234	sub reinitialize {	346	sub reinitialize {
235	cachesize cachesize 0;	347	cachesize cachesize 0;
236	for (values %dbcache) {	348	for (values %dbcache) {
237	eval { $_->disconnect };	349	eval { $_->{InactiveDestroy} = 1 };
238	}	350	}
239	undef %dbcache;	351	undef %dbcache;
240	}	352	}
241		353
242	=back	354	=back
243		355
244	=cut	356	=cut
245		357
		358	reinitialize;
		359
246	package PApp::SQL::Database;	360	package PApp::SQL::Database;
247		361
248	=head2 THE DATABASE CLASS	362	=head2 THE DATABASE CLASS
249		363
250	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	364	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:	365	to serialize on object that contains (or should contain) a database
		366	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.	367	information to recreate the dbh when needed.
253		368
254	The C<PApp::SQL::Database> class does that, in a relatively efficient	369	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	370	fashion: the overhead is currently a single method call per access (you
256	can cache the real dbh if you want).	371	can cache the real dbh if you want).
257		372
…		…
297		412
298	=item $db->dsn	413	=item $db->dsn
299		414
300	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	415	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
301		416
		417	=item $db->login
		418
		419	Return the login name.
		420
		421	=item $db->password
		422
		423	Return the password (emphasizing the fact that the password is stored plaintext ;)
		424
302	=cut	425	=cut
303		426
304	sub dsn($) {	427	sub dsn($) {
305	my $self = shift;	428	my $self = shift;
306	$self->[1][1];	429	(split /\x00/, $self->[0])[1];
		430	}
		431
		432	sub login($) {
		433	my $self = shift;
		434	(split /\x00/, $self->[0])[2];
		435	}
		436
		437	sub password($) {
		438	my $self = shift;
		439	(split /\x00/, $self->[0])[3];
307	}	440	}
308		441
309	=back	442	=back
310		443
311	=cut	444	=cut
312		445
313	reinitialize;
314
315	1;	446	1;
316
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		447
325	=head1 SEE ALSO	448	=head1 SEE ALSO
326		449
327	L<PApp>.	450	L<PApp>.
328		451

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Comparing PApp-SQL/SQL.pm (file contents): Revision 1.5 by root, Sat Jan 6 03:04:03 2001 UTC vs. Revision 1.30 by stefan, Wed Jan 28 19:50:38 2004 UTC

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Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.5 by root, Sat Jan 6 03:04:03 2001 UTC vs.
Revision 1.30 by stefan, Wed Jan 28 19:50:38 2004 UTC