[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 1.18 by root, Mon Dec 31 03:01:49 2001 UTC

…		…
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 "name from 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 = 0.1241;
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 eb 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 and no C<$DBH> is found in the current package. See
		82	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 becessary for your application you can
		117	leave $id empty (i.e. "").
60		118
61	If specified, C<$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	$dbh = connect_cached __FILE__, "DBI:mysql:papp";
		127
		128	Mysql-specific behaviour: The default setting of mysql_client_found_rows
		129	is TRUE, you can overwrite this, though.
69		130
70	=cut	131	=cut
71		132
72	sub connect_cached {	133	sub connect_cached {
73	my ($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	\|\| die "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 $sth = sql_uexec <see sql_exec>
91		159
92	C<sql_exec> is the most important and most-used function in this module.	160	C<sql_exec> is the most important and most-used function in this module.
93		161
94	Runs the given sql command with the given parameters and returns the	162	Runs the given sql command with the given parameters and returns the
95	statement handle. The command and the statement handle will be cached	163	statement handle. The command and the statement handle will be cached
…		…
107	The actual return value from the C<$sth->execute> call is stored in the	175	The actual return value from the C<$sth->execute> call is stored in the
108	package-global (and exported) variable C<$sql_exec>.	176	package-global (and exported) variable C<$sql_exec>.
109		177
110	If any error occurs C<sql_exec> will throw an exception.	178	If any error occurs C<sql_exec> will throw an exception.
111		179
		180	C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
		181	utf8 before calling the C<execute> method.
		182
112	Examples:	183	Examples:
113		184
114	# easy one	185	# easy one
115	my $st = sql_exec "select name, id from table where id = ?", $id;	186	my $st = sql_exec "select name, id from table where id = ?", $id;
116	while (my ($name, $id) = $st->fetchrow_array) { ... };	187	while (my ($name, $id) = $st->fetchrow_array) { ... };
…		…
125	sql_exec $dbh, "update file set name = ?", "oops.txt";	196	sql_exec $dbh, "update file set name = ?", "oops.txt";
126		197
127		198
128	=item sql_fetch <see sql_exec>	199	=item sql_fetch <see sql_exec>
129		200
		201	=item sql_ufetch <see sql_uexec>
		202
130	Execute a sql-statement and fetch the first row of results. Depending on	203	Execute an sql-statement and fetch the first row of results. Depending on
131	the caller context the row will be returned as a list (array context), or	204	the caller context the row will be returned as a list (array context), or
132	just the first columns. In table form:	205	just the first columns. In table form:
133		206
134	CONTEXT RESULT	207	CONTEXT RESULT
135	void ()	208	void ()
…		…
146		219
147	my($name, $amount) = sql_fetch "select ...", args...	220	my($name, $amount) = sql_fetch "select ...", args...
148		221
149	... and it's still quite fast unless you fetch large amounts of data.	222	... and it's still quite fast unless you fetch large amounts of data.
150		223
		224	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		225	utf8 and forces all result values to utf8.
		226
151	=item sql_fetchall <see sql_exec>	227	=item sql_fetchall <see sql_exec>
		228
		229	=item sql_ufetchall <see sql_uexec>
152		230
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	231	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	232	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	233	list context makes sense), but the result still depends on the number of
156	columns in the result:	234	columns in the result:
…		…
168		246
169	for (sql_fetchall "select name, age, place from user") {	247	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	248	my ($name, $age, $place) = @$_;
171	}	249	}
172		250
		251	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		252	values to utf8 and forces all result values to utf8.
		253
173	=item sql_exists "<table> where ...", args...	254	=item sql_exists "<table> where ...", args...
		255
		256	=item sql_uexists <see sql_exists>
174		257
175	Check wether the result of the sql-statement "select xxx from	258	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	259	$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	260	"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	261	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	262	should be quite fast.
		263
		264	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		265	utf8.
180		266
181	Examples:	267	Examples:
182		268
183	print "user 7 exists!\n"	269	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	270	if sql_exists "user where id = ?", 7;
…		…
188		274
189	=cut	275	=cut
190		276
191	=item $lastid = sql_insertid $sth	277	=item $lastid = sql_insertid $sth
192		278
193	Returns the last automatically created key value (e.g. for mysql	279	Returns the last automatically created key value. It must be executed
194	AUTO_INCREMENT or sybase IDENTITY fields). It must be executed directly
195	after executing the insert statement that created it.	280	directly after executing the insert statement that created it. This is
		281	what is actually returned for various databases. If your database is
		282	missing, please send me an e-mail on how to implement this ;)
		283
		284	mysql: first C<AUTO_INCREMENT> column set to NULL
		285	postgres: C<oid> column (is there a way to get the last SERIAL?)
		286	sybase: C<IDENTITY> column of the last insert (slow)
		287	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		288
		289	Except for sybase, this does not require a server access.
196		290
197	=cut	291	=cut
198		292
199	sub sql_insertid($) {	293	sub sql_insertid($) {
200	my $sth = shift or die "sql_insertid requires a statement handle";	294	my $sth = shift or die "sql_insertid requires a statement handle";
201	my $dbh = $sth->{Database};	295	my $dbh = $sth->{Database};
202	my $driver = $dbh->{Driver}{Name};	296	my $driver = $dbh->{Driver}{Name};
203		297
204	$driver eq "mysql" and return $sth->{mysql_insertid};	298	$driver eq "mysql" and return $sth->{mysql_insertid};
		299	$driver eq "Pg" and return $sth->{pg_oid_status};
205	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');	300	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
206	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];	301	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
207		302
208	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";	303	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
209	}	304	}
210		305
…		…
225		320
226	=cut	321	=cut
227		322
228	=item reinitialize [not exported]	323	=item reinitialize [not exported]
229		324
230	Clears any internal caches (statement cache, database handle cache).	325	Clears any internal caches (statement cache, database handle
		326	cache). Should be called after C<fork> and other accidents that invalidate
		327	database handles.
231		328
232	=cut	329	=cut
233		330
234	sub reinitialize {	331	sub reinitialize {
235	cachesize cachesize 0;	332	cachesize cachesize 0;
236	for (values %dbcache) {	333	for (values %dbcache) {
237	eval { $_->disconnect };	334	eval { $_->{InactiveDestroy} = 1 };
238	}	335	}
239	undef %dbcache;	336	undef %dbcache;
240	}	337	}
241		338
242	=back	339	=back
243		340
244	=cut	341	=cut
245		342
		343	reinitialize;
		344
246	package PApp::SQL::Database;	345	package PApp::SQL::Database;
247		346
248	=head2 THE DATABASE CLASS	347	=head2 THE DATABASE CLASS
249		348
250	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	349	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:	350	to serialize on object that contains (or should contain) a database
		351	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.	352	information to recreate the dbh when needed.
253		353
254	The C<PApp::SQL::Database> class does that, in a relatively efficient	354	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	355	fashion: the overhead is currently a single method call per access (you
256	can cache the real dbh if you want).	356	can cache the real dbh if you want).
257		357
…		…
297		397
298	=item $db->dsn	398	=item $db->dsn
299		399
300	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	400	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
301		401
		402	=item $db->login
		403
		404	Return the login name.
		405
		406	=item $db->password
		407
		408	Return the password (emphasizing the fact that the apssword is stored plaintext ;)
		409
302	=cut	410	=cut
303		411
304	sub dsn($) {	412	sub dsn($) {
305	my $self = shift;	413	my $self = shift;
306	$self->[1][1];	414	(split /\x00/, $self->[0])[1];
		415	}
		416
		417	sub login($) {
		418	my $self = shift;
		419	(split /\x00/, $self->[0])[2];
		420	}
		421
		422	sub password($) {
		423	my $self = shift;
		424	(split /\x00/, $self->[0])[3];
307	}	425	}
308		426
309	=back	427	=back
310		428
311	=cut	429	=cut
312		430
313	reinitialize;
314
315	1;	431	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		432
325	=head1 SEE ALSO	433	=head1 SEE ALSO
326		434
327	L<PApp>.	435	L<PApp>.
328		436

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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 1.18 by root, Mon Dec 31 03:01:49 2001 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 1.18 by root, Mon Dec 31 03:01:49 2001 UTC