[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 1.17 by root, Sat Aug 11 02:46:16 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 = 0.1;	49	$VERSION = 0.124;
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<$dbh> as first argument.
64		122
…		…
73	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;	131	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;
74	# the following line is duplicated in PApp::SQL::Database::new	132	# the following line is duplicated in PApp::SQL::Database::new
75	$id = "$id\0$dsn\0$user\0$pass";	133	$id = "$id\0$dsn\0$user\0$pass";
76	unless ($dbcache{$id} && $dbcache{$id}->ping) {	134	unless ($dbcache{$id} && $dbcache{$id}->ping) {
77	#warn "connecting to ($dsn\|$user\|$pass\|$flags)\n";#d#	135	#warn "connecting to ($dsn\|$user\|$pass\|$flags)\n";#d#
78	# first, nuke our cache (sooory ;)	136	# first, nuke our statement cache (sooory ;)
79	cachesize cachesize 0;	137	cachesize cachesize 0;
80	# then connect anew	138	# then connect anew
81	$dbcache{$id} =	139	$dbcache{$id} =
82	eval { DBI->connect($dsn, $user, $pass, $flags) }	140	eval { DBI->connect($dsn, $user, $pass, $flags) }
83	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }	141	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }
84	\|\| die "$DBI::errstr\n";	142	\|\| die "unable to connect to database $dsn: $DBI::errstr\n";
85	$connect->($dbcache{$id}) if $connect;	143	$connect->($dbcache{$id}) if $connect;
86	}	144	}
87	$dbcache{$id};	145	$dbcache{$id};
88	}	146	}
89		147
90	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]	148	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]
		149
		150	=item $sth = sql_uexec <see sql_exec>
91		151
92	C<sql_exec> is the most important and most-used function in this module.	152	C<sql_exec> is the most important and most-used function in this module.
93		153
94	Runs the given sql command with the given parameters and returns the	154	Runs the given sql command with the given parameters and returns the
95	statement handle. The command and the statement handle will be cached	155	statement handle. The command and the statement handle will be cached
…		…
107	The actual return value from the C<$sth->execute> call is stored in the	167	The actual return value from the C<$sth->execute> call is stored in the
108	package-global (and exported) variable C<$sql_exec>.	168	package-global (and exported) variable C<$sql_exec>.
109		169
110	If any error occurs C<sql_exec> will throw an exception.	170	If any error occurs C<sql_exec> will throw an exception.
111		171
		172	C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
		173	utf8 before calling the C<execute> method.
		174
112	Examples:	175	Examples:
113		176
114	# easy one	177	# easy one
115	my $st = sql_exec "select name, id from table where id = ?", $id;	178	my $st = sql_exec "select name, id from table where id = ?", $id;
116	while (my ($name, $id) = $st->fetchrow_array) { ... };	179	while (my ($name, $id) = $st->fetchrow_array) { ... };
…		…
125	sql_exec $dbh, "update file set name = ?", "oops.txt";	188	sql_exec $dbh, "update file set name = ?", "oops.txt";
126		189
127		190
128	=item sql_fetch <see sql_exec>	191	=item sql_fetch <see sql_exec>
129		192
		193	=item sql_ufetch <see sql_uexec>
		194
130	Execute a sql-statement and fetch the first row of results. Depending on	195	Execute an sql-statement and fetch the first row of results. Depending on
131	the caller context the row will be returned as a list (array context), or	196	the caller context the row will be returned as a list (array context), or
132	just the first columns. In table form:	197	just the first columns. In table form:
133		198
134	CONTEXT RESULT	199	CONTEXT RESULT
135	void ()	200	void ()
…		…
146		211
147	my($name, $amount) = sql_fetch "select ...", args...	212	my($name, $amount) = sql_fetch "select ...", args...
148		213
149	... and it's still quite fast unless you fetch large amounts of data.	214	... and it's still quite fast unless you fetch large amounts of data.
150		215
		216	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		217	utf8 and forces all result values to utf8.
		218
151	=item sql_fetchall <see sql_exec>	219	=item sql_fetchall <see sql_exec>
		220
		221	=item sql_ufetchall <see sql_uexec>
152		222
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	223	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	224	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	225	list context makes sense), but the result still depends on the number of
156	columns in the result:	226	columns in the result:
…		…
168		238
169	for (sql_fetchall "select name, age, place from user") {	239	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	240	my ($name, $age, $place) = @$_;
171	}	241	}
172		242
		243	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		244	values to utf8 and forces all result values to utf8.
		245
173	=item sql_exists "<table> where ...", args...	246	=item sql_exists "<table> where ...", args...
		247
		248	=item sql_uexists <see sql_exists>
174		249
175	Check wether the result of the sql-statement "select xxx from	250	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	251	$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	252	"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	253	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	254	should be quite fast.
		255
		256	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		257	utf8.
180		258
181	Examples:	259	Examples:
182		260
183	print "user 7 exists!\n"	261	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	262	if sql_exists "user where id = ?", 7;
…		…
186	die "duplicate key"	264	die "duplicate key"
187	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";	265	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";
188		266
189	=cut	267	=cut
190		268
191	# uncodumented, since unportable (only works with DBH even!). yet it is exported (aaargh!)	269	=item $lastid = sql_insertid $sth
		270
		271	Returns the last automatically created key value. It must be executed
		272	directly after executing the insert statement that created it. This is
		273	what is actually returned for various databases. If your database is
		274	missing, please send me an e-mail on how to implement this ;)
		275
		276	mysql: first C<AUTO_INCREMENT> column set to NULL
		277	postgres: C<oid> column (is there a way to get the last SERIAL?)
		278	sybase: C<IDENTITY> column of the last insert (slow)
		279	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		280
		281	Except for sybase, this does not require a server access.
		282
		283	=cut
		284
192	sub sql_insertid {	285	sub sql_insertid($) {
193	$DBH->{mysql_insertid};	286	my $sth = shift or die "sql_insertid requires a statement handle";
		287	my $dbh = $sth->{Database};
		288	my $driver = $dbh->{Driver}{Name};
		289
		290	$driver eq "mysql" and return $sth->{mysql_insertid};
		291	$driver eq "Pg" and return $sth->{pg_oid_status};
		292	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
		293	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
		294
		295	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
194	}	296	}
195		297
196	=item [old-size] = cachesize [new-size]	298	=item [old-size] = cachesize [new-size]
197		299
198	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	300	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
…		…
210		312
211	=cut	313	=cut
212		314
213	=item reinitialize [not exported]	315	=item reinitialize [not exported]
214		316
215	Clears any internal caches (statement cache, database handle cache).	317	Clears any internal caches (statement cache, database handle
		318	cache). Should be called after C<fork> and other accidents that invalidate
		319	database handles.
216		320
217	=cut	321	=cut
218		322
219	sub reinitialize {	323	sub reinitialize {
220	cachesize cachesize 0;	324	cachesize cachesize 0;
221	for (values %dbcache) {	325	for (values %dbcache) {
222	eval { $_->disconnect };	326	eval { $_->{InactiveDestroy} = 1 };
223	}	327	}
224	undef %dbcache;	328	undef %dbcache;
225	}	329	}
226		330
227	=back	331	=back
228		332
229	=cut	333	=cut
230		334
		335	reinitialize;
		336
231	package PApp::SQL::Database;	337	package PApp::SQL::Database;
232		338
233	=head2 THE DATABASE CLASS	339	=head2 THE DATABASE CLASS
234		340
235	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	341	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:	342	to serialize on object that contains (or should contain) a database
		343	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.	344	information to recreate the dbh when needed.
238		345
239	The C<PApp::SQL::Database> class does that, in a relatively efficient	346	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	347	fashion: the overhead is currently a single method call per access (you
241	can cache the real dbh if you want).	348	can cache the real dbh if you want).
242		349
…		…
282		389
283	=item $db->dsn	390	=item $db->dsn
284		391
285	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	392	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
286		393
		394	=item $db->login
		395
		396	Return the login name.
		397
		398	=item $db->password
		399
		400	Return the password (emphasizing the fact that the apssword is stored plaintext ;)
		401
287	=cut	402	=cut
288		403
289	sub dsn($) {	404	sub dsn($) {
290	my $self = shift;	405	my $self = shift;
291	$self->[1][1];	406	(split /\x00/, $self->[0])[1];
		407	}
		408
		409	sub login($) {
		410	my $self = shift;
		411	(split /\x00/, $self->[0])[2];
		412	}
		413
		414	sub password($) {
		415	my $self = shift;
		416	(split /\x00/, $self->[0])[3];
292	}	417	}
293		418
294	=back	419	=back
295		420
296	=cut	421	=cut
297		422
298	reinitialize;
299
300	1;	423	1;
301
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		424
310	=head1 SEE ALSO	425	=head1 SEE ALSO
311		426
312	L<PApp>.	427	L<PApp>.
313		428

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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 1.17 by root, Sat Aug 11 02:46:16 2001 UTC

Diff Legend

Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.2 by root, Wed Nov 1 03:22:07 2000 UTC vs.
Revision 1.17 by root, Sat Aug 11 02:46:16 2001 UTC