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

Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.8 by root, Mon Jan 22 10:53:36 2001 UTC vs.
Revision 1.40 by root, Mon Feb 13 05:59:55 2012 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 = 0.11;	50	$VERSION = '2.0';
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	}
		61
		62	boot2 DBI::SQL_VARCHAR, DBI::SQL_INTEGER, DBI::SQL_DOUBLE;
40		63
41	our $sql_exec; # last result of sql_exec's execute call	64	our $sql_exec; # last result of sql_exec's execute call
42	our $DBH; # the default database handle	65	our $DBH; # the default database handle
43	our $database; # the current SQL::Database object, if applicable	66	our $Database; # the current SQL::Database object, if applicable
44		67
45	our %dbcache;	68	our %dbcache;
		69
		70	=head2 Global Variables
		71
		72	=over 4
		73
		74	=item $sql_exec
		75
		76	Since the C<sql_exec> family of functions return a statement handle there
		77	must be another way to test the return value of the C<execute> call. This
		78	global variable contains the result of the most recent call to C<execute>
		79	done by this module.
		80
		81	=item $PApp::SQL::DBH
		82
		83	The default database handle used by this module if no C<$DBH> was
		84	specified as argument. See C<sql_exec> for a discussion.
		85
		86	=item $PApp::SQL::Database
		87
		88	The current default C<PApp::SQL::Database>-object. Future versions might
		89	automatically fall back on this database and create database handles from
		90	it if neccessary. At the moment this is not used by this module but might
		91	be nice as a placeholder for the database object that corresponds to
		92	$PApp::SQL::DBH.
		93
		94	=back
		95
		96	=head2 Functions
		97
		98	=over 4
46		99
47	=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect	100	=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect
48		101
49	(not exported by by default)	102	(not exported by by default)
50		103
60	__LINE__ work fine as well).	113	__LINE__ work fine as well).
61		114
62	The reason C<$id> is necessary is that you might specify special connect	115	The reason C<$id> is necessary is that you might specify special connect
63	arguments or special flags, or you might want to configure your $DBH	116	arguments or special flags, or you might want to configure your $DBH
64	differently than maybe other applications requesting the same database	117	differently than maybe other applications requesting the same database
65	connection. If none of this is becessary for your application you can	118	connection. If none of this is necessary for your application you can
66	leave $id empty (i.e. "").	119	leave C<$id> empty (i.e. "").
67		120
68	If specified, C<$connect> is a callback (e.g. a coderef) that will be	121	If specified, C<$connect> is a callback (e.g. a coderef) that will be
69	called each time a new connection is being established, with the new	122	called each time a new connection is being established, with the new
70	C<$dbh> as first argument.	123	C<$dbh> as first argument.
71		124
72	Examples:	125	Examples:
73		126
74	# try your luck opening the papp database without access info	127	# try your luck opening the papp database without access info
75	$dbh = connect_cached __FILE__, "DBI:mysql:papp";	128	$dbh = connect_cached __FILE__, "DBI:mysql:papp";
		129
		130	Mysql-specific behaviour: The default setting of
		131	C<mysql_client_found_rows> is TRUE, you can overwrite this, though.
76		132
77	=cut	133	=cut
78		134
79	sub connect_cached {	135	sub connect_cached {
80	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;	136	my ($id, $dsn, $user, $pass, $flags, $connect) = @_;
81	# the following line is duplicated in PApp::SQL::Database::new	137	# the following line is duplicated in PApp::SQL::Database::new
82	$id = "$id\0$dsn\0$user\0$pass";	138	$id = "$id\0$dsn\0$user\0$pass";
83	unless ($dbcache{$id} && $dbcache{$id}->ping) {	139	unless ($dbcache{$id} && $dbcache{$id}->ping) {
84	#warn "connecting to ($dsn\|$user\|$pass\|$flags)\n";#d#
85	# first, nuke our statement cache (sooory ;)	140	# first, nuke our statement cache (sooory ;)
86	cachesize cachesize 0;	141	cachesize cachesize 0;
		142
		143	# then make mysql behave more standardly by default
		144	$dsn =~ /^[Dd][Bb][Ii]:mysql:/
		145	and $dsn !~ /;mysql_client_found_rows/
		146	and $dsn .= ";mysql_client_found_rows=1";
		147
87	# then connect anew	148	# then connect anew
88	$dbcache{$id} =	149	$dbcache{$id} =
89	eval { DBI->connect($dsn, $user, $pass, $flags) }	150	eval { DBI->connect($dsn, $user, $pass, $flags) }
90	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }	151	\|\| eval { DBI->connect($dsn, $user, $pass, $flags) }
91	\|\| die "unable to connect to database $dsn: $DBI::errstr\n";	152	\|\| Carp::croak "unable to connect to database $dsn: $DBI::errstr\n";
92	$connect->($dbcache{$id}) if $connect;	153	$connect->($dbcache{$id}) if $connect;
93	}	154	}
94	$dbcache{$id};	155	$dbcache{$id};
95	}	156	}
96		157
97	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]	158	=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]
		159
		160	=item $sth = sql_uexec <see sql_exec>
98		161
99	C<sql_exec> is the most important and most-used function in this module.	162	C<sql_exec> is the most important and most-used function in this module.
100		163
101	Runs the given sql command with the given parameters and returns the	164	Runs the given sql command with the given parameters and returns the
102	statement handle. The command and the statement handle will be cached	165	statement handle. The command and the statement handle will be cached
103	(with the database handle and the sql string as key), so prepare will be	166	(with the database handle and the sql string as key), so prepare will be
104	called only once for each distinct sql call (please keep in mind that the	167	called only once for each distinct sql call (please keep in mind that the
105	returned statement will always be the same, so, if you call C<sql_exec>	168	returned statement will always be the same, so, if you call C<sql_exec>
106	with the same dbh and sql-statement twice (e.g. in a subroutine you	169	with the same dbh and sql-statement twice (e.g. in a subroutine you
107	called), the statement handle for the first call mustn't be used.	170	called), the statement handle for the first call mustn't not be in use
		171	anymore, as the subsequent call will re-use the handle.
108		172
109	The database handle (the first argument) is optional. If it is missing,	173	The database handle (the first argument) is optional. If it is missing,
110	C<sql_exec> first tries to use the variable C<$DBH> in the current (=	174	it tries to use database handle in C<$PApp::SQL::DBH>, which you can set
111	calling) package and, if that fails, it tries to use database handle in	175	before calling these functions. NOTICE: future and former versions of
112	C<$PApp::SQL::DBH>, which you can set before calling these functions.	176	PApp::SQL might also look up the global variable C<$DBH> in the callers
		177	package.
		178
		179	=begin comment
		180
		181	If it is missing, C<sql_exec> first tries to use the variable C<$DBH>
		182	in the current (= calling) package and, if that fails, it tries to use
		183	database handle in C<$PApp::SQL::DBH>, which you can set before calling
		184	these functions.
		185
		186	=end comment
113		187
114	The actual return value from the C<$sth->execute> call is stored in the	188	The actual return value from the C<$sth->execute> call is stored in the
115	package-global (and exported) variable C<$sql_exec>.	189	package-global (and exported) variable C<$sql_exec>.
116		190
117	If any error occurs C<sql_exec> will throw an exception.	191	If any error occurs C<sql_exec> will throw an exception.
		192
		193	C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
		194	UTF-8 before calling the C<execute> method.
118		195
119	Examples:	196	Examples:
120		197
121	# easy one	198	# easy one
122	my $st = sql_exec "select name, id from table where id = ?", $id;	199	my $st = sql_exec "select name, id from table where id = ?", $id;
…		…
132	sql_exec $dbh, "update file set name = ?", "oops.txt";	209	sql_exec $dbh, "update file set name = ?", "oops.txt";
133		210
134		211
135	=item sql_fetch <see sql_exec>	212	=item sql_fetch <see sql_exec>
136		213
		214	=item sql_ufetch <see sql_uexec>
		215
137	Execute a sql-statement and fetch the first row of results. Depending on	216	Execute an sql-statement and fetch the first row of results. Depending on
138	the caller context the row will be returned as a list (array context), or	217	the caller context the row will be returned as a list (array context), or
139	just the first columns. In table form:	218	just the first columns. In table form:
140		219
141	CONTEXT RESULT	220	CONTEXT RESULT
142	void ()	221	void ()
…		…
153		232
154	my($name, $amount) = sql_fetch "select ...", args...	233	my($name, $amount) = sql_fetch "select ...", args...
155		234
156	... and it's still quite fast unless you fetch large amounts of data.	235	... and it's still quite fast unless you fetch large amounts of data.
157		236
		237	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		238	UTF-8 and forces all result values to UTF-8 (this does I<not> include result
		239	parameters, only return values. Using bind variables in conjunction with
		240	sql_u* functions might result in undefined behaviour - we use UTF-8 on
		241	bind-variables at execution time and it seems to work on DBD::mysql as it
		242	ignores the UTF-8 bit completely. Which just means that that DBD-driver is
		243	broken).
		244
158	=item sql_fetchall <see sql_exec>	245	=item sql_fetchall <see sql_exec>
		246
		247	=item sql_ufetchall <see sql_uexec>
159		248
160	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	249	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
161	of course inefficient for large results!). The context is ignored (only	250	of course inefficient for large results!). The context is ignored (only
162	list context makes sense), but the result still depends on the number of	251	list context makes sense), but the result still depends on the number of
163	columns in the result:	252	columns in the result:
…		…
175		264
176	for (sql_fetchall "select name, age, place from user") {	265	for (sql_fetchall "select name, age, place from user") {
177	my ($name, $age, $place) = @$_;	266	my ($name, $age, $place) = @$_;
178	}	267	}
179		268
		269	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		270	values to UTF-8 and forces all result values to UTF-8 (see the caveats in
		271	the description of C<sql_ufetch>, though).
		272
180	=item sql_exists "<table> where ...", args...	273	=item sql_exists "<table_references> where <where_condition>...", args...
		274
		275	=item sql_uexists <see sql_exists>
181		276
182	Check wether the result of the sql-statement "select xxx from	277	Check wether the result of the sql-statement "select xxx from
183	$first_argument" would be empty or not (that is, imagine the string	278	$first_argument" would be empty or not (that is, imagine the string
184	"select from" were prepended to your statement (it isn't)). Should work	279	"select * from" were prepended to your statement (it isn't)). Should work
185	with every database but can be quite slow, except on mysql, where this	280	with every database but can be quite slow, except on mysql, where this
186	should be quite fast.	281	should be quite fast.
		282
		283	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		284	UTF-8.
187		285
188	Examples:	286	Examples:
189		287
190	print "user 7 exists!\n"	288	print "user 7 exists!\n"
191	if sql_exists "user where id = ?", 7;	289	if sql_exists "user where id = ?", 7;
…		…
204		302
205	mysql: first C<AUTO_INCREMENT> column set to NULL	303	mysql: first C<AUTO_INCREMENT> column set to NULL
206	postgres: C<oid> column (is there a way to get the last SERIAL?)	304	postgres: C<oid> column (is there a way to get the last SERIAL?)
207	sybase: C<IDENTITY> column of the last insert (slow)	305	sybase: C<IDENTITY> column of the last insert (slow)
208	informix: C<SERIAL> or C<SERIAL8> column of the last insert	306	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		307	sqlite: C<last_insert_rowid()>
209		308
210	Except for sybase, this does not require a server access.	309	Except for sybase, this does not require a server access.
211		310
212	=cut	311	=cut
213		312
214	sub sql_insertid($) {	313	sub sql_insertid($) {
215	my $sth = shift or die "sql_insertid requires a statement handle";	314	my $sth = shift or Carp::croak "sql_insertid requires a statement handle";
216	my $dbh = $sth->{Database};	315	my $dbh = $sth->{Database};
217	my $driver = $dbh->{Driver}{Name};	316	my $driver = $dbh->{Driver}{Name};
218		317
219	$driver eq "mysql" and return $sth->{mysql_insertid};	318	$driver eq "mysql" and return $sth->{mysql_insertid};
220	$driver eq "Pg" and return $sth->{pg_oid_status};	319	$driver eq "Pg" and return $sth->{pg_oid_status};
221	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');	320	$driver eq "Sybase" and return sql_fetch ($dbh, 'SELECT @@IDENTITY');
222	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];	321	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
		322	$driver eq "SQLite" and return sql_fetch ($dbh, 'SELECT last_insert_rowid ()');
223		323
224	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";	324	Carp::croak "sql_insertid does not support the dbd driver '$driver', at";
225	}	325	}
226		326
227	=item [old-size] = cachesize [new-size]	327	=item [old-size] = cachesize [new-size]
228		328
229	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	329	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
230	default is somewhere around 50 (= the 50 last recently used statements	330	default is somewhere around 50 (= the 50 last recently used statements
231	will be cached). It shouldn't be too large, since a simple linear listed	331	will be cached). It shouldn't be too large, since a simple linear list
232	is used for the cache at the moment (which, for small (<100) cache sizes	332	is used for the cache at the moment (which, for small (<100) cache sizes
233	is actually quite fast).	333	is actually quite fast).
234		334
235	The function always returns the cache size in effect I<before> the call,	335	The function always returns the cache size in effect I<before> the call,
236	so, to nuke the cache (for example, when a database connection has died	336	so, to nuke the cache (for example, when a database connection has died
…		…
241		341
242	=cut	342	=cut
243		343
244	=item reinitialize [not exported]	344	=item reinitialize [not exported]
245		345
246	Clears any internal caches (statement cache, database handle cache).	346	Clears any internal caches (statement cache, database handle
		347	cache). Should be called after C<fork> and other accidents that invalidate
		348	database handles.
247		349
248	=cut	350	=cut
249		351
250	sub reinitialize {	352	sub reinitialize {
251	cachesize cachesize 0;	353	cachesize cachesize 0;
252	for (values %dbcache) {	354	for (values %dbcache) {
253	eval { $_->disconnect };	355	eval { $_->{InactiveDestroy} = 1 };
254	}	356	}
255	undef %dbcache;	357	undef %dbcache;
256	}	358	}
257		359
258	=back	360	=back
259		361
260	=cut	362	=cut
261		363
262	reinitialize;	364	reinitialize;
263		365
		366	=head2 Type Deduction
		367
		368	Since every database driver seems to deduce parameter types differently,
		369	usually wrongly, and at leats in the case of DBD::mysql, different in
		370	every other release or so, and this can and does lead to data corruption,
		371	this module does type deduction itself.
		372
		373	What does it mean? Simple - sql parameters for placeholders will be
		374	explicitly marked as SQL_VARCHAR, SQL_INTEGER or SQL_DOUBLE the first time
		375	a statement is prepared.
		376
		377	To force a specific type, you can either continue to use e.g. sql casts,
		378	or you can make sure to consistently use strings or numbers. To make a
		379	perl scalar look enough like a string or a number, use this when passing
		380	it to sql_exec or a similar functions:
		381
		382	"$string" # to pass a string
		383	$num+0 # to pass a number
		384
		385	=cut
		386
264	package PApp::SQL::Database;	387	package PApp::SQL::Database;
265		388
266	=head2 THE DATABASE CLASS	389	=head2 The Database Class
267		390
268	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	391	Again (sigh) the problem of persistency. What do you do when you have
269	that contains (or should contain) a database handle? Short answer: you don't. Long answer:	392	to serialize on object that contains (or should contain) a database
		393	handle? Short answer: you don't. Long answer: you can embed the necessary
270	you can embed the necessary information to recreate the dbh when needed.	394	information to recreate the dbh when needed.
271		395
272	The C<PApp::SQL::Database> class does that, in a relatively efficient	396	The C<PApp::SQL::Database> class does that, in a relatively efficient
273	fashion: the overhead is currently a single method call per access (you	397	fashion: the overhead is currently a single method call per access (you
274	can cache the real dbh if you want).	398	can cache the real dbh if you want).
275		399
…		…
308		432
309	sub checked_dbh($) {	433	sub checked_dbh($) {
310	my $dbh = $dbcache{$_[0][0]};	434	my $dbh = $dbcache{$_[0][0]};
311	$dbh && $dbh->ping	435	$dbh && $dbh->ping
312	? $dbh	436	? $dbh
313	: PApp::SQL::connect_cached((split /\x00/, $_[0][0]), $_[0][1], $_[0][2]);	437	: PApp::SQL::connect_cached((split /\x00/, $_[0][0], 4), $_[0][1], $_[0][2]);
314	}	438	}
315		439
316	=item $db->dsn	440	=item $db->dsn
317		441
318	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	442	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
		443
		444	=item $db->login
		445
		446	Return the login name.
		447
		448	=item $db->password
		449
		450	Return the password (emphasizing the fact that the password is stored plaintext ;)
319		451
320	=cut	452	=cut
321		453
322	sub dsn($) {	454	sub dsn($) {
323	my $self = shift;	455	my $self = shift;
324	$self->[1][1];	456	(split /\x00/, $self->[0])[1];
		457	}
		458
		459	sub login($) {
		460	my $self = shift;
		461	(split /\x00/, $self->[0])[2];
		462	}
		463
		464	sub password($) {
		465	my $self = shift;
		466	(split /\x00/, $self->[0])[3];
325	}	467	}
326		468
327	=back	469	=back
328		470
329	=cut	471	=cut
330		472
331	1;	473	1;
332		474
333	=head1 BUGS
334
335	As of this writing, sql_fetch and sql_fetchall are not very well tested
336	(they were just re-written in C).
337
338	sql_exists could be faster (it is written very ugly to not change the
339	current package).
340
341	=head1 SEE ALSO	475	=head1 SEE ALSO
342		476
343	L<PApp>.	477	L<PApp>.
344		478
345	=head1 AUTHOR	479	=head1 AUTHOR
346		480
347	Marc Lehmann <pcg@goof.com>	481	Marc Lehmann <schmorp@schmorp.de>
348	http://www.goof.com/pcg/marc/	482	http://home.schmorp.de/
349		483
350	=cut	484	=cut
351		485

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Comparing PApp-SQL/SQL.pm (file contents): Revision 1.8 by root, Mon Jan 22 10:53:36 2001 UTC vs. Revision 1.40 by root, Mon Feb 13 05:59:55 2012 UTC

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Comparing PApp-SQL/SQL.pm (file contents):
Revision 1.8 by root, Mon Jan 22 10:53:36 2001 UTC vs.
Revision 1.40 by root, Mon Feb 13 05:59:55 2012 UTC