[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 1.28 by root, Sat Nov 2 03:33:49 2002 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 = 0.1;	49	$VERSION = 0.141;
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	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, $amount) = sql_fetch "select ...", args...
148		231
149	... and it's still quite fast unless you fetch large amounts of data.	232	... and it's still quite fast unless you fetch large amounts of data.
150		233
		234	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		235	utf8 and forces all result values to utf8 (this does I<not> include result
		236	parameters, only return values. Using bind variables in cinjunction with
		237	sql_u* functions results in undefined behaviour).
		238
151	=item sql_fetchall <see sql_exec>	239	=item sql_fetchall <see sql_exec>
		240
		241	=item sql_ufetchall <see sql_uexec>
152		242
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	243	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	244	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	245	list context makes sense), but the result still depends on the number of
156	columns in the result:	246	columns in the result:
…		…
168		258
169	for (sql_fetchall "select name, age, place from user") {	259	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	260	my ($name, $age, $place) = @$_;
171	}	261	}
172		262
		263	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		264	values to utf8 and forces all result values to utf8 (see the caveats in
		265	the description of C<sql_ufetch>, though).
		266
173	=item sql_exists "<table> where ...", args...	267	=item sql_exists "<table_references> where <where_condition>...", args...
		268
		269	=item sql_uexists <see sql_exists>
174		270
175	Check wether the result of the sql-statement "select xxx from	271	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	272	$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	273	"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	274	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	275	should be quite fast.
		276
		277	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		278	utf8.
180		279
181	Examples:	280	Examples:
182		281
183	print "user 7 exists!\n"	282	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	283	if sql_exists "user where id = ?", 7;
…		…
186	die "duplicate key"	285	die "duplicate key"
187	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";	286	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";
188		287
189	=cut	288	=cut
190		289
191	# uncodumented, since unportable (only works with DBH even!). yet it is exported (aaargh!)	290	=item $lastid = sql_insertid $sth
		291
		292	Returns the last automatically created key value. It must be executed
		293	directly after executing the insert statement that created it. This is
		294	what is actually returned for various databases. If your database is
		295	missing, please send me an e-mail on how to implement this ;)
		296
		297	mysql: first C<AUTO_INCREMENT> column set to NULL
		298	postgres: C<oid> column (is there a way to get the last SERIAL?)
		299	sybase: C<IDENTITY> column of the last insert (slow)
		300	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		301
		302	Except for sybase, this does not require a server access.
		303
		304	=cut
		305
192	sub sql_insertid {	306	sub sql_insertid($) {
193	$DBH->{mysql_insertid};	307	my $sth = shift or die "sql_insertid requires a statement handle";
		308	my $dbh = $sth->{Database};
		309	my $driver = $dbh->{Driver}{Name};
		310
		311	$driver eq "mysql" and return $sth->{mysql_insertid};
		312	$driver eq "Pg" and return $sth->{pg_oid_status};
		313	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
		314	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
		315
		316	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
194	}	317	}
195		318
196	=item [old-size] = cachesize [new-size]	319	=item [old-size] = cachesize [new-size]
197		320
198	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	321	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
199	default is somewhere around 50 (= the 50 last recently used statements	322	default is somewhere around 50 (= the 50 last recently used statements
200	will be cached). It shouldn't be too large, since a simple linear listed	323	will be cached). It shouldn't be too large, since a simple linear list
201	is used for the cache at the moment (which, for small (<100) cache sizes	324	is used for the cache at the moment (which, for small (<100) cache sizes
202	is actually quite fast).	325	is actually quite fast).
203		326
204	The function always returns the cache size in effect I<before> the call,	327	The function always returns the cache size in effect I<before> the call,
205	so, to nuke the cache (for example, when a database connection has died	328	so, to nuke the cache (for example, when a database connection has died
…		…
210		333
211	=cut	334	=cut
212		335
213	=item reinitialize [not exported]	336	=item reinitialize [not exported]
214		337
215	Clears any internal caches (statement cache, database handle cache).	338	Clears any internal caches (statement cache, database handle
		339	cache). Should be called after C<fork> and other accidents that invalidate
		340	database handles.
216		341
217	=cut	342	=cut
218		343
219	sub reinitialize {	344	sub reinitialize {
220	cachesize cachesize 0;	345	cachesize cachesize 0;
221	for (values %dbcache) {	346	for (values %dbcache) {
222	eval { $_->disconnect };	347	eval { $_->{InactiveDestroy} = 1 };
223	}	348	}
224	undef %dbcache;	349	undef %dbcache;
225	}	350	}
226		351
227	=back	352	=back
228		353
229	=cut	354	=cut
230		355
		356	reinitialize;
		357
231	package PApp::SQL::Database;	358	package PApp::SQL::Database;
232		359
233	=head2 THE DATABASE CLASS	360	=head2 THE DATABASE CLASS
234		361
235	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	362	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:	363	to serialize on object that contains (or should contain) a database
		364	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.	365	information to recreate the dbh when needed.
238		366
239	The C<PApp::SQL::Database> class does that, in a relatively efficient	367	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	368	fashion: the overhead is currently a single method call per access (you
241	can cache the real dbh if you want).	369	can cache the real dbh if you want).
242		370
…		…
282		410
283	=item $db->dsn	411	=item $db->dsn
284		412
285	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	413	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
286		414
		415	=item $db->login
		416
		417	Return the login name.
		418
		419	=item $db->password
		420
		421	Return the password (emphasizing the fact that the password is stored plaintext ;)
		422
287	=cut	423	=cut
288		424
289	sub dsn($) {	425	sub dsn($) {
290	my $self = shift;	426	my $self = shift;
291	$self->[1][1];	427	(split /\x00/, $self->[0])[1];
		428	}
		429
		430	sub login($) {
		431	my $self = shift;
		432	(split /\x00/, $self->[0])[2];
		433	}
		434
		435	sub password($) {
		436	my $self = shift;
		437	(split /\x00/, $self->[0])[3];
292	}	438	}
293		439
294	=back	440	=back
295		441
296	=cut	442	=cut
297		443
298	reinitialize;
299
300	1;	444	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		445
310	=head1 SEE ALSO	446	=head1 SEE ALSO
311		447
312	L<PApp>.	448	L<PApp>.
313		449

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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 1.28 by root, Sat Nov 2 03:33:49 2002 UTC

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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 1.28 by root, Sat Nov 2 03:33:49 2002 UTC