[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 1.23 by root, Sun Apr 7 16:23:56 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 = 0.13;
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 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 $DBH
		115	differently than maybe other applications requesting the same database
		116	connection. If none of this is necessary for your application you can
		117	leave C<$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	$dbh = connect_cached __FILE__, "DBI:mysql:papp";
		127
		128	Mysql-specific behaviour: The default setting of
		129	C<mysql_client_found_rows> is TRUE, you can overwrite this, though.
69		130
70	=cut	131	=cut
71		132
72	sub connect_cached {	133	sub connect_cached {
73	my ($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 $sth = sql_uexec <see sql_exec>
91		159
92	C<sql_exec> is the most important and most-used function in this module.	160	C<sql_exec> is the most important and most-used function in this module.
93		161
94	Runs the given sql command with the given parameters and returns the	162	Runs the given sql command with the given parameters and returns the
95	statement handle. The command and the statement handle will be cached	163	statement handle. The command and the statement handle will be cached
96	(with the database handle and the sql string as key), so prepare will be	164	(with the database handle and the sql string as key), so prepare will be
97	called only once for each distinct sql call (please keep in mind that the	165	called only once for each distinct sql call (please keep in mind that the
98	returned statement will always be the same, so, if you call C<sql_exec>	166	returned statement will always be the same, so, if you call C<sql_exec>
99	with the same dbh and sql-statement twice (e.g. in a subroutine you	167	with the same dbh and sql-statement twice (e.g. in a subroutine you
100	called), the statement handle for the first call mustn't be used.	168	called), the statement handle for the first call mustn't not be in use
		169	anymore, as the subsequent call will re-use the handle.
101		170
102	The database handle (the first argument) is optional. If it is missing,	171	The database handle (the first argument) is optional. If it is missing,
103	C<sql_exec> first tries to use the variable C<$DBH> in the current (=	172	C<sql_exec> first tries to use the variable C<$DBH> in the current (=
104	calling) package and, if that fails, it tries to use database handle in	173	calling) package and, if that fails, it tries to use database handle in
105	C<$PApp::SQL::DBH>, which you can set before calling these functions.	174	C<$PApp::SQL::DBH>, which you can set before calling these functions.
106		175
107	The actual return value from the C<$sth->execute> call is stored in the	176	The actual return value from the C<$sth->execute> call is stored in the
108	package-global (and exported) variable C<$sql_exec>.	177	package-global (and exported) variable C<$sql_exec>.
109		178
110	If any error occurs C<sql_exec> will throw an exception.	179	If any error occurs C<sql_exec> will throw an exception.
		180
		181	C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
		182	utf8 before calling the C<execute> method.
111		183
112	Examples:	184	Examples:
113		185
114	# easy one	186	# easy one
115	my $st = sql_exec "select name, id from table where id = ?", $id;	187	my $st = sql_exec "select name, id from table where id = ?", $id;
125	sql_exec $dbh, "update file set name = ?", "oops.txt";	197	sql_exec $dbh, "update file set name = ?", "oops.txt";
126		198
127		199
128	=item sql_fetch <see sql_exec>	200	=item sql_fetch <see sql_exec>
129		201
		202	=item sql_ufetch <see sql_uexec>
		203
130	Execute a sql-statement and fetch the first row of results. Depending on	204	Execute an sql-statement and fetch the first row of results. Depending on
131	the caller context the row will be returned as a list (array context), or	205	the caller context the row will be returned as a list (array context), or
132	just the first columns. In table form:	206	just the first columns. In table form:
133		207
134	CONTEXT RESULT	208	CONTEXT RESULT
135	void ()	209	void ()
…		…
146		220
147	my($name, $amount) = sql_fetch "select ...", args...	221	my($name, $amount) = sql_fetch "select ...", args...
148		222
149	... and it's still quite fast unless you fetch large amounts of data.	223	... and it's still quite fast unless you fetch large amounts of data.
150		224
		225	C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
		226	utf8 and forces all result values to utf8 (this does I<not> include result
		227	parameters, only return values. Using bind variables in cinjunction with
		228	sql_u* functions results in undefined behaviour).
		229
151	=item sql_fetchall <see sql_exec>	230	=item sql_fetchall <see sql_exec>
		231
		232	=item sql_ufetchall <see sql_uexec>
152		233
153	Similarly to C<sql_fetch>, but all result rows will be fetched (this is	234	Similarly to C<sql_fetch>, but all result rows will be fetched (this is
154	of course inefficient for large results!). The context is ignored (only	235	of course inefficient for large results!). The context is ignored (only
155	list context makes sense), but the result still depends on the number of	236	list context makes sense), but the result still depends on the number of
156	columns in the result:	237	columns in the result:
…		…
168		249
169	for (sql_fetchall "select name, age, place from user") {	250	for (sql_fetchall "select name, age, place from user") {
170	my ($name, $age, $place) = @$_;	251	my ($name, $age, $place) = @$_;
171	}	252	}
172		253
		254	C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
		255	values to utf8 and forces all result values to utf8 (see the caveats in
		256	the description of C<sql_ufetch>, though).
		257
173	=item sql_exists "<table> where ...", args...	258	=item sql_exists "<table_references> where <where_condition>...", args...
		259
		260	=item sql_uexists <see sql_exists>
174		261
175	Check wether the result of the sql-statement "select xxx from	262	Check wether the result of the sql-statement "select xxx from
176	$first_argument" would be empty or not (that is, imagine the string	263	$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	264	"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	265	with every database but can be quite slow, except on mysql, where this
179	should be quite fast.	266	should be quite fast.
		267
		268	C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
		269	utf8.
180		270
181	Examples:	271	Examples:
182		272
183	print "user 7 exists!\n"	273	print "user 7 exists!\n"
184	if sql_exists "user where id = ?", 7;	274	if sql_exists "user where id = ?", 7;
…		…
186	die "duplicate key"	276	die "duplicate key"
187	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";	277	if sql_exists "user where name = ? and pass = ?", "stefan", "geheim";
188		278
189	=cut	279	=cut
190		280
191	# uncodumented, since unportable (only works with DBH even!). yet it is exported (aaargh!)	281	=item $lastid = sql_insertid $sth
		282
		283	Returns the last automatically created key value. It must be executed
		284	directly after executing the insert statement that created it. This is
		285	what is actually returned for various databases. If your database is
		286	missing, please send me an e-mail on how to implement this ;)
		287
		288	mysql: first C<AUTO_INCREMENT> column set to NULL
		289	postgres: C<oid> column (is there a way to get the last SERIAL?)
		290	sybase: C<IDENTITY> column of the last insert (slow)
		291	informix: C<SERIAL> or C<SERIAL8> column of the last insert
		292
		293	Except for sybase, this does not require a server access.
		294
		295	=cut
		296
192	sub sql_insertid {	297	sub sql_insertid($) {
193	$DBH->{mysql_insertid};	298	my $sth = shift or die "sql_insertid requires a statement handle";
		299	my $dbh = $sth->{Database};
		300	my $driver = $dbh->{Driver}{Name};
		301
		302	$driver eq "mysql" and return $sth->{mysql_insertid};
		303	$driver eq "Pg" and return $sth->{pg_oid_status};
		304	$driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
		305	$driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
		306
		307	die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
194	}	308	}
195		309
196	=item [old-size] = cachesize [new-size]	310	=item [old-size] = cachesize [new-size]
197		311
198	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The	312	Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
…		…
210		324
211	=cut	325	=cut
212		326
213	=item reinitialize [not exported]	327	=item reinitialize [not exported]
214		328
215	Clears any internal caches (statement cache, database handle cache).	329	Clears any internal caches (statement cache, database handle
		330	cache). Should be called after C<fork> and other accidents that invalidate
		331	database handles.
216		332
217	=cut	333	=cut
218		334
219	sub reinitialize {	335	sub reinitialize {
220	cachesize cachesize 0;	336	cachesize cachesize 0;
221	for (values %dbcache) {	337	for (values %dbcache) {
222	eval { $_->disconnect };	338	eval { $_->{InactiveDestroy} = 1 };
223	}	339	}
224	undef %dbcache;	340	undef %dbcache;
225	}	341	}
226		342
227	=back	343	=back
228		344
229	=cut	345	=cut
230		346
		347	reinitialize;
		348
231	package PApp::SQL::Database;	349	package PApp::SQL::Database;
232		350
233	=head2 THE DATABASE CLASS	351	=head2 THE DATABASE CLASS
234		352
235	Again (sigh) the problem of persistency. What do you do when you have to serialize on object	353	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:	354	to serialize on object that contains (or should contain) a database
		355	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.	356	information to recreate the dbh when needed.
238		357
239	The C<PApp::SQL::Database> class does that, in a relatively efficient	358	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	359	fashion: the overhead is currently a single method call per access (you
241	can cache the real dbh if you want).	360	can cache the real dbh if you want).
242		361
…		…
282		401
283	=item $db->dsn	402	=item $db->dsn
284		403
285	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).	404	Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
286		405
		406	=item $db->login
		407
		408	Return the login name.
		409
		410	=item $db->password
		411
		412	Return the password (emphasizing the fact that the apssword is stored plaintext ;)
		413
287	=cut	414	=cut
288		415
289	sub dsn($) {	416	sub dsn($) {
290	my $self = shift;	417	my $self = shift;
291	$self->[1][1];	418	(split /\x00/, $self->[0])[1];
		419	}
		420
		421	sub login($) {
		422	my $self = shift;
		423	(split /\x00/, $self->[0])[2];
		424	}
		425
		426	sub password($) {
		427	my $self = shift;
		428	(split /\x00/, $self->[0])[3];
292	}	429	}
293		430
294	=back	431	=back
295		432
296	=cut	433	=cut
297		434
298	reinitialize;
299
300	1;	435	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		436
310	=head1 SEE ALSO	437	=head1 SEE ALSO
311		438
312	L<PApp>.	439	L<PApp>.
313		440

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing PApp-SQL/SQL.pm (file contents): Revision 1.2 by root, Wed Nov 1 03:22:07 2000 UTC vs. Revision 1.23 by root, Sun Apr 7 16:23:56 2002 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 1.23 by root, Sun Apr 7 16:23:56 2002 UTC