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Revision 1.10 by root, Mon Feb 5 14:05:08 2001 UTC vs.
Revision 1.34 by root, Mon Jan 9 06:10:40 2006 UTC

1=head1 NAME 1=head1 NAME
2 2
3PApp::SQL - absolutely easy yet fast and powerful sql access 3PApp::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 8
13 my $st = sql_insertid 13 my $st = sql_insertid
14 sql_exec "insert into ... values (?, ?)", $v1, $v2; 14 sql_exec "insert into ... values (?, ?)", $v1, $v2;
15 my $a = sql_fetch "select a from ..."; 15 my $a = sql_fetch "select a from ...";
16 sql_fetch \my($a, $b), "select a,b ..."; 16 sql_fetch \my($a, $b), "select a,b ...";
17 17
18 sql_exists "name from table where name like 'a%'" 18 sql_exists "table where name like 'a%'"
19 or die "a* required but not existent"; 19 or die "a* required but not existent";
20 20
21 my $db = new PApp::SQL::Database "", "DBI:mysql:test", "user", "pass"; 21 my $db = new PApp::SQL::Database "", "DBI:mysql:test", "user", "pass";
22 local $PApp::SQL::DBH = $db->checked_dbh; # does 'ping' 22 local $PApp::SQL::DBH = $db->checked_dbh; # does 'ping'
23 23
27 27
28This module provides you with easy-to-use functions to execute sql 28This module provides you with easy-to-use functions to execute sql
29commands (using DBI). Despite being easy to use, they are also quite 29commands (using DBI). Despite being easy to use, they are also quite
30efficient and allow you to write faster programs in less lines of code. It 30efficient and allow you to write faster programs in less lines of code. It
31should work with anything from perl-5.004_01 onwards, but I only support 31should work with anything from perl-5.004_01 onwards, but I only support
325.005+. 325.005+. UTF8 handling (the C<sql_u*> family of functions) will only be
33effective with perl version 5.006 and beyond.
33 34
34If the descriptions here seem terse or if you always wanted to know 35If the descriptions here seem terse or if you always wanted to know
35what PApp is then have a look at the PApp module which uses this module 36what PApp is then have a look at the PApp module which uses this module
36extensively but also provides you with a lot more gimmicks to play around 37extensively but also provides you with a lot more gimmicks to play around
37with to help you create cool applications ;) 38with to help you create cool applications ;)
43use DBI (); 44use DBI ();
44 45
45BEGIN { 46BEGIN {
46 use base qw(Exporter DynaLoader); 47 use base qw(Exporter DynaLoader);
47 48
48 $VERSION = 0.12; 49 $VERSION = '1.01';
49 @EXPORT = qw( 50 @EXPORT = qw(
50 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
51 ); 53 );
52 @EXPORT_OK = qw( 54 @EXPORT_OK = qw(
53 connect_cached 55 connect_cached
54 ); 56 );
55 57
60our $DBH; # the default database handle 62our $DBH; # the default database handle
61our $Database; # the current SQL::Database object, if applicable 63our $Database; # the current SQL::Database object, if applicable
62 64
63our %dbcache; 65our %dbcache;
64 66
65=head2 GLOBAL VARIABLES 67=head2 Global Variables
66 68
67=over 4 69=over 4
68 70
69=item $sql_exec 71=item $sql_exec
70 72
71Since the C<sql_exec> family of functions return a statement handle there 73Since the C<sql_exec> family of functions return a statement handle there
72must eb another way to test the return value of the C<execute> call. This 74must be another way to test the return value of the C<execute> call. This
73global variable contains the result of the most recent call to C<execute> 75global variable contains the result of the most recent call to C<execute>
74done by this module. 76done by this module.
75 77
76=item $PApp::SQL::DBH 78=item $PApp::SQL::DBH
77 79
78The default database handle used by this module if no C<$DBH> was 80The default database handle used by this module if no C<$DBH> was
79specified as argument and no C<$DBH> is found in the current package. See 81specified as argument. See C<sql_exec> for a discussion.
80C<sql_exec> for a discussion.
81 82
82=item $PApp::SQL::Database 83=item $PApp::SQL::Database
83 84
84The current default C<PApp::SQL::Database>-object. Future versions might 85The current default C<PApp::SQL::Database>-object. Future versions might
85automatically fall back on this database and create database handles from 86automatically fall back on this database and create database handles from
87be nice as a placeholder for the database object that corresponds to 88be nice as a placeholder for the database object that corresponds to
88$PApp::SQL::DBH. 89$PApp::SQL::DBH.
89 90
90=back 91=back
91 92
92=head2 FUNCTIONS 93=head2 Functions
93 94
94=over 4 95=over 4
95 96
96=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect 97=item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect
97 98
109__LINE__ work fine as well). 110__LINE__ work fine as well).
110 111
111The reason C<$id> is necessary is that you might specify special connect 112The reason C<$id> is necessary is that you might specify special connect
112arguments or special flags, or you might want to configure your $DBH 113arguments or special flags, or you might want to configure your $DBH
113differently than maybe other applications requesting the same database 114differently than maybe other applications requesting the same database
114connection. If none of this is becessary for your application you can 115connection. If none of this is necessary for your application you can
115leave $id empty (i.e. ""). 116leave C<$id> empty (i.e. "").
116 117
117If specified, C<$connect> is a callback (e.g. a coderef) that will be 118If specified, C<$connect> is a callback (e.g. a coderef) that will be
118called each time a new connection is being established, with the new 119called each time a new connection is being established, with the new
119C<$dbh> as first argument. 120C<$dbh> as first argument.
120 121
121Examples: 122Examples:
122 123
123 # try your luck opening the papp database without access info 124 # try your luck opening the papp database without access info
124 $dbh = connect_cached __FILE__, "DBI:mysql:papp"; 125 $dbh = connect_cached __FILE__, "DBI:mysql:papp";
126
127Mysql-specific behaviour: The default setting of
128C<mysql_client_found_rows> is TRUE, you can overwrite this, though.
125 129
126=cut 130=cut
127 131
128sub connect_cached { 132sub connect_cached {
129 my ($id, $dsn, $user, $pass, $flags, $connect) = @_; 133 my ($id, $dsn, $user, $pass, $flags, $connect) = @_;
130 # the following line is duplicated in PApp::SQL::Database::new 134 # the following line is duplicated in PApp::SQL::Database::new
131 $id = "$id\0$dsn\0$user\0$pass"; 135 $id = "$id\0$dsn\0$user\0$pass";
132 unless ($dbcache{$id} && $dbcache{$id}->ping) { 136 unless ($dbcache{$id} && $dbcache{$id}->ping) {
133 #warn "connecting to ($dsn|$user|$pass|$flags)\n";#d#
134 # first, nuke our statement cache (sooory ;) 137 # first, nuke our statement cache (sooory ;)
135 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
136 # then connect anew 145 # then connect anew
137 $dbcache{$id} = 146 $dbcache{$id} =
138 eval { DBI->connect($dsn, $user, $pass, $flags) } 147 eval { DBI->connect($dsn, $user, $pass, $flags) }
139 || eval { DBI->connect($dsn, $user, $pass, $flags) } 148 || eval { DBI->connect($dsn, $user, $pass, $flags) }
140 || die "unable to connect to database $dsn: $DBI::errstr\n"; 149 || die "unable to connect to database $dsn: $DBI::errstr\n";
143 $dbcache{$id}; 152 $dbcache{$id};
144} 153}
145 154
146=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] 155=item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...]
147 156
157=item $sth = sql_uexec <see sql_exec>
158
148C<sql_exec> is the most important and most-used function in this module. 159C<sql_exec> is the most important and most-used function in this module.
149 160
150Runs the given sql command with the given parameters and returns the 161Runs the given sql command with the given parameters and returns the
151statement handle. The command and the statement handle will be cached 162statement handle. The command and the statement handle will be cached
152(with the database handle and the sql string as key), so prepare will be 163(with the database handle and the sql string as key), so prepare will be
153called only once for each distinct sql call (please keep in mind that the 164called only once for each distinct sql call (please keep in mind that the
154returned statement will always be the same, so, if you call C<sql_exec> 165returned statement will always be the same, so, if you call C<sql_exec>
155with the same dbh and sql-statement twice (e.g. in a subroutine you 166with the same dbh and sql-statement twice (e.g. in a subroutine you
156called), the statement handle for the first call mustn't be used. 167called), the statement handle for the first call mustn't not be in use
168anymore, as the subsequent call will re-use the handle.
157 169
158The database handle (the first argument) is optional. If it is missing, 170The database handle (the first argument) is optional. If it is missing,
159C<sql_exec> first tries to use the variable C<$DBH> in the current (= 171it tries to use database handle in C<$PApp::SQL::DBH>, which you can set
160calling) package and, if that fails, it tries to use database handle in 172before calling these functions. NOTICE: future and former versions of
161C<$PApp::SQL::DBH>, which you can set before calling these functions. 173PApp::SQL might also look up the global variable C<$DBH> in the callers
174package.
175
176=begin comment
177
178If it is missing, C<sql_exec> first tries to use the variable C<$DBH>
179in the current (= calling) package and, if that fails, it tries to use
180database handle in C<$PApp::SQL::DBH>, which you can set before calling
181these functions.
182
183=end comment
162 184
163The actual return value from the C<$sth->execute> call is stored in the 185The actual return value from the C<$sth->execute> call is stored in the
164package-global (and exported) variable C<$sql_exec>. 186package-global (and exported) variable C<$sql_exec>.
165 187
166If any error occurs C<sql_exec> will throw an exception. 188If any error occurs C<sql_exec> will throw an exception.
189
190C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to
191UTF-8 before calling the C<execute> method.
167 192
168Examples: 193Examples:
169 194
170 # easy one 195 # easy one
171 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;
181 sql_exec $dbh, "update file set name = ?", "oops.txt"; 206 sql_exec $dbh, "update file set name = ?", "oops.txt";
182 207
183 208
184=item sql_fetch <see sql_exec> 209=item sql_fetch <see sql_exec>
185 210
211=item sql_ufetch <see sql_uexec>
212
186Execute a sql-statement and fetch the first row of results. Depending on 213Execute an sql-statement and fetch the first row of results. Depending on
187the caller context the row will be returned as a list (array context), or 214the caller context the row will be returned as a list (array context), or
188just the first columns. In table form: 215just the first columns. In table form:
189 216
190 CONTEXT RESULT 217 CONTEXT RESULT
191 void () 218 void ()
202 229
203 my($name, $amount) = sql_fetch "select ...", args... 230 my($name, $amount) = sql_fetch "select ...", args...
204 231
205... and it's still quite fast unless you fetch large amounts of data. 232... and it's still quite fast unless you fetch large amounts of data.
206 233
234C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
235UTF-8 and forces all result values to UTF-8 (this does I<not> include result
236parameters, only return values. Using bind variables in conjunction with
237sql_u* functions might result in undefined behaviour - we use UTF-8 on
238bind-variables at execution time and it seems to work on DBD::mysql as it
239ignores the UTF-8 bit completely. Which just means that that DBD-driver is
240broken).
241
207=item sql_fetchall <see sql_exec> 242=item sql_fetchall <see sql_exec>
243
244=item sql_ufetchall <see sql_uexec>
208 245
209Similarly to C<sql_fetch>, but all result rows will be fetched (this is 246Similarly to C<sql_fetch>, but all result rows will be fetched (this is
210of course inefficient for large results!). The context is ignored (only 247of course inefficient for large results!). The context is ignored (only
211list context makes sense), but the result still depends on the number of 248list context makes sense), but the result still depends on the number of
212columns in the result: 249columns in the result:
224 261
225 for (sql_fetchall "select name, age, place from user") { 262 for (sql_fetchall "select name, age, place from user") {
226 my ($name, $age, $place) = @$_; 263 my ($name, $age, $place) = @$_;
227 } 264 }
228 265
266C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
267values to UTF-8 and forces all result values to UTF-8 (see the caveats in
268the description of C<sql_ufetch>, though).
269
229=item sql_exists "<table> where ...", args... 270=item sql_exists "<table_references> where <where_condition>...", args...
271
272=item sql_uexists <see sql_exists>
230 273
231Check wether the result of the sql-statement "select xxx from 274Check wether the result of the sql-statement "select xxx from
232$first_argument" would be empty or not (that is, imagine the string 275$first_argument" would be empty or not (that is, imagine the string
233"select from" were prepended to your statement (it isn't)). Should work 276"select * from" were prepended to your statement (it isn't)). Should work
234with every database but can be quite slow, except on mysql, where this 277with every database but can be quite slow, except on mysql, where this
235should be quite fast. 278should be quite fast.
279
280C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
281UTF-8.
236 282
237Examples: 283Examples:
238 284
239 print "user 7 exists!\n" 285 print "user 7 exists!\n"
240 if sql_exists "user where id = ?", 7; 286 if sql_exists "user where id = ?", 7;
253 299
254 mysql: first C<AUTO_INCREMENT> column set to NULL 300 mysql: first C<AUTO_INCREMENT> column set to NULL
255 postgres: C<oid> column (is there a way to get the last SERIAL?) 301 postgres: C<oid> column (is there a way to get the last SERIAL?)
256 sybase: C<IDENTITY> column of the last insert (slow) 302 sybase: C<IDENTITY> column of the last insert (slow)
257 informix: C<SERIAL> or C<SERIAL8> column of the last insert 303 informix: C<SERIAL> or C<SERIAL8> column of the last insert
304 sqlite: C<last_insert_rowid()>
258 305
259Except for sybase, this does not require a server access. 306Except for sybase, this does not require a server access.
260 307
261=cut 308=cut
262 309
267 314
268 $driver eq "mysql" and return $sth->{mysql_insertid}; 315 $driver eq "mysql" and return $sth->{mysql_insertid};
269 $driver eq "Pg" and return $sth->{pg_oid_status}; 316 $driver eq "Pg" and return $sth->{pg_oid_status};
270 $driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY'); 317 $driver eq "Sybase" and return sql_fetch($dbh, 'SELECT @@IDENTITY');
271 $driver eq "Informix" and return $sth->{ix_sqlerrd}[1]; 318 $driver eq "Informix" and return $sth->{ix_sqlerrd}[1];
319 $driver eq "SQLite" and return sql_fetch($dbh, 'SELECT last_insert_rowid ()');
272 320
273 die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid"; 321 die "sql_insertid does not spport the dbd driver '$driver', please see PApp::SQL::sql_insertid";
274} 322}
275 323
276=item [old-size] = cachesize [new-size] 324=item [old-size] = cachesize [new-size]
277 325
278Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The 326Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
279default is somewhere around 50 (= the 50 last recently used statements 327default is somewhere around 50 (= the 50 last recently used statements
280will be cached). It shouldn't be too large, since a simple linear listed 328will be cached). It shouldn't be too large, since a simple linear list
281is used for the cache at the moment (which, for small (<100) cache sizes 329is used for the cache at the moment (which, for small (<100) cache sizes
282is actually quite fast). 330is actually quite fast).
283 331
284The function always returns the cache size in effect I<before> the call, 332The function always returns the cache size in effect I<before> the call,
285so, to nuke the cache (for example, when a database connection has died 333so, to nuke the cache (for example, when a database connection has died
299=cut 347=cut
300 348
301sub reinitialize { 349sub reinitialize {
302 cachesize cachesize 0; 350 cachesize cachesize 0;
303 for (values %dbcache) { 351 for (values %dbcache) {
304 eval { $_->disconnect }; 352 eval { $_->{InactiveDestroy} = 1 };
305 } 353 }
306 undef %dbcache; 354 undef %dbcache;
307} 355}
308 356
309=back 357=back
312 360
313reinitialize; 361reinitialize;
314 362
315package PApp::SQL::Database; 363package PApp::SQL::Database;
316 364
317=head2 THE DATABASE CLASS 365=head2 The Database Class
318 366
319Again (sigh) the problem of persistency. What do you do when you have to serialize on object 367Again (sigh) the problem of persistency. What do you do when you have
320that contains (or should contain) a database handle? Short answer: you don't. Long answer: 368to serialize on object that contains (or should contain) a database
369handle? Short answer: you don't. Long answer: you can embed the necessary
321you can embed the necessary information to recreate the dbh when needed. 370information to recreate the dbh when needed.
322 371
323The C<PApp::SQL::Database> class does that, in a relatively efficient 372The C<PApp::SQL::Database> class does that, in a relatively efficient
324fashion: the overhead is currently a single method call per access (you 373fashion: the overhead is currently a single method call per access (you
325can cache the real dbh if you want). 374can cache the real dbh if you want).
326 375
366 415
367=item $db->dsn 416=item $db->dsn
368 417
369Return the DSN (L<DBI>) fo the database object (e.g. for error messages). 418Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
370 419
420=item $db->login
421
422Return the login name.
423
424=item $db->password
425
426Return the password (emphasizing the fact that the password is stored plaintext ;)
427
371=cut 428=cut
372 429
373sub dsn($) { 430sub dsn($) {
374 my $self = shift; 431 my $self = shift;
375 (split /\x00/, $self->[0])[1]; 432 (split /\x00/, $self->[0])[1];
376} 433}
377 434
435sub login($) {
436 my $self = shift;
437 (split /\x00/, $self->[0])[2];
438}
439
440sub password($) {
441 my $self = shift;
442 (split /\x00/, $self->[0])[3];
443}
444
378=back 445=back
379 446
380=cut 447=cut
381 448
3821; 4491;
385 452
386L<PApp>. 453L<PApp>.
387 454
388=head1 AUTHOR 455=head1 AUTHOR
389 456
390 Marc Lehmann <pcg@goof.com> 457 Marc Lehmann <schmorp@schmorp.de>
391 http://www.goof.com/pcg/marc/ 458 http://home.schmorp.de/
392 459
393=cut 460=cut
394 461

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