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Revision 1.10 by root, Mon Feb 5 14:05:08 2001 UTC vs.
Revision 1.26 by root, Tue Apr 16 17:18:37 2002 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 = 0.131;
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
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 $PApp::SQL::Database
83 84
84The current default C<PApp::SQL::Database>-object. Future versions might 85The current default C<PApp::SQL::Database>-object. Future versions might
85automatically fall back on this database and create database handles from 86automatically fall back on this database and create database handles from
109__LINE__ work fine as well). 110__LINE__ work fine as well).
110 111
111The reason C<$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
191utf8 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, $amount) = sql_fetch "select ...", args...
204 231
205... and it's still quite fast unless you fetch large amounts of data. 232... and it's still quite fast unless you fetch large amounts of data.
206 233
234C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to
235utf8 and forces all result values to utf8 (this does I<not> include result
236parameters, only return values. Using bind variables in cinjunction with
237sql_u* functions results in undefined behaviour).
238
207=item sql_fetchall <see sql_exec> 239=item sql_fetchall <see sql_exec>
240
241=item sql_ufetchall <see sql_uexec>
208 242
209Similarly to C<sql_fetch>, but all result rows will be fetched (this is 243Similarly to C<sql_fetch>, but all result rows will be fetched (this is
210of course inefficient for large results!). The context is ignored (only 244of course inefficient for large results!). The context is ignored (only
211list context makes sense), but the result still depends on the number of 245list context makes sense), but the result still depends on the number of
212columns in the result: 246columns in the result:
224 258
225 for (sql_fetchall "select name, age, place from user") { 259 for (sql_fetchall "select name, age, place from user") {
226 my ($name, $age, $place) = @$_; 260 my ($name, $age, $place) = @$_;
227 } 261 }
228 262
263C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input
264values to utf8 and forces all result values to utf8 (see the caveats in
265the description of C<sql_ufetch>, though).
266
229=item sql_exists "<table> where ...", args... 267=item sql_exists "<table_references> where <where_condition>...", args...
268
269=item sql_uexists <see sql_exists>
230 270
231Check wether the result of the sql-statement "select xxx from 271Check wether the result of the sql-statement "select xxx from
232$first_argument" would be empty or not (that is, imagine the string 272$first_argument" would be empty or not (that is, imagine the string
233"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
234with every database but can be quite slow, except on mysql, where this 274with every database but can be quite slow, except on mysql, where this
235should be quite fast. 275should be quite fast.
276
277C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to
278utf8.
236 279
237Examples: 280Examples:
238 281
239 print "user 7 exists!\n" 282 print "user 7 exists!\n"
240 if sql_exists "user where id = ?", 7; 283 if sql_exists "user where id = ?", 7;
275 318
276=item [old-size] = cachesize [new-size] 319=item [old-size] = cachesize [new-size]
277 320
278Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The 321Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The
279default is somewhere around 50 (= the 50 last recently used statements 322default is somewhere around 50 (= the 50 last recently used statements
280will be cached). It shouldn't be too large, since a simple linear listed 323will 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 324is used for the cache at the moment (which, for small (<100) cache sizes
282is actually quite fast). 325is actually quite fast).
283 326
284The function always returns the cache size in effect I<before> the call, 327The 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 328so, to nuke the cache (for example, when a database connection has died
299=cut 342=cut
300 343
301sub reinitialize { 344sub reinitialize {
302 cachesize cachesize 0; 345 cachesize cachesize 0;
303 for (values %dbcache) { 346 for (values %dbcache) {
304 eval { $_->disconnect }; 347 eval { $_->{InactiveDestroy} = 1 };
305 } 348 }
306 undef %dbcache; 349 undef %dbcache;
307} 350}
308 351
309=back 352=back
314 357
315package PApp::SQL::Database; 358package PApp::SQL::Database;
316 359
317=head2 THE DATABASE CLASS 360=head2 THE DATABASE CLASS
318 361
319Again (sigh) the problem of persistency. What do you do when you have to serialize on object 362Again (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: 363to serialize on object that contains (or should contain) a database
364handle? Short answer: you don't. Long answer: you can embed the necessary
321you can embed the necessary information to recreate the dbh when needed. 365information to recreate the dbh when needed.
322 366
323The C<PApp::SQL::Database> class does that, in a relatively efficient 367The C<PApp::SQL::Database> class does that, in a relatively efficient
324fashion: the overhead is currently a single method call per access (you 368fashion: the overhead is currently a single method call per access (you
325can cache the real dbh if you want). 369can cache the real dbh if you want).
326 370
366 410
367=item $db->dsn 411=item $db->dsn
368 412
369Return the DSN (L<DBI>) fo the database object (e.g. for error messages). 413Return the DSN (L<DBI>) fo the database object (e.g. for error messages).
370 414
415=item $db->login
416
417Return the login name.
418
419=item $db->password
420
421Return the password (emphasizing the fact that the password is stored plaintext ;)
422
371=cut 423=cut
372 424
373sub dsn($) { 425sub dsn($) {
374 my $self = shift; 426 my $self = shift;
375 (split /\x00/, $self->[0])[1]; 427 (split /\x00/, $self->[0])[1];
376} 428}
377 429
430sub login($) {
431 my $self = shift;
432 (split /\x00/, $self->[0])[2];
433}
434
435sub password($) {
436 my $self = shift;
437 (split /\x00/, $self->[0])[3];
438}
439
378=back 440=back
379 441
380=cut 442=cut
381 443
3821; 4441;

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