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 | |
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 | |
28 | 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 |
29 | 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 |
30 | efficient and allow you to write faster programs in less lines of code. It |
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 |
31 | should work with anything from perl-5.004_01 onwards, but I only support |
32 | 5.005+. |
32 | 5.005+. UTF8 handling (the C<sql_u*> family of functions) will only be |
|
|
33 | effective with perl version 5.006 and beyond. |
33 | |
34 | |
34 | If the descriptions here seem terse or if you always wanted to know |
35 | If the descriptions here seem terse or if you always wanted to know |
35 | what PApp is then have a look at the PApp module which uses this module |
36 | what PApp is then have a look at the PApp module which uses this module |
36 | extensively but also provides you with a lot more gimmicks to play around |
37 | extensively but also provides you with a lot more gimmicks to play around |
37 | with to help you create cool applications ;) |
38 | with to help you create cool applications ;) |
… | |
… | |
43 | use DBI (); |
44 | use DBI (); |
44 | |
45 | |
45 | BEGIN { |
46 | BEGIN { |
46 | use base qw(Exporter DynaLoader); |
47 | use base qw(Exporter DynaLoader); |
47 | |
48 | |
48 | $VERSION = 0.12; |
49 | $VERSION = '1.0'; |
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 | |
… | |
… | |
60 | our $DBH; # the default database handle |
62 | our $DBH; # the default database handle |
61 | our $Database; # the current SQL::Database object, if applicable |
63 | our $Database; # the current SQL::Database object, if applicable |
62 | |
64 | |
63 | our %dbcache; |
65 | our %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 | |
71 | Since the C<sql_exec> family of functions return a statement handle there |
73 | Since the C<sql_exec> family of functions return a statement handle there |
72 | must eb another way to test the return value of the C<execute> call. This |
74 | must be another way to test the return value of the C<execute> call. This |
73 | global variable contains the result of the most recent call to C<execute> |
75 | global variable contains the result of the most recent call to C<execute> |
74 | done by this module. |
76 | done by this module. |
75 | |
77 | |
76 | =item $PApp::SQL::DBH |
78 | =item $PApp::SQL::DBH |
77 | |
79 | |
78 | The default database handle used by this module if no C<$DBH> was |
80 | The default database handle used by this module if no C<$DBH> was |
79 | specified as argument and no C<$DBH> is found in the current package. See |
81 | specified as argument. See C<sql_exec> for a discussion. |
80 | C<sql_exec> for a discussion. |
|
|
81 | |
82 | |
82 | =item $PApp::SQL::Database |
83 | =item $PApp::SQL::Database |
83 | |
84 | |
84 | The current default C<PApp::SQL::Database>-object. Future versions might |
85 | The current default C<PApp::SQL::Database>-object. Future versions might |
85 | automatically fall back on this database and create database handles from |
86 | automatically fall back on this database and create database handles from |
… | |
… | |
87 | be nice as a placeholder for the database object that corresponds to |
88 | be 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, $connect |
97 | |
98 | |
… | |
… | |
109 | __LINE__ work fine as well). |
110 | __LINE__ work fine as well). |
110 | |
111 | |
111 | The reason C<$id> is necessary is that you might specify special connect |
112 | The reason C<$id> is necessary is that you might specify special connect |
112 | arguments or special flags, or you might want to configure your $DBH |
113 | arguments or special flags, or you might want to configure your $DBH |
113 | differently than maybe other applications requesting the same database |
114 | differently than maybe other applications requesting the same database |
114 | connection. If none of this is becessary for your application you can |
115 | connection. If none of this is necessary for your application you can |
115 | leave $id empty (i.e. ""). |
116 | leave C<$id> empty (i.e. ""). |
116 | |
117 | |
117 | 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 |
118 | 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 |
119 | C<$dbh> as first argument. |
120 | C<$dbh> as first argument. |
120 | |
121 | |
121 | Examples: |
122 | Examples: |
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 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
|
|
126 | |
|
|
127 | Mysql-specific behaviour: The default setting of |
|
|
128 | C<mysql_client_found_rows> is TRUE, you can overwrite this, though. |
125 | |
129 | |
126 | =cut |
130 | =cut |
127 | |
131 | |
128 | sub connect_cached { |
132 | sub connect_cached { |
129 | my ($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 $sth = sql_uexec <see sql_exec> |
|
|
158 | |
148 | C<sql_exec> is the most important and most-used function in this module. |
159 | C<sql_exec> is the most important and most-used function in this module. |
149 | |
160 | |
150 | Runs the given sql command with the given parameters and returns the |
161 | Runs the given sql command with the given parameters and returns the |
151 | statement handle. The command and the statement handle will be cached |
162 | statement handle. The command and the statement handle will be cached |
152 | (with the database handle and the sql string as key), so prepare will be |
163 | (with the database handle and the sql string as key), so prepare will be |
153 | called only once for each distinct sql call (please keep in mind that the |
164 | called only once for each distinct sql call (please keep in mind that the |
154 | returned statement will always be the same, so, if you call C<sql_exec> |
165 | returned statement will always be the same, so, if you call C<sql_exec> |
155 | with the same dbh and sql-statement twice (e.g. in a subroutine you |
166 | with the same dbh and sql-statement twice (e.g. in a subroutine you |
156 | called), the statement handle for the first call mustn't be used. |
167 | called), the statement handle for the first call mustn't not be in use |
|
|
168 | anymore, as the subsequent call will re-use the handle. |
157 | |
169 | |
158 | The database handle (the first argument) is optional. If it is missing, |
170 | The database handle (the first argument) is optional. If it is missing, |
159 | C<sql_exec> first tries to use the variable C<$DBH> in the current (= |
171 | it tries to use database handle in C<$PApp::SQL::DBH>, which you can set |
160 | calling) package and, if that fails, it tries to use database handle in |
172 | before calling these functions. NOTICE: future and former versions of |
161 | C<$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<$PApp::SQL::DBH>, which you can set before calling |
|
|
181 | these functions. |
|
|
182 | |
|
|
183 | =end comment |
162 | |
184 | |
163 | The actual return value from the C<$sth->execute> call is stored in the |
185 | The actual return value from the C<$sth->execute> call is stored in the |
164 | package-global (and exported) variable C<$sql_exec>. |
186 | package-global (and exported) variable C<$sql_exec>. |
165 | |
187 | |
166 | 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 | UTF-8 before calling the C<execute> method. |
167 | |
192 | |
168 | Examples: |
193 | Examples: |
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 $dbh, "update file set name = ?", "oops.txt"; |
182 | |
207 | |
183 | |
208 | |
184 | =item sql_fetch <see sql_exec> |
209 | =item sql_fetch <see sql_exec> |
185 | |
210 | |
|
|
211 | =item sql_ufetch <see sql_uexec> |
|
|
212 | |
186 | Execute a sql-statement and fetch the first row of results. Depending on |
213 | Execute an sql-statement and fetch the first row of results. Depending on |
187 | the caller context the row will be returned as a list (array context), or |
214 | the caller context the row will be returned as a list (array context), or |
188 | just the first columns. In table form: |
215 | just the first columns. In table form: |
189 | |
216 | |
190 | CONTEXT RESULT |
217 | CONTEXT RESULT |
191 | void () |
218 | void () |
… | |
… | |
202 | |
229 | |
203 | my($name, $amount) = sql_fetch "select ...", args... |
230 | my($name, $amount) = sql_fetch "select ...", args... |
204 | |
231 | |
205 | ... and it's still quite fast unless you fetch large amounts of data. |
232 | ... and it's still quite fast unless you fetch large amounts of data. |
206 | |
233 | |
|
|
234 | C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to |
|
|
235 | UTF-8 and forces all result values to UTF-8 (this does I<not> include result |
|
|
236 | parameters, only return values. Using bind variables in conjunction with |
|
|
237 | sql_u* functions might result in undefined behaviour - we use UTF-8 on |
|
|
238 | bind-variables at execution time and it seems to work on DBD::mysql as it |
|
|
239 | ignores the UTF-8 bit completely. Which just means that that DBD-driver is |
|
|
240 | broken). |
|
|
241 | |
207 | =item sql_fetchall <see sql_exec> |
242 | =item sql_fetchall <see sql_exec> |
|
|
243 | |
|
|
244 | =item sql_ufetchall <see sql_uexec> |
208 | |
245 | |
209 | Similarly to C<sql_fetch>, but all result rows will be fetched (this is |
246 | Similarly to C<sql_fetch>, but all result rows will be fetched (this is |
210 | of course inefficient for large results!). The context is ignored (only |
247 | of course inefficient for large results!). The context is ignored (only |
211 | list context makes sense), but the result still depends on the number of |
248 | list context makes sense), but the result still depends on the number of |
212 | columns in the result: |
249 | columns in the result: |
… | |
… | |
224 | |
261 | |
225 | for (sql_fetchall "select name, age, place from user") { |
262 | for (sql_fetchall "select name, age, place from user") { |
226 | my ($name, $age, $place) = @$_; |
263 | my ($name, $age, $place) = @$_; |
227 | } |
264 | } |
228 | |
265 | |
|
|
266 | C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input |
|
|
267 | values to UTF-8 and forces all result values to UTF-8 (see the caveats in |
|
|
268 | the 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 | |
231 | Check wether the result of the sql-statement "select xxx from |
274 | Check 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 |
234 | with every database but can be quite slow, except on mysql, where this |
277 | with every database but can be quite slow, except on mysql, where this |
235 | should be quite fast. |
278 | should be quite fast. |
|
|
279 | |
|
|
280 | C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to |
|
|
281 | UTF-8. |
236 | |
282 | |
237 | Examples: |
283 | Examples: |
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; |
… | |
… | |
275 | |
321 | |
276 | =item [old-size] = cachesize [new-size] |
322 | =item [old-size] = cachesize [new-size] |
277 | |
323 | |
278 | Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The |
324 | Returns (and possibly changes) the LRU cache size used by C<sql_exec>. The |
279 | default is somewhere around 50 (= the 50 last recently used statements |
325 | default is somewhere around 50 (= the 50 last recently used statements |
280 | will be cached). It shouldn't be too large, since a simple linear listed |
326 | will be cached). It shouldn't be too large, since a simple linear list |
281 | is used for the cache at the moment (which, for small (<100) cache sizes |
327 | is used for the cache at the moment (which, for small (<100) cache sizes |
282 | is actually quite fast). |
328 | is actually quite fast). |
283 | |
329 | |
284 | The function always returns the cache size in effect I<before> the call, |
330 | The function always returns the cache size in effect I<before> the call, |
285 | so, to nuke the cache (for example, when a database connection has died |
331 | so, to nuke the cache (for example, when a database connection has died |
… | |
… | |
312 | |
358 | |
313 | reinitialize; |
359 | reinitialize; |
314 | |
360 | |
315 | package PApp::SQL::Database; |
361 | package PApp::SQL::Database; |
316 | |
362 | |
317 | =head2 THE DATABASE CLASS |
363 | =head2 The Database Class |
318 | |
364 | |
319 | Again (sigh) the problem of persistency. What do you do when you have to serialize on object |
365 | Again (sigh) the problem of persistency. What do you do when you have |
320 | that contains (or should contain) a database handle? Short answer: you don't. Long answer: |
366 | to serialize on object that contains (or should contain) a database |
|
|
367 | handle? Short answer: you don't. Long answer: you can embed the necessary |
321 | you can embed the necessary information to recreate the dbh when needed. |
368 | information to recreate the dbh when needed. |
322 | |
369 | |
323 | The C<PApp::SQL::Database> class does that, in a relatively efficient |
370 | The C<PApp::SQL::Database> class does that, in a relatively efficient |
324 | fashion: the overhead is currently a single method call per access (you |
371 | fashion: the overhead is currently a single method call per access (you |
325 | can cache the real dbh if you want). |
372 | can cache the real dbh if you want). |
326 | |
373 | |
… | |
… | |
366 | |
413 | |
367 | =item $db->dsn |
414 | =item $db->dsn |
368 | |
415 | |
369 | Return the DSN (L<DBI>) fo the database object (e.g. for error messages). |
416 | Return the DSN (L<DBI>) fo the database object (e.g. for error messages). |
370 | |
417 | |
|
|
418 | =item $db->login |
|
|
419 | |
|
|
420 | Return the login name. |
|
|
421 | |
|
|
422 | =item $db->password |
|
|
423 | |
|
|
424 | Return the password (emphasizing the fact that the password is stored plaintext ;) |
|
|
425 | |
371 | =cut |
426 | =cut |
372 | |
427 | |
373 | sub dsn($) { |
428 | sub dsn($) { |
374 | my $self = shift; |
429 | my $self = shift; |
375 | (split /\x00/, $self->[0])[1]; |
430 | (split /\x00/, $self->[0])[1]; |
376 | } |
431 | } |
377 | |
432 | |
|
|
433 | sub login($) { |
|
|
434 | my $self = shift; |
|
|
435 | (split /\x00/, $self->[0])[2]; |
|
|
436 | } |
|
|
437 | |
|
|
438 | sub password($) { |
|
|
439 | my $self = shift; |
|
|
440 | (split /\x00/, $self->[0])[3]; |
|
|
441 | } |
|
|
442 | |
378 | =back |
443 | =back |
379 | |
444 | |
380 | =cut |
445 | =cut |
381 | |
446 | |
382 | 1; |
447 | 1; |
… | |
… | |
385 | |
450 | |
386 | L<PApp>. |
451 | L<PApp>. |
387 | |
452 | |
388 | =head1 AUTHOR |
453 | =head1 AUTHOR |
389 | |
454 | |
390 | Marc Lehmann <pcg@goof.com> |
455 | Marc Lehmann <schmorp@schmorp.de> |
391 | http://www.goof.com/pcg/marc/ |
456 | http://home.schmorp.de/ |
392 | |
457 | |
393 | =cut |
458 | =cut |
394 | |
459 | |