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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 |
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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 ;) |
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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 = 0.122; |
49 | $VERSION = 0.1241; |
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 |
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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 | |
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121 | Examples: |
123 | Examples: |
122 | |
124 | |
123 | # try your luck opening the papp database without access info |
125 | # try your luck opening the papp database without access info |
124 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
126 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
125 | |
127 | |
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128 | Mysql-specific behaviour: The default setting of mysql_client_found_rows |
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129 | is TRUE, you can overwrite this, though. |
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130 | |
126 | =cut |
131 | =cut |
127 | |
132 | |
128 | sub connect_cached { |
133 | sub connect_cached { |
129 | my ($id, $dsn, $user, $pass, $flags, $connect) = @_; |
134 | my ($id, $dsn, $user, $pass, $flags, $connect) = @_; |
130 | # the following line is duplicated in PApp::SQL::Database::new |
135 | # the following line is duplicated in PApp::SQL::Database::new |
131 | $id = "$id\0$dsn\0$user\0$pass"; |
136 | $id = "$id\0$dsn\0$user\0$pass"; |
132 | unless ($dbcache{$id} && $dbcache{$id}->ping) { |
137 | unless ($dbcache{$id} && $dbcache{$id}->ping) { |
133 | #warn "connecting to ($dsn|$user|$pass|$flags)\n";#d# |
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134 | # first, nuke our statement cache (sooory ;) |
138 | # first, nuke our statement cache (sooory ;) |
135 | cachesize cachesize 0; |
139 | cachesize cachesize 0; |
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140 | |
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141 | # then make mysql behave more standardly by default |
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142 | $dsn =~ /^[Dd][Bb][Ii]:mysql:/ |
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143 | and $dsn !~ /;mysql_client_found_rows/ |
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144 | and $dsn .= ";mysql_client_found_rows=1"; |
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145 | |
136 | # then connect anew |
146 | # then connect anew |
137 | $dbcache{$id} = |
147 | $dbcache{$id} = |
138 | eval { DBI->connect($dsn, $user, $pass, $flags) } |
148 | eval { DBI->connect($dsn, $user, $pass, $flags) } |
139 | || eval { DBI->connect($dsn, $user, $pass, $flags) } |
149 | || eval { DBI->connect($dsn, $user, $pass, $flags) } |
140 | || die "unable to connect to database $dsn: $DBI::errstr\n"; |
150 | || die "unable to connect to database $dsn: $DBI::errstr\n"; |
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143 | $dbcache{$id}; |
153 | $dbcache{$id}; |
144 | } |
154 | } |
145 | |
155 | |
146 | =item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] |
156 | =item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] |
147 | |
157 | |
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158 | =item $sth = sql_uexec <see sql_exec> |
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159 | |
148 | C<sql_exec> is the most important and most-used function in this module. |
160 | C<sql_exec> is the most important and most-used function in this module. |
149 | |
161 | |
150 | Runs the given sql command with the given parameters and returns the |
162 | Runs the given sql command with the given parameters and returns the |
151 | statement handle. The command and the statement handle will be cached |
163 | statement handle. The command and the statement handle will be cached |
152 | (with the database handle and the sql string as key), so prepare will be |
164 | (with the database handle and the sql string as key), so prepare will be |
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163 | The actual return value from the C<$sth->execute> call is stored in the |
175 | The actual return value from the C<$sth->execute> call is stored in the |
164 | package-global (and exported) variable C<$sql_exec>. |
176 | package-global (and exported) variable C<$sql_exec>. |
165 | |
177 | |
166 | If any error occurs C<sql_exec> will throw an exception. |
178 | If any error occurs C<sql_exec> will throw an exception. |
167 | |
179 | |
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180 | C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to |
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181 | utf8 before calling the C<execute> method. |
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182 | |
168 | Examples: |
183 | Examples: |
169 | |
184 | |
170 | # easy one |
185 | # easy one |
171 | my $st = sql_exec "select name, id from table where id = ?", $id; |
186 | my $st = sql_exec "select name, id from table where id = ?", $id; |
172 | while (my ($name, $id) = $st->fetchrow_array) { ... }; |
187 | while (my ($name, $id) = $st->fetchrow_array) { ... }; |
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181 | sql_exec $dbh, "update file set name = ?", "oops.txt"; |
196 | sql_exec $dbh, "update file set name = ?", "oops.txt"; |
182 | |
197 | |
183 | |
198 | |
184 | =item sql_fetch <see sql_exec> |
199 | =item sql_fetch <see sql_exec> |
185 | |
200 | |
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201 | =item sql_ufetch <see sql_uexec> |
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202 | |
186 | Execute a sql-statement and fetch the first row of results. Depending on |
203 | Execute an sql-statement and fetch the first row of results. Depending on |
187 | the caller context the row will be returned as a list (array context), or |
204 | the caller context the row will be returned as a list (array context), or |
188 | just the first columns. In table form: |
205 | just the first columns. In table form: |
189 | |
206 | |
190 | CONTEXT RESULT |
207 | CONTEXT RESULT |
191 | void () |
208 | void () |
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202 | |
219 | |
203 | my($name, $amount) = sql_fetch "select ...", args... |
220 | my($name, $amount) = sql_fetch "select ...", args... |
204 | |
221 | |
205 | ... and it's still quite fast unless you fetch large amounts of data. |
222 | ... and it's still quite fast unless you fetch large amounts of data. |
206 | |
223 | |
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224 | C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to |
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225 | utf8 and forces all result values to utf8. |
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226 | |
207 | =item sql_fetchall <see sql_exec> |
227 | =item sql_fetchall <see sql_exec> |
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228 | |
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229 | =item sql_ufetchall <see sql_uexec> |
208 | |
230 | |
209 | Similarly to C<sql_fetch>, but all result rows will be fetched (this is |
231 | Similarly to C<sql_fetch>, but all result rows will be fetched (this is |
210 | of course inefficient for large results!). The context is ignored (only |
232 | of course inefficient for large results!). The context is ignored (only |
211 | list context makes sense), but the result still depends on the number of |
233 | list context makes sense), but the result still depends on the number of |
212 | columns in the result: |
234 | columns in the result: |
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224 | |
246 | |
225 | for (sql_fetchall "select name, age, place from user") { |
247 | for (sql_fetchall "select name, age, place from user") { |
226 | my ($name, $age, $place) = @$_; |
248 | my ($name, $age, $place) = @$_; |
227 | } |
249 | } |
228 | |
250 | |
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251 | C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input |
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252 | values to utf8 and forces all result values to utf8. |
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253 | |
229 | =item sql_exists "<table> where ...", args... |
254 | =item sql_exists "<table> where ...", args... |
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255 | |
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256 | =item sql_uexists <see sql_exists> |
230 | |
257 | |
231 | Check wether the result of the sql-statement "select xxx from |
258 | Check wether the result of the sql-statement "select xxx from |
232 | $first_argument" would be empty or not (that is, imagine the string |
259 | $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 |
260 | "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 |
261 | with every database but can be quite slow, except on mysql, where this |
235 | should be quite fast. |
262 | should be quite fast. |
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263 | |
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264 | C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to |
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265 | utf8. |
236 | |
266 | |
237 | Examples: |
267 | Examples: |
238 | |
268 | |
239 | print "user 7 exists!\n" |
269 | print "user 7 exists!\n" |
240 | if sql_exists "user where id = ?", 7; |
270 | if sql_exists "user where id = ?", 7; |
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314 | |
344 | |
315 | package PApp::SQL::Database; |
345 | package PApp::SQL::Database; |
316 | |
346 | |
317 | =head2 THE DATABASE CLASS |
347 | =head2 THE DATABASE CLASS |
318 | |
348 | |
319 | Again (sigh) the problem of persistency. What do you do when you have to serialize on object |
349 | 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: |
350 | to serialize on object that contains (or should contain) a database |
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351 | 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. |
352 | information to recreate the dbh when needed. |
322 | |
353 | |
323 | The C<PApp::SQL::Database> class does that, in a relatively efficient |
354 | 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 |
355 | fashion: the overhead is currently a single method call per access (you |
325 | can cache the real dbh if you want). |
356 | can cache the real dbh if you want). |
326 | |
357 | |