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 | |
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9 | my $st = sql_exec $DBH, "select ... where a = ?", $a; |
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10 | |
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11 | local $DBH = <database handle>; |
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12 | my $st = sql_exec \my($bind_a, $bind_b), "select a,b ..."; |
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13 | my $st = sql_insertid |
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14 | sql_exec "insert into ... values (?, ?)", $v1, $v2; |
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15 | my $a = sql_fetch "select a from ..."; |
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16 | sql_fetch \my($a, $b), "select a,b ..."; |
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17 | |
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18 | sql_exists "table where name like 'a%'" |
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19 | or die "a* required but not existent"; |
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20 | |
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21 | my $db = new PApp::SQL::Database "", "DBI:mysql:test", "user", "pass"; |
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22 | local $PApp::SQL::DBH = $db->checked_dbh; # does 'ping' |
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23 | |
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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 |
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31 | should work with anything from perl-5.004_01 onwards, but I only support |
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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. |
15 | |
34 | |
16 | =over 4 |
35 | If the descriptions here seem terse or if you always wanted to know |
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36 | what PApp is then have a look at the PApp module which uses this module |
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37 | extensively but also provides you with a lot more gimmicks to play around |
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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 | |
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24 | #use PApp::Exception; # not yet used |
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25 | |
45 | |
26 | BEGIN { |
46 | BEGIN { |
27 | use base Exporter; |
47 | use base qw(Exporter DynaLoader); |
28 | |
48 | |
29 | $VERSION = 0.11; |
49 | $VERSION = 0.143; |
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 |
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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; |
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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; |
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66 | |
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67 | =head2 GLOBAL VARIABLES |
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68 | |
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69 | =over 4 |
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70 | |
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71 | =item $sql_exec |
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72 | |
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73 | Since the C<sql_exec> family of functions return a statement handle there |
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74 | must be another way to test the return value of the C<execute> call. This |
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75 | global variable contains the result of the most recent call to C<execute> |
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76 | done by this module. |
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77 | |
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78 | =item $PApp::SQL::DBH |
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79 | |
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80 | The default database handle used by this module if no C<$DBH> was |
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81 | specified as argument. See C<sql_exec> for a discussion. |
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82 | |
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83 | =item $PApp::SQL::Database |
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84 | |
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85 | The current default C<PApp::SQL::Database>-object. Future versions might |
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86 | automatically fall back on this database and create database handles from |
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87 | it if neccessary. At the moment this is not used by this module but might |
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88 | be nice as a placeholder for the database object that corresponds to |
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89 | $PApp::SQL::DBH. |
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90 | |
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91 | =back |
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92 | |
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93 | =head2 FUNCTIONS |
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94 | |
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95 | =over 4 |
46 | |
96 | |
47 | =item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect |
97 | =item $dbh = connect_cached $id, $dsn, $user, $pass, $flags, $connect |
48 | |
98 | |
49 | (not exported by by default) |
99 | (not exported by by default) |
50 | |
100 | |
… | |
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60 | __LINE__ work fine as well). |
110 | __LINE__ work fine as well). |
61 | |
111 | |
62 | The reason C<$id> is necessary is that you might specify special connect |
112 | The reason C<$id> is necessary is that you might specify special connect |
63 | 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 |
64 | differently than maybe other applications requesting the same database |
114 | differently than maybe other applications requesting the same database |
65 | 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 |
66 | leave $id empty (i.e. ""). |
116 | leave C<$id> empty (i.e. ""). |
67 | |
117 | |
68 | 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 |
69 | 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 |
70 | C<$dbh> as first argument. |
120 | C<$dbh> as first argument. |
71 | |
121 | |
72 | Examples: |
122 | Examples: |
73 | |
123 | |
74 | # try your luck opening the papp database without access info |
124 | # try your luck opening the papp database without access info |
75 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
125 | $dbh = connect_cached __FILE__, "DBI:mysql:papp"; |
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126 | |
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127 | Mysql-specific behaviour: The default setting of |
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128 | C<mysql_client_found_rows> is TRUE, you can overwrite this, though. |
76 | |
129 | |
77 | =cut |
130 | =cut |
78 | |
131 | |
79 | sub connect_cached { |
132 | sub connect_cached { |
80 | my ($id, $dsn, $user, $pass, $flags, $connect) = @_; |
133 | my ($id, $dsn, $user, $pass, $flags, $connect) = @_; |
81 | # the following line is duplicated in PApp::SQL::Database::new |
134 | # the following line is duplicated in PApp::SQL::Database::new |
82 | $id = "$id\0$dsn\0$user\0$pass"; |
135 | $id = "$id\0$dsn\0$user\0$pass"; |
83 | unless ($dbcache{$id} && $dbcache{$id}->ping) { |
136 | unless ($dbcache{$id} && $dbcache{$id}->ping) { |
84 | #warn "connecting to ($dsn|$user|$pass|$flags)\n";#d# |
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85 | # first, nuke our statement cache (sooory ;) |
137 | # first, nuke our statement cache (sooory ;) |
86 | cachesize cachesize 0; |
138 | cachesize cachesize 0; |
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139 | |
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140 | # then make mysql behave more standardly by default |
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141 | $dsn =~ /^[Dd][Bb][Ii]:mysql:/ |
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142 | and $dsn !~ /;mysql_client_found_rows/ |
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143 | and $dsn .= ";mysql_client_found_rows=1"; |
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144 | |
87 | # then connect anew |
145 | # then connect anew |
88 | $dbcache{$id} = |
146 | $dbcache{$id} = |
89 | eval { DBI->connect($dsn, $user, $pass, $flags) } |
147 | eval { DBI->connect($dsn, $user, $pass, $flags) } |
90 | || eval { DBI->connect($dsn, $user, $pass, $flags) } |
148 | || eval { DBI->connect($dsn, $user, $pass, $flags) } |
91 | || die "unable to connect to database $dsn: $DBI::errstr\n"; |
149 | || die "unable to connect to database $dsn: $DBI::errstr\n"; |
… | |
… | |
94 | $dbcache{$id}; |
152 | $dbcache{$id}; |
95 | } |
153 | } |
96 | |
154 | |
97 | =item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] |
155 | =item $sth = sql_exec [dbh,] [bind-vals...,] "sql-statement", [arguments...] |
98 | |
156 | |
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157 | =item $sth = sql_uexec <see sql_exec> |
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158 | |
99 | C<sql_exec> is the most important and most-used function in this module. |
159 | C<sql_exec> is the most important and most-used function in this module. |
100 | |
160 | |
101 | Runs the given sql command with the given parameters and returns the |
161 | Runs the given sql command with the given parameters and returns the |
102 | statement handle. The command and the statement handle will be cached |
162 | statement handle. The command and the statement handle will be cached |
103 | (with the database handle and the sql string as key), so prepare will be |
163 | (with the database handle and the sql string as key), so prepare will be |
104 | called only once for each distinct sql call (please keep in mind that the |
164 | called only once for each distinct sql call (please keep in mind that the |
105 | returned statement will always be the same, so, if you call C<sql_exec> |
165 | returned statement will always be the same, so, if you call C<sql_exec> |
106 | with the same dbh and sql-statement twice (e.g. in a subroutine you |
166 | with the same dbh and sql-statement twice (e.g. in a subroutine you |
107 | called), the statement handle for the first call mustn't be used. |
167 | called), the statement handle for the first call mustn't not be in use |
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168 | anymore, as the subsequent call will re-use the handle. |
108 | |
169 | |
109 | The database handle (the first argument) is optional. If it is missing, |
170 | The database handle (the first argument) is optional. If it is missing, |
110 | C<sql_exec> first tries to use the variable C<$DBH> in the current (= |
171 | it tries to use database handle in C<$PApp::SQL::DBH>, which you can set |
111 | calling) package and, if that fails, it tries to use database handle in |
172 | before calling these functions. NOTICE: future and former versions of |
112 | C<$PApp::SQL::DBH>, which you can set before calling these functions. |
173 | PApp::SQL might also look up the global variable C<$DBH> in the callers |
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174 | package. |
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175 | |
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176 | =begin comment |
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177 | |
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178 | If it is missing, C<sql_exec> first tries to use the variable C<$DBH> |
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179 | in the current (= calling) package and, if that fails, it tries to use |
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180 | database handle in C<$PApp::SQL::DBH>, which you can set before calling |
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181 | these functions. |
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182 | |
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183 | =end comment |
113 | |
184 | |
114 | The actual return value from the C<$sth->execute> call is stored in the |
185 | The actual return value from the C<$sth->execute> call is stored in the |
115 | package-global (and exported) variable C<$sql_exec>. |
186 | package-global (and exported) variable C<$sql_exec>. |
116 | |
187 | |
117 | If any error occurs C<sql_exec> will throw an exception. |
188 | If any error occurs C<sql_exec> will throw an exception. |
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189 | |
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190 | C<sql_uexec> is similar to C<sql_exec> but upgrades all input arguments to |
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191 | UTF-8 before calling the C<execute> method. |
118 | |
192 | |
119 | Examples: |
193 | Examples: |
120 | |
194 | |
121 | # easy one |
195 | # easy one |
122 | 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; |
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132 | sql_exec $dbh, "update file set name = ?", "oops.txt"; |
206 | sql_exec $dbh, "update file set name = ?", "oops.txt"; |
133 | |
207 | |
134 | |
208 | |
135 | =item sql_fetch <see sql_exec> |
209 | =item sql_fetch <see sql_exec> |
136 | |
210 | |
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211 | =item sql_ufetch <see sql_uexec> |
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212 | |
137 | Execute a sql-statement and fetch the first row of results. Depending on |
213 | Execute an sql-statement and fetch the first row of results. Depending on |
138 | the caller context the row will be returned as a list (array context), or |
214 | the caller context the row will be returned as a list (array context), or |
139 | just the first columns. In table form: |
215 | just the first columns. In table form: |
140 | |
216 | |
141 | CONTEXT RESULT |
217 | CONTEXT RESULT |
142 | void () |
218 | void () |
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153 | |
229 | |
154 | my($name, $amount) = sql_fetch "select ...", args... |
230 | my($name, $amount) = sql_fetch "select ...", args... |
155 | |
231 | |
156 | ... 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. |
157 | |
233 | |
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234 | C<sql_ufetch> is similar to C<sql_fetch> but upgrades all input values to |
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235 | UTF-8 and forces all result values to UTF-8 (this does I<not> include result |
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236 | parameters, only return values. Using bind variables in conjunction with |
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237 | sql_u* functions might result in undefined behaviour - we use UTF-8 on |
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238 | bind-variables at execution time and it seems to work on DBD::mysql as it |
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239 | ignores the UTF-8 bit completely. Which just means that that DBD-driver is |
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240 | broken). |
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241 | |
158 | =item sql_fetchall <see sql_exec> |
242 | =item sql_fetchall <see sql_exec> |
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243 | |
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244 | =item sql_ufetchall <see sql_uexec> |
159 | |
245 | |
160 | 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 |
161 | of course inefficient for large results!). The context is ignored (only |
247 | of course inefficient for large results!). The context is ignored (only |
162 | 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 |
163 | columns in the result: |
249 | columns in the result: |
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175 | |
261 | |
176 | for (sql_fetchall "select name, age, place from user") { |
262 | for (sql_fetchall "select name, age, place from user") { |
177 | my ($name, $age, $place) = @$_; |
263 | my ($name, $age, $place) = @$_; |
178 | } |
264 | } |
179 | |
265 | |
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266 | C<sql_ufetchall> is similar to C<sql_fetchall> but upgrades all input |
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267 | values to UTF-8 and forces all result values to UTF-8 (see the caveats in |
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268 | the description of C<sql_ufetch>, though). |
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269 | |
180 | =item sql_exists "<table> where ...", args... |
270 | =item sql_exists "<table_references> where <where_condition>...", args... |
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271 | |
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272 | =item sql_uexists <see sql_exists> |
181 | |
273 | |
182 | Check wether the result of the sql-statement "select xxx from |
274 | Check wether the result of the sql-statement "select xxx from |
183 | $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 |
184 | "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 |
185 | 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 |
186 | should be quite fast. |
278 | should be quite fast. |
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279 | |
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280 | C<sql_uexists> is similar to C<sql_exists> but upgrades all parameters to |
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281 | UTF-8. |
187 | |
282 | |
188 | Examples: |
283 | Examples: |
189 | |
284 | |
190 | print "user 7 exists!\n" |
285 | print "user 7 exists!\n" |
191 | if sql_exists "user where id = ?", 7; |
286 | if sql_exists "user where id = ?", 7; |
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226 | |
321 | |
227 | =item [old-size] = cachesize [new-size] |
322 | =item [old-size] = cachesize [new-size] |
228 | |
323 | |
229 | 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 |
230 | default is somewhere around 50 (= the 50 last recently used statements |
325 | default is somewhere around 50 (= the 50 last recently used statements |
231 | 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 |
232 | 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 |
233 | is actually quite fast). |
328 | is actually quite fast). |
234 | |
329 | |
235 | 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, |
236 | 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 |
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241 | |
336 | |
242 | =cut |
337 | =cut |
243 | |
338 | |
244 | =item reinitialize [not exported] |
339 | =item reinitialize [not exported] |
245 | |
340 | |
246 | Clears any internal caches (statement cache, database handle cache). |
341 | Clears any internal caches (statement cache, database handle |
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342 | cache). Should be called after C<fork> and other accidents that invalidate |
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343 | database handles. |
247 | |
344 | |
248 | =cut |
345 | =cut |
249 | |
346 | |
250 | sub reinitialize { |
347 | sub reinitialize { |
251 | cachesize cachesize 0; |
348 | cachesize cachesize 0; |
252 | for (values %dbcache) { |
349 | for (values %dbcache) { |
253 | eval { $_->disconnect }; |
350 | eval { $_->{InactiveDestroy} = 1 }; |
254 | } |
351 | } |
255 | undef %dbcache; |
352 | undef %dbcache; |
256 | } |
353 | } |
257 | |
354 | |
258 | =back |
355 | =back |
… | |
… | |
263 | |
360 | |
264 | package PApp::SQL::Database; |
361 | package PApp::SQL::Database; |
265 | |
362 | |
266 | =head2 THE DATABASE CLASS |
363 | =head2 THE DATABASE CLASS |
267 | |
364 | |
268 | 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 |
269 | 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 |
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367 | handle? Short answer: you don't. Long answer: you can embed the necessary |
270 | you can embed the necessary information to recreate the dbh when needed. |
368 | information to recreate the dbh when needed. |
271 | |
369 | |
272 | 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 |
273 | 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 |
274 | can cache the real dbh if you want). |
372 | can cache the real dbh if you want). |
275 | |
373 | |
… | |
… | |
315 | |
413 | |
316 | =item $db->dsn |
414 | =item $db->dsn |
317 | |
415 | |
318 | 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). |
319 | |
417 | |
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418 | =item $db->login |
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419 | |
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420 | Return the login name. |
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421 | |
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422 | =item $db->password |
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423 | |
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424 | Return the password (emphasizing the fact that the password is stored plaintext ;) |
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425 | |
320 | =cut |
426 | =cut |
321 | |
427 | |
322 | sub dsn($) { |
428 | sub dsn($) { |
323 | my $self = shift; |
429 | my $self = shift; |
324 | $self->[1][1]; |
430 | (split /\x00/, $self->[0])[1]; |
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431 | } |
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432 | |
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433 | sub login($) { |
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434 | my $self = shift; |
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435 | (split /\x00/, $self->[0])[2]; |
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436 | } |
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437 | |
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438 | sub password($) { |
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439 | my $self = shift; |
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440 | (split /\x00/, $self->[0])[3]; |
325 | } |
441 | } |
326 | |
442 | |
327 | =back |
443 | =back |
328 | |
444 | |
329 | =cut |
445 | =cut |
330 | |
446 | |
331 | 1; |
447 | 1; |
332 | |
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333 | =head1 BUGS |
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334 | |
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335 | As of this writing, sql_fetch and sql_fetchall are not very well tested |
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336 | (they were just re-written in C). |
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337 | |
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338 | sql_exists could be faster (it is written very ugly to not change the |
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339 | current package). |
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340 | |
448 | |
341 | =head1 SEE ALSO |
449 | =head1 SEE ALSO |
342 | |
450 | |
343 | L<PApp>. |
451 | L<PApp>. |
344 | |
452 | |