6 @EXPORT = qw(conv_i conv_date conv_dateq do_query selectrow_query do_statement
7 dump_query quote_db_date
8 selectfirst_hashref_query selectfirst_array_query
9 selectall_hashref_query selectall_array_query
10 prepare_execute_query prepare_query);
13 my ($value, $default) = @_;
14 return (defined($value) && "$value" ne "") ? $value * 1 : $default;
19 return (defined($value) && "$value" ne "") ? $value : undef;
24 if (defined($value) && "$value" ne "") {
25 $value =~ s/\'/\'\'/g;
32 $main::lxdebug->enter_sub(2);
34 my ($form, $dbh, $query) = splice(@_, 0, 3);
36 dump_query(LXDebug::QUERY, '', $query, @_);
38 if (0 == scalar(@_)) {
39 $dbh->do($query) || $form->dberror($query);
41 $dbh->do($query, undef, @_) ||
42 $form->dberror($query . " (" . join(", ", @_) . ")");
45 $main::lxdebug->leave_sub(2);
48 sub selectrow_query { &selectfirst_array_query }
51 $main::lxdebug->enter_sub(2);
53 my ($form, $sth, $query) = splice(@_, 0, 3);
55 dump_query(LXDebug::QUERY, '', $query, @_);
57 if (0 == scalar(@_)) {
58 $sth->execute() || $form->dberror($query);
61 $form->dberror($query . " (" . join(", ", @_) . ")");
64 $main::lxdebug->leave_sub(2);
68 my ($level, $msg, $query) = splice(@_, 0, 3);
70 my $filename = $self_filename = 'SL/DBUtils.pm';
72 while ($filename eq $self_filename) {
73 (undef, $filename, $line, $subroutine) = caller $caller_level++;
76 while ($query =~ /\?/) {
77 my $value = shift(@_);
78 $value =~ s/\'/\\\'/g;
79 $value = "'${value}'";
80 $query =~ s/\?/$value/;
83 $query =~ s/[\n\s]+/ /g;
85 $msg .= " " if ($msg);
87 my $info = "$subroutine called from $filename:$line\n";
89 $main::lxdebug->message($level, $info . $msg . $query);
95 return "NULL" unless defined $str;
96 return "current_date" if $str =~ /current_date/;
103 $main::lxdebug->enter_sub(2);
105 my ($form, $dbh, $query) = splice(@_, 0, 3);
107 dump_query(LXDebug::QUERY, '', $query, @_);
109 my $sth = $dbh->prepare($query) || $form->dberror($query);
111 $main::lxdebug->leave_sub(2);
116 sub prepare_execute_query {
117 $main::lxdebug->enter_sub(2);
119 my ($form, $dbh, $query) = splice(@_, 0, 3);
121 dump_query(LXDebug::QUERY, '', $query, @_);
123 my $sth = $dbh->prepare($query) || $form->dberror($query);
124 if (scalar(@_) != 0) {
125 $sth->execute(@_) || $form->dberror($query . " (" . join(", ", @_) . ")");
127 $sth->execute() || $form->dberror($query);
130 $main::lxdebug->leave_sub(2);
135 sub selectall_hashref_query {
136 $main::lxdebug->enter_sub(2);
138 my ($form, $dbh, $query) = splice(@_, 0, 3);
140 my $sth = prepare_execute_query($form, $dbh, $query, @_);
142 while (my $ref = $sth->fetchrow_hashref()) {
143 push(@{ $result }, $ref);
147 $main::lxdebug->leave_sub(2);
152 sub selectall_array_query {
153 $main::lxdebug->enter_sub(2);
155 my ($form, $dbh, $query) = splice(@_, 0, 3);
157 my $sth = prepare_execute_query($form, $dbh, $query, @_);
159 while (my ($value) = $sth->fetchrow_array()) {
160 push(@result, $value);
164 $main::lxdebug->leave_sub(2);
169 sub selectfirst_hashref_query {
170 $main::lxdebug->enter_sub(2);
172 my ($form, $dbh, $query) = splice(@_, 0, 3);
174 my $sth = prepare_execute_query($form, $dbh, $query, @_);
175 my $ref = $sth->fetchrow_hashref();
178 $main::lxdebug->leave_sub(2);
183 sub selectfirst_array_query {
184 $main::lxdebug->enter_sub(2);
186 my ($form, $dbh, $query) = splice(@_, 0, 3);
188 my $sth = prepare_execute_query($form, $dbh, $query, @_);
189 my @ret = $sth->fetchrow_array();
192 $main::lxdebug->leave_sub(2);
204 SL::DBUTils.pm: All about Databaseconections in Lx
210 conv_i($str, $default)
215 do_query($form, $dbh, $query)
216 do_statement($form, $sth, $query)
218 dump_query($level, $msg, $query)
219 prepare_execute_query($form, $dbh, $query)
221 my $all_results_ref = selectall_hashref_query($form, $dbh, $query)
222 my $first_result_hash_ref = selectfirst_hashref_query($form, $dbh, $query);
224 my @first_result = selectfirst_array_query($form, $dbh, $query); # ==
225 my @first_result = selectrow_query($form, $dbh, $query);
230 DBUtils is the attempt to reduce the amount of overhead it takes to retrieve information from the database in Lx-Office. Previously it would take about 15 lines of code just to get one single integer out of the database, including failure procedures and importing the necessary packages. Debugging would take even more.
232 Using DBUtils most database procedures can be reduced to defining the query, executing it, and retrieving the result. Let DBUtils handle the rest. Whenever there is a database operation not covered in DBUtils, add it here, rather than working around it in the backend code.
234 DBUtils relies heavily on two parameters which have to be passed to almost every function: $form and $dbh.
235 - $form is used for error handling only. It can be omitted in theory, but should not.
236 - $dbh is a handle to the databe, as returned by the DBI::connect routine. If you don't have an active connectiong, you can query $form->get_standard_dbh() to get a generic no_auto connection. Don't forget to commit in this case!
239 Every function here should accomplish the follwing things:
240 - Easy debugging. Every handled query gets dumped via LXDebug, if specified there.
241 - Safe value binding. Although DBI is far from perfect in terms of binding, the rest of the bindings should happen here.
242 - Error handling. Should a query fail, an error message will be generated here instead of in the backend code invoking DBUtils.
244 Note that binding is not perfect here either...
246 =head2 QUOTING FUNCTIONS
252 =item conv_i STR,DEFAULT
254 Converts STR to an integer. If STR is empty, returns DEFAULT. If no DEFAULT is given, returns undef.
258 Converts STR to a date string. If STR is emptry, returns undef.
262 Database version of conv_date. Quotes STR before returning. Returns 'NULL' if STR is empty.
264 =item quote_db_date STR
266 Treats STR as a database date, quoting it. If STR equals current_date returns an escaped version which is treated as the current date by Postgres.
267 Returns 'NULL' if STR is empty.
271 =head2 QUERY FUNCTIONS
275 =item do_query FORM,DBH,QUERY,ARRAY
277 Uses DBI::do to execute QUERY on DBH using ARRAY for binding values. FORM is only needed for error handling, but should always be passed nevertheless. Use this for insertions or updates that don't need to be prepared.
279 =item do_statement FORM,STH,QUERY,ARRAY
281 Uses DBI::execute to execute QUERY on DBH using ARRAY for binding values. As with do_query, FORM is only used for error handling. If you are unsure what to use, refer to the documentation of DBI::do and DBI::execute.
283 =item prepare_execute_query FORM,DBH,QUERY,ARRAY
285 Prepares and executes QUERY on DBH using DBI::prepare and DBI::execute. ARRAY is passed as binding values to execute.
289 =head2 RETRIEVAL FUNCTIONS
293 =item selectfirst_array_query FORM,DBH,QUERY,ARRAY
295 =item selectrow_query FORM,DBH,QUERY,ARRAY
297 Prepares and executes a query using DBUtils functions, retireves the first row from the database, and returns it as an arrayref of the first row.
299 =item selectfirst_hashref_query FORM,DBH,QUERY,ARRAY
301 Prepares and executes a query using DBUtils functions, retireves the first row from the database, and returns it as a hashref of the first row.
303 =item selectall_hashref_query FORM,DBH,QUERY,ARRAY
305 Prepares and executes a query using DBUtils functions, retireves all data from the database, and returns it in hashref mode. This is slightly confusing, as the data structure will actually be a reference to an array, containing hashrefs for each row.
309 =head2 DEBUG FUNCTIONS
313 =item dump_query LEVEL,MSG,QUERY,ARRAY
315 Dumps a query using LXDebug->message, using LEVEL for the debug-level of LXDebug. If MSG is given, it preceeds the QUERY dump in the logfiles. ARRAY is used to interpolate the '?' placeholders in QUERY, the resulting QUERY can be copy-pasted into a database frontend for debugging. Note that this method is also automatically called by each of the other QUERY FUNCTIONS, so there is in general little need to invoke it manually.
323 =item Retrieving a whole table:
325 $query = qq|SELECT id, pricegroup FROM pricegroup|;
326 $form->{PRICEGROUPS} = selectall_hashref_query($form, $dbh, $query);
328 =item Retrieving a single value:
330 $query = qq|SELECT nextval('glid')|;
331 ($new_id) = selectrow_query($form, $dbh, $query);
333 =item Using binding values:
335 $query = qq|UPDATE ar SET paid = amount + paid, storno = 't' WHERE id = ?|;
336 do_query($form, $dbh, $query, $id);
338 =item A more complicated example, using dynamic binding values:
342 if ($form->{language_values} ne "") {
343 $query = qq|SELECT l.id, l.description, tr.translation, tr.longdescription
345 LEFT OUTER JOIN translation tr ON (tr.language_id = l.id) AND (tr.parts_id = ?)|;
346 @values = (conv_i($form->{id}));
348 $query = qq|SELECT id, description FROM language|;
351 my $languages = selectall_hashref_query($form, $dbh, $query, @values);
357 =head1 MODULE AUTHORS
359 Moritz Bunkus E<lt>m.bunkus@linet-services.deE<gt>
360 Sven Schoeling E<lt>s.schoeling@linet-services.deE<gt>
362 =head1 DOCUMENTATION AUTHORS
364 Udo Spallek E<lt>udono@gmx.netE<gt>
365 Sven Schoeling E<lt>s.schoeling@linet-services.deE<gt>
367 =head1 COPYRIGHT AND LICENSE
369 Copyright 2007 by Lx-Office Community
371 This program is free software; you can redistribute it and/or modify
372 it under the terms of the GNU General Public License as published by
373 the Free Software Foundation; either version 2 of the License, or
374 (at your option) any later version.
376 This program is distributed in the hope that it will be useful,
377 but WITHOUT ANY WARRANTY; without even the implied warranty of
378 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
379 GNU General Public License for more details.
380 You should have received a copy of the GNU General Public License
381 along with this program; if not, write to the Free Software
382 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.