1 package SQL::Translator::Diff;
4 ## SQLT schema diffing code
9 use SQL::Translator::Schema::Constants;
11 use base 'Class::Accessor::Fast';
13 # Input/option accessors
14 __PACKAGE__->mk_accessors(qw/
15 ignore_index_names ignore_constraint_names ignore_view_sql
16 ignore_proc_sql output_db source_schema source_db target_schema target_db
17 case_insensitive no_batch_alters ignore_missing_methods
25 my @diff_hash_keys = qw/
37 __PACKAGE__->mk_accessors(@diff_arrays, 'table_diff_hash');
41 ## we are getting instructions on how to turn the source into the target
42 ## source == original, target == new (hmm, if I need to comment this, should I rename the vars again ??)
43 ## _schema isa SQL::Translator::Schema
44 ## _db is the name of the producer/db it came out of/into
45 ## results are formatted to the source preferences
47 my ($source_schema, $source_db, $target_schema, $target_db, $options) = @_;
50 my $obj = SQL::Translator::Diff->new( {
52 source_schema => $source_schema,
53 source_db => $source_db,
54 target_schema => $target_schema,
55 target_db => $target_db
58 $obj->compute_differences->produce_diff_sql;
62 my ($class, $values) = @_;
63 $values->{$_} ||= [] foreach @diff_arrays;
64 $values->{table_diff_hash} = {};
66 $values->{output_db} ||= $values->{source_db};
67 return $class->SUPER::new($values);
70 sub compute_differences {
73 my $target_schema = $self->target_schema;
74 my $source_schema = $self->source_schema;
76 my $producer_class = "SQL::Translator::Producer::@{[$self->output_db]}";
77 eval "require $producer_class";
80 if (my $preprocess = $producer_class->can('preprocess_schema')) {
81 $producer_class->$preprocess($source_schema);
83 $producer_class->$preprocess($target_schema);
86 my @tar_tables = sort { $a->name cmp $b->name } $target_schema->get_tables;
87 ## do original/source tables exist in target?
88 for my $tar_table ( @tar_tables ) {
89 my $tar_table_name = $tar_table->name;
90 $DB::single = 1 if $tar_table_name eq 'admin_contest';
91 my $src_table = $source_schema->get_table( $tar_table_name, $self->case_insensitive );
93 unless ( $src_table ) {
95 ## add table(s) later.
96 push @{$self->tables_to_create}, $tar_table;
100 $self->table_diff_hash->{$tar_table_name} = {
101 map {$_ => [] } @diff_hash_keys
104 $self->diff_table_options($src_table, $tar_table);
106 ## Compare fields, their types, defaults, sizes etc etc
107 $self->diff_table_fields($src_table, $tar_table);
109 $self->diff_table_indexes($src_table, $tar_table);
110 $self->diff_table_constraints($src_table, $tar_table);
112 } # end of target_schema->get_tables loop
114 for my $src_table ( $source_schema->get_tables ) {
115 my $src_table_name = $src_table->name;
116 my $tar_table = $target_schema->get_table( $src_table_name, $self->case_insensitive );
118 unless ( $tar_table ) {
119 $self->table_diff_hash->{$src_table_name} = {
120 map {$_ => [] } @diff_hash_keys
123 push @{ $self->tables_to_drop}, $src_table;
131 sub produce_diff_sql {
134 my $target_schema = $self->target_schema;
135 my $source_schema = $self->source_schema;
136 my $tar_name = $target_schema->name;
137 my $src_name = $source_schema->name;
139 my $producer_class = "SQL::Translator::Producer::@{[$self->output_db]}";
140 eval "require $producer_class";
143 # Map of name we store under => producer method name
145 constraints_to_create => 'alter_create_constraint',
146 constraints_to_drop => 'alter_drop_constraint',
147 indexes_to_create => 'alter_create_index',
148 indexes_to_drop => 'alter_drop_index',
149 fields_to_create => 'add_field',
150 fields_to_alter => 'alter_field',
151 fields_to_rename => 'rename_field',
152 fields_to_drop => 'drop_field',
153 table_options => 'alter_table'
157 if (!$self->no_batch_alters &&
158 (my $batch_alter = $producer_class->can('batch_alter_table')) )
160 # Good - Producer supports batch altering of tables.
161 foreach my $table ( sort keys %{$self->table_diff_hash} ) {
162 my $tar_table = $target_schema->get_table($table)
163 || $source_schema->get_table($table);
165 push @diffs, $batch_alter->($tar_table,
167 $func_map{$_} => $self->table_diff_hash->{$table}{$_}
175 foreach my $table ( sort keys %{$self->table_diff_hash} ) {
176 my $table_diff = $self->table_diff_hash->{$table};
177 for (@diff_hash_keys) {
178 push( @{ $flattened_diffs{ $func_map{$_} } ||= [] }, @{ $table_diff->{$_} } );
183 if (@{$flattened_diffs{$_}}) {
184 my $meth = $producer_class->can($_);
186 $meth ? map { my $sql = $meth->(ref $_ eq 'ARRAY' ? @$_ : $_); $sql ? ("$sql;") : () } @{ $flattened_diffs{$_} }
187 : $self->ignore_missing_methods
188 ? "-- $producer_class cant $_"
189 : die "$producer_class cant $_";
192 } qw/alter_drop_constraint
199 alter_create_constraint
203 if (my @tables = @{ $self->tables_to_create } ) {
204 my $translator = new SQL::Translator(
205 producer_type => $self->output_db,
208 # TODO: sort out options
209 quote_table_names => 0,
210 quote_field_names => 0,
212 my $schema = $translator->schema;
214 $schema->add_table($_) for @tables;
217 # Remove begin/commit here, since we wrap everything in one.
218 grep { $_ !~ /^(?:COMMIT|BEGIN(?: TRANSACTION)?);/ } $producer_class->can('produce')->($translator);
221 if (my @tables_to_drop = @{ $self->{tables_to_drop} || []} ) {
222 my $meth = $producer_class->can('drop_table');
224 push @diffs, $meth ? map( { $meth->($_) } @tables_to_drop )
225 : $self->ignore_missing_methods
226 ? "-- $producer_class cant drop_table"
227 : die "$producer_class cant drop_table";
231 unshift @diffs, "BEGIN TRANSACTION;\n";
232 push @diffs, "\nCOMMIT;\n";
234 @diffs = ("-- No differences found\n\n");
238 if ( $self->target_db !~ /^(?:MySQL|SQLite)$/ ) {
239 unshift(@diffs, "-- Target database @{[$self->target_db]} is untested/unsupported!!!");
241 return join( "\n", "-- Convert schema '$src_name' to '$tar_name':\n", @diffs);
247 sub diff_table_indexes {
248 my ($self, $src_table, $tar_table) = @_;
250 my (%checked_indices);
252 for my $i_tar ( $tar_table->get_indices ) {
253 for my $i_src ( $src_table->get_indices ) {
254 if ( $i_tar->equals($i_src, $self->case_insensitive, $self->ignore_index_names) ) {
255 $checked_indices{$i_src} = 1;
259 push @{$self->table_diff_hash->{$tar_table}{indexes_to_create}}, $i_tar;
263 for my $i_src ( $src_table->get_indices ) {
264 next if !$self->ignore_index_names && $checked_indices{$i_src};
265 for my $i_tar ( $tar_table->get_indices ) {
266 next INDEX_DROP if $i_src->equals($i_tar, $self->case_insensitive, $self->ignore_index_names);
268 push @{$self->table_diff_hash->{$tar_table}{indexes_to_drop}}, $i_src;
273 sub diff_table_constraints {
274 my ($self, $src_table, $tar_table) = @_;
276 my(%checked_constraints);
278 for my $c_tar ( $tar_table->get_constraints ) {
279 for my $c_src ( $src_table->get_constraints ) {
280 if ( $c_tar->equals($c_src, $self->case_insensitive, $self->ignore_constraint_names) ) {
281 $checked_constraints{$c_src} = 1;
282 next CONSTRAINT_CREATE;
285 push @{ $self->table_diff_hash->{$tar_table}{constraints_to_create} }, $c_tar;
290 for my $c_src ( $src_table->get_constraints ) {
291 next if !$self->ignore_constraint_names && $checked_constraints{$c_src};
292 for my $c_tar ( $tar_table->get_constraints ) {
293 next CONSTRAINT_DROP if $c_src->equals($c_tar, $self->case_insensitive, $self->ignore_constraint_names);
296 push @{ $self->table_diff_hash->{$tar_table}{constraints_to_drop} }, $c_src;
301 sub diff_table_fields {
302 my ($self, $src_table, $tar_table) = @_;
304 # List of ones ew've renamed from so we dont drop them
305 my %renamed_source_fields;
307 for my $tar_table_field ( $tar_table->get_fields ) {
308 my $f_tar_name = $tar_table_field->name;
310 $DB::single = 1 if $f_tar_name eq 'invite_type';
311 if (my $old_name = $tar_table_field->extra->{renamed_from}) {
312 my $src_table_field = $src_table->get_field( $old_name, $self->case_insensitive );
313 die qq#Renamed cant find "@{[$src_table->name]}.$old_name" for renamed column\n# unless $src_table_field;
314 push @{$self->table_diff_hash->{$tar_table}{fields_to_rename} }, [ $src_table_field, $tar_table_field ];
315 $renamed_source_fields{$old_name} = 1;
319 my $src_table_field = $src_table->get_field( $f_tar_name, $self->case_insensitive );
321 unless ( $src_table_field ) {
322 push @{$self->table_diff_hash->{$tar_table}{fields_to_create}}, $tar_table_field;
326 # field exists, something changed. This is a bit complex. Parsers can
327 # normalize types, but only some of them do, so compare the normalized and
328 # parsed types for each field to each other
329 if ( !$tar_table_field->equals($src_table_field, $self->case_insensitive) &&
330 !$tar_table_field->equals($src_table_field->parsed_field, $self->case_insensitive) &&
331 !$tar_table_field->parsed_field->equals($src_table_field, $self->case_insensitive) &&
332 !$tar_table_field->parsed_field->equals($src_table_field->parsed_field, $self->case_insensitive) ) {
334 # Some producers might need src field to diff against
335 push @{$self->table_diff_hash->{$tar_table}{fields_to_alter}}, [ $src_table_field, $tar_table_field ];
341 # Now check to see if any fields from src_table need to be dropped
342 for my $src_table_field ( $src_table->get_fields ) {
343 my $f_src_name = $src_table_field->name;
344 next if $renamed_source_fields{$f_src_name};
346 my $tar_table_field = $tar_table->get_field( $f_src_name, $self->case_insensitive );
348 unless ( $tar_table_field ) {
349 push @{$self->table_diff_hash->{$tar_table}{fields_to_drop}}, $src_table_field;
355 sub diff_table_options {
356 my ($self, $src_table, $tar_table) = @_;
359 # If there's a difference, just re-set all the options
360 push @{ $self->table_diff_hash->{$tar_table}{table_options} }, $tar_table
361 unless $src_table->_compare_objects( scalar $src_table->options, scalar $tar_table->options );
370 SQL::Translator::Diff
374 Takes two input SQL::Translator::Schemas (or SQL files) and produces ALTER
375 statments to make them the same
381 use SQL::Translator::Diff;
382 my $sql = SQL::Translator::Diff::schema_diff($source_schema, 'MySQL', $target_schema, 'MySQL', $options_hash)
386 use SQL::Translator::Diff;
387 my $diff = SQL::Translator::Diff->new({
388 output_db => 'MySQL',
389 source_schema => $source_schema,
390 target_schema => $target_schema,
392 })->compute_differences->produce_diff_sql;
398 =item B<ignore_index_names>
400 Match indexes based on types and fields, ignoring name.
402 =item B<ignore_constraint_names>
404 Match constrains based on types, fields and tables, ignoring name.
408 Which producer to use to produce the output.
410 =item B<case_insensitive>
412 Ignore case of table, field, index and constraint names when comparing
414 =item B<no_batch_alters>
416 Produce each alter as a distinct C<ALTER TABLE> statement even if the producer
417 supports the ability to do all alters for a table as one statement.
419 =item B<ignore_missing_methods>
421 If the diff would need a method that is missing from the producer, just emit a
422 comment showing the method is missing, rather than dieing with an error
426 =head1 PRODUCER FUNCTIONS
428 The following producer functions should be implemented for completeness. If
429 any of them are needed for a given diff, but not found, an error will be
434 =item * C<alter_create_constraint($con)>
436 =item * C<alter_drop_constraint($con)>
438 =item * C<alter_create_index($idx)>
440 =item * C<alter_drop_index($idx)>
442 =item * C<add_field($fld)>
444 =item * C<alter_field($old_fld, $new_fld)>
446 =item * C<rename_field($old_fld, $new_fld)>
448 =item * C<drop_field($fld)>
450 =item * C<alter_table($table)>
452 =item * C<drop_table($table)>
454 =item * C<batch_alter_table($table, $hash)> (optional)
458 If the producer supports C<batch_alter_table>, it will be called with the
459 table to alter and a hash, the keys of which will be the method names listed
460 above; values will be arrays of fields or constraints to operate on. In the
461 case of the field functions that take two arguments this will appear as a hash.
463 I.e. the hash might look something like the following:
466 alter_create_constraint => [ $constraint1, $constraint2 ],
467 add_field => [ $field ],
468 alter_field => [ [$old_field, $new_field] ]
473 Original Author(s) unknown.
475 Refactor and more comprehensive tests by Ash Berlin C<< ash@cpan.org >>.
477 Redevelopment sponsored by Takkle Inc.