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 @tar_tables = sort { $a->name cmp $b->name } $target_schema->get_tables;
77 ## do original/source tables exist in target?
78 for my $tar_table ( @tar_tables ) {
79 my $tar_table_name = $tar_table->name;
80 my $src_table = $source_schema->get_table( $tar_table_name, $self->case_insensitive );
82 unless ( $src_table ) {
84 ## add table(s) later.
85 push @{$self->tables_to_create}, $tar_table;
89 $self->table_diff_hash->{$tar_table_name} = {
90 map {$_ => [] } @diff_hash_keys
93 $self->diff_table_options($src_table, $tar_table);
95 ## Compare fields, their types, defaults, sizes etc etc
96 $self->diff_table_fields($src_table, $tar_table);
98 $self->diff_table_indexes($src_table, $tar_table);
99 $self->diff_table_constraints($src_table, $tar_table);
101 } # end of target_schema->get_tables loop
103 for my $src_table ( $source_schema->get_tables ) {
104 my $src_table_name = $src_table->name;
105 my $tar_table = $target_schema->get_table( $src_table_name, $self->case_insensitive );
107 unless ( $tar_table ) {
108 $self->table_diff_hash->{$src_table_name} = {
109 map {$_ => [] } @diff_hash_keys
112 push @{ $self->tables_to_drop}, $src_table;
120 sub produce_diff_sql {
123 my $target_schema = $self->target_schema;
124 my $source_schema = $self->source_schema;
125 my $tar_name = $target_schema->name;
126 my $src_name = $source_schema->name;
128 my $producer_class = "SQL::Translator::Producer::@{[$self->output_db]}";
129 eval "require $producer_class";
132 # Map of name we store under => producer method name
134 constraints_to_create => 'alter_create_constraint',
135 constraints_to_drop => 'alter_drop_constraint',
136 indexes_to_create => 'alter_create_index',
137 indexes_to_drop => 'alter_drop_index',
138 fields_to_create => 'add_field',
139 fields_to_alter => 'alter_field',
140 fields_to_rename => 'rename_field',
141 fields_to_drop => 'drop_field',
142 table_options => 'alter_table'
146 if (!$self->no_batch_alters &&
147 (my $batch_alter = $producer_class->can('batch_alter_table')) )
149 # Good - Producer supports batch altering of tables.
150 foreach my $table ( sort keys %{$self->table_diff_hash} ) {
151 my $tar_table = $target_schema->get_table($table)
152 || $source_schema->get_table($table);
154 push @diffs, $batch_alter->($tar_table,
156 $func_map{$_} => $self->table_diff_hash->{$table}{$_}
164 foreach my $table ( sort keys %{$self->table_diff_hash} ) {
165 my $table_diff = $self->table_diff_hash->{$table};
166 for (@diff_hash_keys) {
167 push( @{ $flattened_diffs{ $func_map{$_} } ||= [] }, @{ $table_diff->{$_} } );
172 if (@{$flattened_diffs{$_}}) {
173 my $meth = $producer_class->can($_);
175 $meth ? map { my $sql = $meth->(ref $_ eq 'ARRAY' ? @$_ : $_); $sql ? ("$sql;") : () } @{ $flattened_diffs{$_} }
176 : $self->ignore_missing_methods
177 ? "-- $producer_class cant $_"
178 : die "$producer_class cant $_";
181 } qw/alter_drop_constraint
188 alter_create_constraint
192 if (my @tables = @{ $self->tables_to_create } ) {
193 my $translator = new SQL::Translator(
194 producer_type => $self->output_db,
197 # TODO: sort out options
198 quote_table_names => 0,
199 quote_field_names => 0,
201 my $schema = $translator->schema;
203 $schema->add_table($_) for @tables;
206 # Remove begin/commit here, since we wrap everything in one.
207 grep { $_ !~ /^(?:COMMIT|BEGIN(?: TRANSACTION)?);/ } $producer_class->can('produce')->($translator);
210 if (my @tables_to_drop = @{ $self->{tables_to_drop} || []} ) {
211 my $meth = $producer_class->can('drop_table');
213 push @diffs, $meth ? map( { $meth->($_) } @tables_to_drop )
214 : $self->ignore_missing_methods
215 ? "-- $producer_class cant drop_table"
216 : die "$producer_class cant drop_table";
220 unshift @diffs, "BEGIN TRANSACTION;\n";
221 push @diffs, "\nCOMMIT;\n";
223 @diffs = ("-- No differences found\n\n");
227 if ( $self->target_db !~ /^(?:MySQL|SQLite)$/ ) {
228 unshift(@diffs, "-- Target database @{[$self->target_db]} is untested/unsupported!!!");
230 return join( "\n", "-- Convert schema '$src_name' to '$tar_name':\n", @diffs);
236 sub diff_table_indexes {
237 my ($self, $src_table, $tar_table) = @_;
239 my (%checked_indices);
241 for my $i_tar ( $tar_table->get_indices ) {
242 for my $i_src ( $src_table->get_indices ) {
243 if ( $i_tar->equals($i_src, $self->case_insensitive, $self->ignore_index_names) ) {
244 $checked_indices{$i_src} = 1;
248 push @{$self->table_diff_hash->{$tar_table}{indexes_to_create}}, $i_tar;
252 for my $i_src ( $src_table->get_indices ) {
253 next if !$self->ignore_index_names && $checked_indices{$i_src};
254 for my $i_tar ( $tar_table->get_indices ) {
255 next INDEX_DROP if $i_src->equals($i_tar, $self->case_insensitive, $self->ignore_index_names);
257 push @{$self->table_diff_hash->{$tar_table}{indexes_to_drop}}, $i_src;
262 sub diff_table_constraints {
263 my ($self, $src_table, $tar_table) = @_;
265 my(%checked_constraints);
267 for my $c_tar ( $tar_table->get_constraints ) {
268 for my $c_src ( $src_table->get_constraints ) {
269 if ( $c_tar->equals($c_src, $self->case_insensitive, $self->ignore_constraint_names) ) {
270 $checked_constraints{$c_src} = 1;
271 next CONSTRAINT_CREATE;
274 push @{ $self->table_diff_hash->{$tar_table}{constraints_to_create} }, $c_tar;
279 for my $c_src ( $src_table->get_constraints ) {
280 next if !$self->ignore_constraint_names && $checked_constraints{$c_src};
281 for my $c_tar ( $tar_table->get_constraints ) {
282 next CONSTRAINT_DROP if $c_src->equals($c_tar, $self->case_insensitive, $self->ignore_constraint_names);
285 push @{ $self->table_diff_hash->{$tar_table}{constraints_to_drop} }, $c_src;
290 sub diff_table_fields {
291 my ($self, $src_table, $tar_table) = @_;
293 # List of ones ew've renamed from so we dont drop them
294 my %renamed_source_fields;
296 for my $tar_table_field ( $tar_table->get_fields ) {
297 my $f_tar_name = $tar_table_field->name;
299 if (my $old_name = $tar_table_field->extra->{renamed_from}) {
300 my $src_table_field = $src_table->get_field( $old_name, $self->case_insensitive );
301 die qq#Renamed cant find "@{[$src_table->name]}.$old_name" for renamed column\n# unless $src_table_field;
302 push @{$self->table_diff_hash->{$tar_table}{fields_to_rename} }, [ $src_table_field, $tar_table_field ];
303 $renamed_source_fields{$old_name} = 1;
307 my $src_table_field = $src_table->get_field( $f_tar_name, $self->case_insensitive );
309 unless ( $src_table_field ) {
310 push @{$self->table_diff_hash->{$tar_table}{fields_to_create}}, $tar_table_field;
314 # field exists, something changed. This is a bit complex. Parsers can
315 # normalize types, but only some of them do, so compare the normalized and
316 # parsed types for each field to each other
317 if ( !$tar_table_field->equals($src_table_field, $self->case_insensitive) &&
318 !$tar_table_field->equals($src_table_field->parsed_field, $self->case_insensitive) &&
319 !$tar_table_field->parsed_field->equals($src_table_field, $self->case_insensitive) &&
320 !$tar_table_field->parsed_field->equals($src_table_field->parsed_field, $self->case_insensitive) ) {
322 # Some producers might need src field to diff against
323 push @{$self->table_diff_hash->{$tar_table}{fields_to_alter}}, [ $src_table_field, $tar_table_field ];
329 # Now check to see if any fields from src_table need to be dropped
330 for my $src_table_field ( $src_table->get_fields ) {
331 my $f_src_name = $src_table_field->name;
332 next if $renamed_source_fields{$f_src_name};
334 my $tar_table_field = $tar_table->get_field( $f_src_name, $self->case_insensitive );
336 unless ( $tar_table_field ) {
337 push @{$self->table_diff_hash->{$tar_table}{fields_to_drop}}, $src_table_field;
343 sub diff_table_options {
344 my ($self, $src_table, $tar_table) = @_;
347 # Go through our options
348 my $options_different = 0;
352 for my $tar_table_option_ref ( $tar_table->options ) {
353 my($key_tar, $value_tar) = %{$tar_table_option_ref};
354 for my $src_table_option_ref ( $src_table->options ) {
355 my($key_src, $value_src) = %{$src_table_option_ref};
356 if ( $key_tar eq $key_src ) {
357 if ( defined $value_tar != defined $value_src ) {
358 $options_different = 1;
361 if ( defined $value_tar && $value_tar ne $value_src ) {
362 $options_different = 1;
365 $checkedOptions{$key_tar} = 1;
369 $options_different = 1;
373 # Go through the other table's options
374 unless ( $options_different ) {
375 for my $src_table_option_ref ( $src_table->options ) {
376 my($key, $value) = %{$src_table_option_ref};
377 next if $checkedOptions{$key};
378 $options_different = 1;
383 # If there's a difference, just re-set all the options
384 push @{ $self->table_diff_hash->{$tar_table}{table_options} }, $tar_table
385 if ( $options_different );
394 SQL::Translator::Diff
398 Takes two input SQL::Translator::Schemas (or SQL files) and produces ALTER
399 statments to make them the same
405 use SQL::Translator::Diff;
406 my $sql = SQL::Translator::Diff::schema_diff($source_schema, 'MySQL', $target_schema, 'MySQL', $options_hash)
410 use SQL::Translator::Diff;
411 my $diff = SQL::Translator::Diff->new({
412 output_db => 'MySQL',
413 source_schema => $source_schema,
414 target_schema => $target_schema,
416 })->compute_differences->produce_diff_sql;
422 =item B<ignore_index_names>
424 Match indexes based on types and fields, ignoring name.
426 =item B<ignore_constraint_names>
428 Match constrains based on types, fields and tables, ignoring name.
432 Which producer to use to produce the output.
434 =item B<case_insensitive>
436 Ignore case of table, field, index and constraint names when comparing
438 =item B<no_batch_alters>
440 Produce each alter as a distinct C<ALTER TABLE> statement even if the producer
441 supports the ability to do all alters for a table as one statement.
443 =item B<ignore_missing_methods>
445 If the diff would need a method that is missing from the producer, just emit a
446 comment showing the method is missing, rather than dieing with an error
450 =head1 PRODUCER FUNCTIONS
452 The following producer functions should be implemented for completeness. If
453 any of them are needed for a given diff, but not found, an error will be
458 =item * C<alter_create_constraint($con)>
460 =item * C<alter_drop_constraint($con)>
462 =item * C<alter_create_index($idx)>
464 =item * C<alter_drop_index($idx)>
466 =item * C<add_field($fld)>
468 =item * C<alter_field($old_fld, $new_fld)>
470 =item * C<rename_field($old_fld, $new_fld)>
472 =item * C<drop_field($fld)>
474 =item * C<alter_table($table)>
476 =item * C<drop_table($table)>
478 =item * C<batch_alter_table($table, $hash)> (optional)
482 If the producer supports C<batch_alter_table>, it will be called with the
483 table to alter and a hash, the keys of which will be the method names listed
484 above; values will be arrays of fields or constraints to operate on. In the
485 case of the field functions that take two arguments this will appear as a hash.
487 I.e. the hash might look something like the following:
490 alter_create_constraint => [ $constraint1, $constraint2 ],
491 add_field => [ $field ],
492 alter_field => [ [$old_field, $new_field] ]
497 Original Author(s) unknown.
499 Refactor and more comprehensive tests by Ash Berlin C<< ash@cpan.org >>.
501 Redevelopment sponsored by Takkle Inc.