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);
82 $producer_class->$preprocess($target_schema);
85 my @tar_tables = sort { $a->name cmp $b->name } $target_schema->get_tables;
86 ## do original/source tables exist in target?
87 for my $tar_table ( @tar_tables ) {
88 my $tar_table_name = $tar_table->name;
89 my $src_table = $source_schema->get_table( $tar_table_name, $self->case_insensitive );
91 unless ( $src_table ) {
93 ## add table(s) later.
94 push @{$self->tables_to_create}, $tar_table;
98 $self->table_diff_hash->{$tar_table_name} = {
99 map {$_ => [] } @diff_hash_keys
102 $self->diff_table_options($src_table, $tar_table);
104 ## Compare fields, their types, defaults, sizes etc etc
105 $self->diff_table_fields($src_table, $tar_table);
107 $self->diff_table_indexes($src_table, $tar_table);
108 $self->diff_table_constraints($src_table, $tar_table);
110 } # end of target_schema->get_tables loop
112 for my $src_table ( $source_schema->get_tables ) {
113 my $src_table_name = $src_table->name;
114 my $tar_table = $target_schema->get_table( $src_table_name, $self->case_insensitive );
116 unless ( $tar_table ) {
117 $self->table_diff_hash->{$src_table_name} = {
118 map {$_ => [] } @diff_hash_keys
121 push @{ $self->tables_to_drop}, $src_table;
129 sub produce_diff_sql {
132 my $target_schema = $self->target_schema;
133 my $source_schema = $self->source_schema;
134 my $tar_name = $target_schema->name;
135 my $src_name = $source_schema->name;
137 my $producer_class = "SQL::Translator::Producer::@{[$self->output_db]}";
138 eval "require $producer_class";
141 # Map of name we store under => producer method name
143 constraints_to_create => 'alter_create_constraint',
144 constraints_to_drop => 'alter_drop_constraint',
145 indexes_to_create => 'alter_create_index',
146 indexes_to_drop => 'alter_drop_index',
147 fields_to_create => 'add_field',
148 fields_to_alter => 'alter_field',
149 fields_to_rename => 'rename_field',
150 fields_to_drop => 'drop_field',
151 table_options => 'alter_table'
155 if (!$self->no_batch_alters &&
156 (my $batch_alter = $producer_class->can('batch_alter_table')) )
158 # Good - Producer supports batch altering of tables.
159 foreach my $table ( sort keys %{$self->table_diff_hash} ) {
160 my $tar_table = $target_schema->get_table($table)
161 || $source_schema->get_table($table);
163 push @diffs, $batch_alter->($tar_table,
165 $func_map{$_} => $self->table_diff_hash->{$table}{$_}
173 foreach my $table ( sort keys %{$self->table_diff_hash} ) {
174 my $table_diff = $self->table_diff_hash->{$table};
175 for (@diff_hash_keys) {
176 push( @{ $flattened_diffs{ $func_map{$_} } ||= [] }, @{ $table_diff->{$_} } );
181 if (@{$flattened_diffs{$_}}) {
182 my $meth = $producer_class->can($_);
184 $meth ? map { my $sql = $meth->(ref $_ eq 'ARRAY' ? @$_ : $_); $sql ? ("$sql;") : () } @{ $flattened_diffs{$_} }
185 : $self->ignore_missing_methods
186 ? "-- $producer_class cant $_"
187 : die "$producer_class cant $_";
190 } qw/alter_drop_constraint
197 alter_create_constraint
201 if (my @tables = @{ $self->tables_to_create } ) {
202 my $translator = new SQL::Translator(
203 producer_type => $self->output_db,
206 # TODO: sort out options
207 quote_table_names => 0,
208 quote_field_names => 0,
210 my $schema = $translator->schema;
212 $schema->add_table($_) for @tables;
215 # Remove begin/commit here, since we wrap everything in one.
216 grep { $_ !~ /^(?:COMMIT|BEGIN(?: TRANSACTION)?);/ } $producer_class->can('produce')->($translator);
219 if (my @tables_to_drop = @{ $self->{tables_to_drop} || []} ) {
220 my $meth = $producer_class->can('drop_table');
222 push @diffs, $meth ? map( { $meth->($_) } @tables_to_drop )
223 : $self->ignore_missing_methods
224 ? "-- $producer_class cant drop_table"
225 : die "$producer_class cant drop_table";
229 unshift @diffs, "BEGIN TRANSACTION;\n";
230 push @diffs, "\nCOMMIT;\n";
232 @diffs = ("-- No differences found\n\n");
236 if ( $self->target_db !~ /^(?:MySQL|SQLite)$/ ) {
237 unshift(@diffs, "-- Target database @{[$self->target_db]} is untested/unsupported!!!");
239 return join( "\n", "-- Convert schema '$src_name' to '$tar_name':\n", @diffs);
245 sub diff_table_indexes {
246 my ($self, $src_table, $tar_table) = @_;
248 my (%checked_indices);
250 for my $i_tar ( $tar_table->get_indices ) {
251 for my $i_src ( $src_table->get_indices ) {
252 if ( $i_tar->equals($i_src, $self->case_insensitive, $self->ignore_index_names) ) {
253 $checked_indices{$i_src} = 1;
257 push @{$self->table_diff_hash->{$tar_table}{indexes_to_create}}, $i_tar;
261 for my $i_src ( $src_table->get_indices ) {
262 next if !$self->ignore_index_names && $checked_indices{$i_src};
263 for my $i_tar ( $tar_table->get_indices ) {
264 next INDEX_DROP if $i_src->equals($i_tar, $self->case_insensitive, $self->ignore_index_names);
266 push @{$self->table_diff_hash->{$tar_table}{indexes_to_drop}}, $i_src;
271 sub diff_table_constraints {
272 my ($self, $src_table, $tar_table) = @_;
274 my(%checked_constraints);
276 for my $c_tar ( $tar_table->get_constraints ) {
277 for my $c_src ( $src_table->get_constraints ) {
278 if ( $c_tar->equals($c_src, $self->case_insensitive, $self->ignore_constraint_names) ) {
279 $checked_constraints{$c_src} = 1;
280 next CONSTRAINT_CREATE;
283 push @{ $self->table_diff_hash->{$tar_table}{constraints_to_create} }, $c_tar;
288 for my $c_src ( $src_table->get_constraints ) {
289 next if !$self->ignore_constraint_names && $checked_constraints{$c_src};
290 for my $c_tar ( $tar_table->get_constraints ) {
291 next CONSTRAINT_DROP if $c_src->equals($c_tar, $self->case_insensitive, $self->ignore_constraint_names);
294 push @{ $self->table_diff_hash->{$tar_table}{constraints_to_drop} }, $c_src;
299 sub diff_table_fields {
300 my ($self, $src_table, $tar_table) = @_;
302 # List of ones ew've renamed from so we dont drop them
303 my %renamed_source_fields;
305 for my $tar_table_field ( $tar_table->get_fields ) {
306 my $f_tar_name = $tar_table_field->name;
308 if (my $old_name = $tar_table_field->extra->{renamed_from}) {
309 my $src_table_field = $src_table->get_field( $old_name, $self->case_insensitive );
310 die qq#Renamed cant find "@{[$src_table->name]}.$old_name" for renamed column\n# unless $src_table_field;
311 push @{$self->table_diff_hash->{$tar_table}{fields_to_rename} }, [ $src_table_field, $tar_table_field ];
312 $renamed_source_fields{$old_name} = 1;
316 my $src_table_field = $src_table->get_field( $f_tar_name, $self->case_insensitive );
318 unless ( $src_table_field ) {
319 push @{$self->table_diff_hash->{$tar_table}{fields_to_create}}, $tar_table_field;
323 # field exists, something changed. This is a bit complex. Parsers can
324 # normalize types, but only some of them do, so compare the normalized and
325 # parsed types for each field to each other
326 if ( !$tar_table_field->equals($src_table_field, $self->case_insensitive) &&
327 !$tar_table_field->equals($src_table_field->parsed_field, $self->case_insensitive) &&
328 !$tar_table_field->parsed_field->equals($src_table_field, $self->case_insensitive) &&
329 !$tar_table_field->parsed_field->equals($src_table_field->parsed_field, $self->case_insensitive) ) {
331 # Some producers might need src field to diff against
332 push @{$self->table_diff_hash->{$tar_table}{fields_to_alter}}, [ $src_table_field, $tar_table_field ];
338 # Now check to see if any fields from src_table need to be dropped
339 for my $src_table_field ( $src_table->get_fields ) {
340 my $f_src_name = $src_table_field->name;
341 next if $renamed_source_fields{$f_src_name};
343 my $tar_table_field = $tar_table->get_field( $f_src_name, $self->case_insensitive );
345 unless ( $tar_table_field ) {
346 push @{$self->table_diff_hash->{$tar_table}{fields_to_drop}}, $src_table_field;
352 sub diff_table_options {
353 my ($self, $src_table, $tar_table) = @_;
356 # If there's a difference, just re-set all the options
357 push @{ $self->table_diff_hash->{$tar_table}{table_options} }, $tar_table
358 unless $src_table->_compare_objects( scalar $src_table->options, scalar $tar_table->options );
367 SQL::Translator::Diff
371 Takes two input SQL::Translator::Schemas (or SQL files) and produces ALTER
372 statments to make them the same
378 use SQL::Translator::Diff;
379 my $sql = SQL::Translator::Diff::schema_diff($source_schema, 'MySQL', $target_schema, 'MySQL', $options_hash)
383 use SQL::Translator::Diff;
384 my $diff = SQL::Translator::Diff->new({
385 output_db => 'MySQL',
386 source_schema => $source_schema,
387 target_schema => $target_schema,
389 })->compute_differences->produce_diff_sql;
395 =item B<ignore_index_names>
397 Match indexes based on types and fields, ignoring name.
399 =item B<ignore_constraint_names>
401 Match constrains based on types, fields and tables, ignoring name.
405 Which producer to use to produce the output.
407 =item B<case_insensitive>
409 Ignore case of table, field, index and constraint names when comparing
411 =item B<no_batch_alters>
413 Produce each alter as a distinct C<ALTER TABLE> statement even if the producer
414 supports the ability to do all alters for a table as one statement.
416 =item B<ignore_missing_methods>
418 If the diff would need a method that is missing from the producer, just emit a
419 comment showing the method is missing, rather than dieing with an error
423 =head1 PRODUCER FUNCTIONS
425 The following producer functions should be implemented for completeness. If
426 any of them are needed for a given diff, but not found, an error will be
431 =item * C<alter_create_constraint($con)>
433 =item * C<alter_drop_constraint($con)>
435 =item * C<alter_create_index($idx)>
437 =item * C<alter_drop_index($idx)>
439 =item * C<add_field($fld)>
441 =item * C<alter_field($old_fld, $new_fld)>
443 =item * C<rename_field($old_fld, $new_fld)>
445 =item * C<drop_field($fld)>
447 =item * C<alter_table($table)>
449 =item * C<drop_table($table)>
451 =item * C<batch_alter_table($table, $hash)> (optional)
455 If the producer supports C<batch_alter_table>, it will be called with the
456 table to alter and a hash, the keys of which will be the method names listed
457 above; values will be arrays of fields or constraints to operate on. In the
458 case of the field functions that take two arguments this will appear as a hash.
460 I.e. the hash might look something like the following:
463 alter_create_constraint => [ $constraint1, $constraint2 ],
464 add_field => [ $field ],
465 alter_field => [ [$old_field, $new_field] ]
470 Original Author(s) unknown.
472 Refactor and more comprehensive tests by Ash Berlin C<< ash@cpan.org >>.
474 Redevelopment sponsored by Takkle Inc.