Commit | Line | Data |
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1 | package SQL::Translator::Diff; |
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2 | |
3 | |
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4 | ## SQLT schema diffing code |
5 | use strict; |
6 | use warnings; |
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7 | |
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8 | use Data::Dumper; |
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9 | use SQL::Translator::Schema::Constants; |
10 | |
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11 | use base 'Class::Accessor::Fast'; |
12 | |
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 |
18 | /); |
19 | |
20 | my @diff_arrays = qw/ |
21 | tables_to_drop |
22 | tables_to_create |
23 | /; |
24 | |
25 | my @diff_hash_keys = qw/ |
26 | constraints_to_create |
27 | constraints_to_drop |
28 | indexes_to_create |
29 | indexes_to_drop |
30 | fields_to_create |
31 | fields_to_alter |
32 | fields_to_rename |
33 | fields_to_drop |
34 | table_options |
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35 | table_renamed_from |
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36 | /; |
37 | |
38 | __PACKAGE__->mk_accessors(@diff_arrays, 'table_diff_hash'); |
39 | |
40 | sub schema_diff { |
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41 | # use Data::Dumper; |
42 | ## we are getting instructions on how to turn the source into the target |
43 | ## source == original, target == new (hmm, if I need to comment this, should I rename the vars again ??) |
44 | ## _schema isa SQL::Translator::Schema |
45 | ## _db is the name of the producer/db it came out of/into |
46 | ## results are formatted to the source preferences |
47 | |
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48 | my ($source_schema, $source_db, $target_schema, $target_db, $options) = @_; |
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49 | $options ||= {}; |
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50 | |
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51 | my $obj = SQL::Translator::Diff->new( { |
52 | %$options, |
53 | source_schema => $source_schema, |
54 | source_db => $source_db, |
55 | target_schema => $target_schema, |
56 | target_db => $target_db |
57 | } ); |
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58 | |
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59 | $obj->compute_differences->produce_diff_sql; |
60 | } |
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61 | |
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62 | sub new { |
63 | my ($class, $values) = @_; |
64 | $values->{$_} ||= [] foreach @diff_arrays; |
65 | $values->{table_diff_hash} = {}; |
66 | |
67 | $values->{output_db} ||= $values->{source_db}; |
68 | return $class->SUPER::new($values); |
69 | } |
70 | |
71 | sub compute_differences { |
72 | my ($self) = @_; |
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73 | |
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74 | my $target_schema = $self->target_schema; |
75 | my $source_schema = $self->source_schema; |
76 | |
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77 | my $producer_class = "SQL::Translator::Producer::@{[$self->output_db]}"; |
78 | eval "require $producer_class"; |
79 | die $@ if $@; |
80 | |
81 | if (my $preprocess = $producer_class->can('preprocess_schema')) { |
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82 | $preprocess->($source_schema); |
83 | $preprocess->($target_schema); |
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84 | } |
85 | |
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86 | my %src_tables_checked = (); |
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87 | my @tar_tables = sort { $a->name cmp $b->name } $target_schema->get_tables; |
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88 | ## do original/source tables exist in target? |
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89 | for my $tar_table ( @tar_tables ) { |
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90 | my $tar_table_name = $tar_table->name; |
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91 | |
92 | my $src_table; |
93 | |
94 | $self->table_diff_hash->{$tar_table_name} = { |
95 | map {$_ => [] } @diff_hash_keys |
96 | }; |
97 | |
98 | if (my $old_name = $tar_table->extra('renamed_from')) { |
99 | $src_table = $source_schema->get_table( $old_name, $self->case_insensitive ); |
100 | if ($src_table) { |
101 | $self->table_diff_hash->{$tar_table_name}{table_renamed_from} = [ [$src_table, $tar_table] ]; |
102 | } else { |
103 | delete $tar_table->extra->{renamed_from}; |
104 | warn qq#Renamed table can't find old table "$old_name" for renamed table\n#; |
105 | } |
106 | } else { |
107 | $src_table = $source_schema->get_table( $tar_table_name, $self->case_insensitive ); |
108 | } |
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109 | |
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110 | unless ( $src_table ) { |
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111 | ## table is new |
112 | ## add table(s) later. |
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113 | push @{$self->tables_to_create}, $tar_table; |
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114 | next; |
115 | } |
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116 | |
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117 | my $src_table_name = $src_table->name; |
118 | $src_table_name = lc $src_table_name if $self->case_insensitive; |
119 | $src_tables_checked{$src_table_name} = 1; |
120 | |
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121 | |
122 | $self->diff_table_options($src_table, $tar_table); |
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123 | |
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124 | ## Compare fields, their types, defaults, sizes etc etc |
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125 | $self->diff_table_fields($src_table, $tar_table); |
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126 | |
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127 | $self->diff_table_indexes($src_table, $tar_table); |
128 | $self->diff_table_constraints($src_table, $tar_table); |
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129 | |
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130 | } # end of target_schema->get_tables loop |
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131 | |
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132 | for my $src_table ( $source_schema->get_tables ) { |
133 | my $src_table_name = $src_table->name; |
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134 | |
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135 | $src_table_name = lc $src_table_name if $self->case_insensitive; |
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136 | |
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137 | push @{ $self->tables_to_drop}, $src_table |
138 | unless $src_tables_checked{$src_table_name}; |
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139 | } |
140 | |
141 | return $self; |
142 | } |
143 | |
144 | sub produce_diff_sql { |
145 | my ($self) = @_; |
146 | |
147 | my $target_schema = $self->target_schema; |
148 | my $source_schema = $self->source_schema; |
149 | my $tar_name = $target_schema->name; |
150 | my $src_name = $source_schema->name; |
151 | |
152 | my $producer_class = "SQL::Translator::Producer::@{[$self->output_db]}"; |
153 | eval "require $producer_class"; |
154 | die $@ if $@; |
155 | |
156 | # Map of name we store under => producer method name |
157 | my %func_map = ( |
158 | constraints_to_create => 'alter_create_constraint', |
159 | constraints_to_drop => 'alter_drop_constraint', |
160 | indexes_to_create => 'alter_create_index', |
161 | indexes_to_drop => 'alter_drop_index', |
162 | fields_to_create => 'add_field', |
163 | fields_to_alter => 'alter_field', |
164 | fields_to_rename => 'rename_field', |
165 | fields_to_drop => 'drop_field', |
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166 | table_options => 'alter_table', |
167 | table_renamed_from => 'rename_table', |
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168 | ); |
169 | my @diffs; |
170 | |
171 | if (!$self->no_batch_alters && |
172 | (my $batch_alter = $producer_class->can('batch_alter_table')) ) |
173 | { |
174 | # Good - Producer supports batch altering of tables. |
175 | foreach my $table ( sort keys %{$self->table_diff_hash} ) { |
176 | my $tar_table = $target_schema->get_table($table) |
177 | || $source_schema->get_table($table); |
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178 | |
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179 | push @diffs, $batch_alter->($tar_table, |
180 | { map { |
181 | $func_map{$_} => $self->table_diff_hash->{$table}{$_} |
182 | } keys %func_map |
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183 | } |
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184 | ); |
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185 | } |
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186 | } else { |
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187 | |
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188 | # If we have any table renames we need to do those first; |
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189 | my %flattened_diffs; |
190 | foreach my $table ( sort keys %{$self->table_diff_hash} ) { |
191 | my $table_diff = $self->table_diff_hash->{$table}; |
192 | for (@diff_hash_keys) { |
193 | push( @{ $flattened_diffs{ $func_map{$_} } ||= [] }, @{ $table_diff->{$_} } ); |
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194 | } |
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195 | } |
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196 | |
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197 | push @diffs, map( { |
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198 | if (@{ $flattened_diffs{$_} || [] }) { |
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199 | my $meth = $producer_class->can($_); |
200 | |
201 | $meth ? map { my $sql = $meth->(ref $_ eq 'ARRAY' ? @$_ : $_); $sql ? ("$sql;") : () } @{ $flattened_diffs{$_} } |
202 | : $self->ignore_missing_methods |
203 | ? "-- $producer_class cant $_" |
204 | : die "$producer_class cant $_"; |
205 | } else { () } |
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206 | |
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207 | } qw/rename_table |
208 | alter_drop_constraint |
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209 | alter_drop_index |
210 | drop_field |
211 | add_field |
212 | alter_field |
213 | rename_field |
214 | alter_create_index |
215 | alter_create_constraint |
216 | alter_table/), |
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217 | } |
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218 | |
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219 | if (my @tables = @{ $self->tables_to_create } ) { |
220 | my $translator = new SQL::Translator( |
221 | producer_type => $self->output_db, |
222 | add_drop_table => 0, |
223 | no_comments => 1, |
224 | # TODO: sort out options |
225 | quote_table_names => 0, |
226 | quote_field_names => 0, |
227 | ); |
228 | my $schema = $translator->schema; |
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229 | |
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230 | $schema->add_table($_) for @tables; |
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231 | |
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232 | unshift @diffs, |
233 | # Remove begin/commit here, since we wrap everything in one. |
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234 | grep { $_ !~ /^(?:COMMIT|START(?: TRANSACTION)?|BEGIN(?: TRANSACTION)?);/ } $producer_class->can('produce')->($translator); |
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235 | } |
236 | |
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237 | if (my @tables_to_drop = @{ $self->{tables_to_drop} || []} ) { |
238 | my $meth = $producer_class->can('drop_table'); |
239 | |
240 | push @diffs, $meth ? map( { $meth->($_) } @tables_to_drop ) |
241 | : $self->ignore_missing_methods |
242 | ? "-- $producer_class cant drop_table" |
243 | : die "$producer_class cant drop_table"; |
244 | } |
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245 | |
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246 | if (@diffs) { |
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247 | unshift @diffs, "BEGIN;\n"; |
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248 | push @diffs, "\nCOMMIT;\n"; |
249 | } else { |
250 | @diffs = ("-- No differences found\n\n"); |
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251 | } |
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252 | |
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253 | if ( @diffs ) { |
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254 | if ( $self->target_db !~ /^(?:MySQL|SQLite)$/ ) { |
255 | unshift(@diffs, "-- Target database @{[$self->target_db]} is untested/unsupported!!!"); |
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256 | } |
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257 | return join( "\n", "-- Convert schema '$src_name' to '$tar_name':\n", @diffs); |
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258 | } |
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259 | return undef; |
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260 | |
261 | } |
262 | |
263 | sub diff_table_indexes { |
264 | my ($self, $src_table, $tar_table) = @_; |
265 | |
266 | my (%checked_indices); |
267 | INDEX_CREATE: |
268 | for my $i_tar ( $tar_table->get_indices ) { |
269 | for my $i_src ( $src_table->get_indices ) { |
270 | if ( $i_tar->equals($i_src, $self->case_insensitive, $self->ignore_index_names) ) { |
271 | $checked_indices{$i_src} = 1; |
272 | next INDEX_CREATE; |
273 | } |
274 | } |
275 | push @{$self->table_diff_hash->{$tar_table}{indexes_to_create}}, $i_tar; |
276 | } |
277 | |
278 | INDEX_DROP: |
279 | for my $i_src ( $src_table->get_indices ) { |
280 | next if !$self->ignore_index_names && $checked_indices{$i_src}; |
281 | for my $i_tar ( $tar_table->get_indices ) { |
282 | next INDEX_DROP if $i_src->equals($i_tar, $self->case_insensitive, $self->ignore_index_names); |
283 | } |
284 | push @{$self->table_diff_hash->{$tar_table}{indexes_to_drop}}, $i_src; |
285 | } |
286 | } |
287 | |
288 | |
289 | sub diff_table_constraints { |
290 | my ($self, $src_table, $tar_table) = @_; |
291 | |
292 | my(%checked_constraints); |
293 | CONSTRAINT_CREATE: |
294 | for my $c_tar ( $tar_table->get_constraints ) { |
295 | for my $c_src ( $src_table->get_constraints ) { |
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296 | |
297 | # This is a bit of a hack - needed for renaming tables to work |
298 | local $c_src->{table} = $tar_table; |
299 | |
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300 | if ( $c_tar->equals($c_src, $self->case_insensitive, $self->ignore_constraint_names) ) { |
301 | $checked_constraints{$c_src} = 1; |
302 | next CONSTRAINT_CREATE; |
303 | } |
304 | } |
305 | push @{ $self->table_diff_hash->{$tar_table}{constraints_to_create} }, $c_tar; |
306 | } |
307 | |
308 | |
309 | CONSTRAINT_DROP: |
310 | for my $c_src ( $src_table->get_constraints ) { |
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311 | |
312 | # This is a bit of a hack - needed for renaming tables to work |
313 | local $c_src->{table} = $tar_table; |
314 | |
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315 | next if !$self->ignore_constraint_names && $checked_constraints{$c_src}; |
316 | for my $c_tar ( $tar_table->get_constraints ) { |
317 | next CONSTRAINT_DROP if $c_src->equals($c_tar, $self->case_insensitive, $self->ignore_constraint_names); |
318 | } |
319 | |
320 | push @{ $self->table_diff_hash->{$tar_table}{constraints_to_drop} }, $c_src; |
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321 | } |
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322 | |
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323 | } |
324 | |
325 | sub diff_table_fields { |
326 | my ($self, $src_table, $tar_table) = @_; |
327 | |
328 | # List of ones ew've renamed from so we dont drop them |
329 | my %renamed_source_fields; |
330 | |
331 | for my $tar_table_field ( $tar_table->get_fields ) { |
332 | my $f_tar_name = $tar_table_field->name; |
333 | |
334 | if (my $old_name = $tar_table_field->extra->{renamed_from}) { |
335 | my $src_table_field = $src_table->get_field( $old_name, $self->case_insensitive ); |
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336 | unless ($src_table_field) { |
337 | warn qq#Renamed column can't find old column "@{[$src_table->name]}.$old_name" for renamed column\n#; |
338 | delete $tar_table_field->extra->{renamed_from}; |
339 | } else { |
340 | push @{$self->table_diff_hash->{$tar_table}{fields_to_rename} }, [ $src_table_field, $tar_table_field ]; |
341 | $renamed_source_fields{$old_name} = 1; |
342 | next; |
343 | } |
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344 | } |
345 | |
346 | my $src_table_field = $src_table->get_field( $f_tar_name, $self->case_insensitive ); |
347 | |
348 | unless ( $src_table_field ) { |
349 | push @{$self->table_diff_hash->{$tar_table}{fields_to_create}}, $tar_table_field; |
350 | next; |
351 | } |
352 | |
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353 | # field exists, something changed. This is a bit complex. Parsers can |
354 | # normalize types, but only some of them do, so compare the normalized and |
355 | # parsed types for each field to each other |
356 | if ( !$tar_table_field->equals($src_table_field, $self->case_insensitive) && |
357 | !$tar_table_field->equals($src_table_field->parsed_field, $self->case_insensitive) && |
358 | !$tar_table_field->parsed_field->equals($src_table_field, $self->case_insensitive) && |
359 | !$tar_table_field->parsed_field->equals($src_table_field->parsed_field, $self->case_insensitive) ) { |
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360 | |
361 | # Some producers might need src field to diff against |
362 | push @{$self->table_diff_hash->{$tar_table}{fields_to_alter}}, [ $src_table_field, $tar_table_field ]; |
363 | next; |
364 | } |
365 | } |
366 | |
367 | |
368 | # Now check to see if any fields from src_table need to be dropped |
369 | for my $src_table_field ( $src_table->get_fields ) { |
370 | my $f_src_name = $src_table_field->name; |
371 | next if $renamed_source_fields{$f_src_name}; |
372 | |
373 | my $tar_table_field = $tar_table->get_field( $f_src_name, $self->case_insensitive ); |
374 | |
375 | unless ( $tar_table_field ) { |
376 | push @{$self->table_diff_hash->{$tar_table}{fields_to_drop}}, $src_table_field; |
377 | next; |
378 | } |
379 | } |
380 | } |
381 | |
382 | sub diff_table_options { |
383 | my ($self, $src_table, $tar_table) = @_; |
384 | |
385 | |
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386 | # If there's a difference, just re-set all the options |
387 | push @{ $self->table_diff_hash->{$tar_table}{table_options} }, $tar_table |
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388 | unless $src_table->_compare_objects( scalar $src_table->options, scalar $tar_table->options ); |
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389 | } |
390 | |
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391 | 1; |
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392 | |
393 | __END__ |
394 | |
395 | =head1 NAME |
396 | |
397 | SQL::Translator::Diff |
398 | |
399 | =head1 DESCRIPTION |
400 | |
401 | Takes two input SQL::Translator::Schemas (or SQL files) and produces ALTER |
402 | statments to make them the same |
403 | |
404 | =head1 SNYOPSIS |
405 | |
406 | Simplest usage: |
407 | |
408 | use SQL::Translator::Diff; |
409 | my $sql = SQL::Translator::Diff::schema_diff($source_schema, 'MySQL', $target_schema, 'MySQL', $options_hash) |
410 | |
411 | OO usage: |
412 | |
413 | use SQL::Translator::Diff; |
414 | my $diff = SQL::Translator::Diff->new({ |
415 | output_db => 'MySQL', |
416 | source_schema => $source_schema, |
417 | target_schema => $target_schema, |
418 | %$options_hash, |
419 | })->compute_differences->produce_diff_sql; |
420 | |
421 | =head1 OPTIONS |
422 | |
423 | =over |
424 | |
425 | =item B<ignore_index_names> |
426 | |
427 | Match indexes based on types and fields, ignoring name. |
428 | |
429 | =item B<ignore_constraint_names> |
430 | |
431 | Match constrains based on types, fields and tables, ignoring name. |
432 | |
433 | =item B<output_db> |
434 | |
435 | Which producer to use to produce the output. |
436 | |
437 | =item B<case_insensitive> |
438 | |
439 | Ignore case of table, field, index and constraint names when comparing |
440 | |
441 | =item B<no_batch_alters> |
442 | |
443 | Produce each alter as a distinct C<ALTER TABLE> statement even if the producer |
444 | supports the ability to do all alters for a table as one statement. |
445 | |
446 | =item B<ignore_missing_methods> |
447 | |
448 | If the diff would need a method that is missing from the producer, just emit a |
449 | comment showing the method is missing, rather than dieing with an error |
450 | |
451 | =back |
452 | |
453 | =head1 PRODUCER FUNCTIONS |
454 | |
455 | The following producer functions should be implemented for completeness. If |
456 | any of them are needed for a given diff, but not found, an error will be |
457 | thrown. |
458 | |
459 | =over |
460 | |
461 | =item * C<alter_create_constraint($con)> |
462 | |
463 | =item * C<alter_drop_constraint($con)> |
464 | |
465 | =item * C<alter_create_index($idx)> |
466 | |
467 | =item * C<alter_drop_index($idx)> |
468 | |
469 | =item * C<add_field($fld)> |
470 | |
471 | =item * C<alter_field($old_fld, $new_fld)> |
472 | |
473 | =item * C<rename_field($old_fld, $new_fld)> |
474 | |
475 | =item * C<drop_field($fld)> |
476 | |
477 | =item * C<alter_table($table)> |
478 | |
479 | =item * C<drop_table($table)> |
480 | |
46bf5655 |
481 | =item * C<rename_table($old_table, $new_table)> (optional) |
482 | |
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483 | =item * C<batch_alter_table($table, $hash)> (optional) |
484 | |
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485 | If the producer supports C<batch_alter_table>, it will be called with the |
486 | table to alter and a hash, the keys of which will be the method names listed |
487 | above; values will be arrays of fields or constraints to operate on. In the |
488 | case of the field functions that take two arguments this will appear as a hash. |
489 | |
490 | I.e. the hash might look something like the following: |
491 | |
492 | { |
493 | alter_create_constraint => [ $constraint1, $constraint2 ], |
494 | add_field => [ $field ], |
495 | alter_field => [ [$old_field, $new_field] ] |
496 | } |
497 | |
934e1b39 |
498 | |
499 | =item * C<preprocess_schema($class, $schema)> (optional) |
500 | |
501 | C<preprocess_schema> is called by the Diff code to allow the producer to |
502 | normalize any data it needs to first. For example, the MySQL producer uses |
503 | this method to ensure that FK contraint names are unique. |
504 | |
505 | Basicaly any changes that need to be made to produce the SQL file for the |
506 | schema should be done here, so that a diff between a parsed SQL file and (say) |
507 | a parsed DBIx::Class::Schema object will be sane. |
508 | |
509 | (As an aside, DBIx::Class, for instance, uses the presence of a |
510 | C<preprocess_schema> function on the producer to know that it can diff between |
511 | the previous SQL file and its own internal representation. Without this method |
512 | on th producer it will diff the two SQL files which is slower, but known to |
513 | work better on old-style producers.) |
514 | |
515 | =back |
516 | |
517 | |
4d438549 |
518 | =head1 AUTHOR |
519 | |
520 | Original Author(s) unknown. |
521 | |
934e1b39 |
522 | Refactor/re-write and more comprehensive tests by Ash Berlin C<< ash@cpan.org >>. |
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523 | |
524 | Redevelopment sponsored by Takkle Inc. |
525 | |
526 | =cut |