1SQL::Translator::Diff(3U)ser Contributed Perl DocumentatiSoQnL::Translator::Diff(3)
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NAME

6       SQL::Translator::Diff
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DESCRIPTION

9       Takes two input SQL::Translator::Schemas (or SQL files) and produces
10       ALTER statments to make them the same
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SNYOPSIS

13       Simplest usage:
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15        use SQL::Translator::Diff;
16        my $sql = SQL::Translator::Diff::schema_diff($source_schema, 'MySQL', $target_schema, 'MySQL', $options_hash)
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18       OO usage:
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20        use SQL::Translator::Diff;
21        my $diff = SQL::Translator::Diff->new({
22          output_db     => 'MySQL',
23          source_schema => $source_schema,
24          target_schema => $target_schema,
25          %$options_hash,
26        })->compute_differences->produce_diff_sql;
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OPTIONS

29       ignore_index_names
30           Match indexes based on types and fields, ignoring name.
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32       ignore_constraint_names
33           Match constrains based on types, fields and tables, ignoring name.
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35       output_db
36           Which producer to use to produce the output.
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38       case_insensitive
39           Ignore case of table, field, index and constraint names when
40           comparing
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42       no_batch_alters
43           Produce each alter as a distinct "ALTER TABLE" statement even if
44           the producer supports the ability to do all alters for a table as
45           one statement.
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47       ignore_missing_methods
48           If the diff would need a method that is missing from the producer,
49           just emit a comment showing the method is missing, rather than
50           dieing with an error
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PRODUCER FUNCTIONS

53       The following producer functions should be implemented for
54       completeness. If any of them are needed for a given diff, but not
55       found, an error will be thrown.
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57       ·   "alter_create_constraint($con)"
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59       ·   "alter_drop_constraint($con)"
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61       ·   "alter_create_index($idx)"
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63       ·   "alter_drop_index($idx)"
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65       ·   "add_field($fld)"
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67       ·   "alter_field($old_fld, $new_fld)"
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69       ·   "rename_field($old_fld, $new_fld)"
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71       ·   "drop_field($fld)"
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73       ·   "alter_table($table)"
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75       ·   "drop_table($table)"
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77       ·   "rename_table($old_table, $new_table)" (optional)
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79       ·   "batch_alter_table($table, $hash)" (optional)
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81           If the producer supports "batch_alter_table", it will be called
82           with the table to alter and a hash, the keys of which will be the
83           method names listed above; values will be arrays of fields or
84           constraints to operate on. In the case of the field functions that
85           take two arguments this will appear as a hash.
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87           I.e. the hash might look something like the following:
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89            {
90              alter_create_constraint => [ $constraint1, $constraint2 ],
91              add_field   => [ $field ],
92              alter_field => [ [$old_field, $new_field] ]
93            }
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95       ·   "preprocess_schema($class, $schema)" (optional)
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97           "preprocess_schema" is called by the Diff code to allow the
98           producer to normalize any data it needs to first. For example, the
99           MySQL producer uses this method to ensure that FK contraint names
100           are unique.
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102           Basicaly any changes that need to be made to produce the SQL file
103           for the schema should be done here, so that a diff between a parsed
104           SQL file and (say) a parsed DBIx::Class::Schema object will be
105           sane.
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107           (As an aside, DBIx::Class, for instance, uses the presence of a
108           "preprocess_schema" function on the producer to know that it can
109           diff between the previous SQL file and its own internal
110           representation. Without this method on th producer it will diff the
111           two SQL files which is slower, but known to work better on old-
112           style producers.)
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AUTHOR

115       Original Author(s) unknown.
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117       Refactor/re-write and more comprehensive tests by Ash Berlin
118       "ash@cpan.org".
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120       Redevelopment sponsored by Takkle Inc.
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124perl v5.12.0                      2010-02-14          SQL::Translator::Diff(3)