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Added that the MySQL adapter should map integer to either smallint, i…
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…nt, or bigint depending on the :limit just like PostgreSQL [DHH]
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David Heinemeier Hansson committed Apr 25, 2008
1 parent 1959db3 commit a375465
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2 changes: 2 additions & 0 deletions activerecord/CHANGELOG
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@@ -1,5 +1,7 @@
*SVN*

* Added that the MySQL adapter should map integer to either smallint, int, or bigint depending on the :limit just like PostgreSQL [DHH]

* Change validates_uniqueness_of :case_sensitive option default back to true (from [9160]). Love your database columns, don't LOWER them. [rick]

* Add support for interleaving migrations by storing which migrations have run in the new schema_migrations table. Closes #11493 [jordi]
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16 changes: 16 additions & 0 deletions activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
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Expand Up @@ -463,6 +463,22 @@ def rename_column(table_name, column_name, new_column_name) #:nodoc:
execute "ALTER TABLE #{quote_table_name(table_name)} CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}"
end

# Maps logical Rails types to MySQL-specific data types.
def type_to_sql(type, limit = nil, precision = nil, scale = nil)
return super unless type.to_s == 'integer'

case limit
when 0..3
"smallint(#{limit})"
when 4..8
"int(#{limit})"
when 9..20
"bigint(#{limit})"
else
'int(11)'
end
end


# SHOW VARIABLES LIKE 'name'
def show_variable(name)
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4 comments on commit a375465

@matthuhiggins
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I would replace:
:integer => { :name => "int"}, :limit => 11 },

with:
:integer => { :name => "int"},

Otherwise, the default case of ‘int(11)’ is never executed.

@digitalhobbit
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Even with that change, this is causing problems when cloning the test database, as integer columns that were originally specified without an explicit limit in the migration now have a limit of 11, resulting in them being created as bigint(11) rather than int(11). This in turn breaks the clone when using foreign key constraints.

See [#55] for more details.

@tjoneseng
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This patch is not backwards compatible in general. The default for :integer was int(11), so the new range for “integer” should include 11 (see my meta-patch at http://timothynjones.wordpress.com/2008/06/10/change-to-activerecord-mysql-adapter-breaks-tests/).

@tarmo
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@tarmo tarmo commented on a375465 Jun 16, 2008

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timothynjones, this code is actually going to chance once more with: http://rails.lighthouseapp.com/projects/8994/tickets/420-interpret-limit-as-number-of-bytes

And the :limit is no longer going to specify the number of decimal places, instead if will specify the number of bytes, so I’d suggest not at all adding a :limit option to your integers unless you need bigint or mediumint or smallint. For schema.rb there should be no compatibility problems as I believe schema.rb has never dumped :limit for :integer types (rather the change would actually make schema.rb more accurate in being able to create correct integer types where it used to always create 4 byte integers).

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