Module: SchemaPlus::ForeignKeys::ActiveRecord::ConnectionAdapters::Mysql2Adapter

Defined in:
lib/schema_plus/foreign_keys/active_record/connection_adapters/mysql2_adapter.rb

Overview

SchemaPlus::ForeignKeys includes a MySQL implementation of the AbstractAdapter extensions.

Instance Method Summary collapse

Instance Method Details

#foreign_keys(table_name, name = nil) ⇒ Object 



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# File 'lib/schema_plus/foreign_keys/active_record/connection_adapters/mysql2_adapter.rb', line 32

def foreign_keys(table_name, name = nil)
  results = select_all("SHOW CREATE TABLE #{quote_table_name(table_name)}", name)

  table_name = table_name.to_s
  namespace_prefix = table_namespace_prefix(table_name)

  foreign_keys = []

  results.each do |result|
    create_table_sql = result["Create Table"]
    create_table_sql.lines.each do |line|
      if line =~ /^  CONSTRAINT [`"](.+?)[`"] FOREIGN KEY \([`"](.+?)[`"]\) REFERENCES [`"](.+?)[`"] \((.+?)\)( ON DELETE (.+?))?( ON UPDATE (.+?))?,?$/
        name = $1
        columns = $2
        to_table = $3
        to_table = namespace_prefix + to_table if table_namespace_prefix(to_table).blank?
        primary_keys = $4
        on_update = $8
        on_delete = $6
        on_update = ForeignKeyDefinition::ACTION_LOOKUP[on_update] || :restrict
        on_delete = ForeignKeyDefinition::ACTION_LOOKUP[on_delete] || :restrict

        options = { name: name,
                    on_delete: on_delete,
                    on_update: on_update,
                    column: columns.gsub('`', '').split(', '),
                    primary_key: primary_keys.gsub('`', '').split(', ')
        }

        foreign_keys << ::ActiveRecord::ConnectionAdapters::ForeignKeyDefinition.new(
          namespace_prefix + table_name,
          to_table,
          options)
      end
    end
  end

  foreign_keys
end

#remove_column(table_name, column_name, type = nil, **options) ⇒ Object

:enddoc:



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# File 'lib/schema_plus/foreign_keys/active_record/connection_adapters/mysql2_adapter.rb', line 12

def remove_column(table_name, column_name, type=nil, **options)
  foreign_keys(table_name).select { |foreign_key| Array.wrap(foreign_key.column).include?(column_name.to_s) }.each do |foreign_key|
    remove_foreign_key(table_name, name: foreign_key.name)
  end
  super table_name, column_name, type, **options
end

#remove_foreign_key(from_table, to_table = nil, **options) ⇒ Object 



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# File 'lib/schema_plus/foreign_keys/active_record/connection_adapters/mysql2_adapter.rb', line 19

def remove_foreign_key(from_table, to_table = nil, **options)
  if options[:if_exists]
    foreign_key_name = get_foreign_key_name(from_table, to_table, options)
    return if !foreign_key_name or not foreign_keys(from_table).detect{|fk| fk.name == foreign_key_name}
  end
  options.delete(:if_exists)
  super from_table, to_table, **options
end

#remove_foreign_key_sql(*args) ⇒ Object 



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# File 'lib/schema_plus/foreign_keys/active_record/connection_adapters/mysql2_adapter.rb', line 28

def remove_foreign_key_sql(*args)
  super&.sub(/DROP CONSTRAINT/, 'DROP FOREIGN KEY')
end

#reverse_foreign_keys(table_name, name = nil) ⇒ Object 



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# File 'lib/schema_plus/foreign_keys/active_record/connection_adapters/mysql2_adapter.rb', line 72

def reverse_foreign_keys(table_name, name = nil)
  results = select_all(<<-SQL, name)
SELECT constraint_name, table_name, column_name, referenced_table_name, referenced_column_name
  FROM information_schema.key_column_usage
 WHERE table_schema = #{table_schema_sql(table_name)}
   AND referenced_table_schema = table_schema
 ORDER BY constraint_name, ordinal_position;
  SQL

  constraints = results.to_a.group_by do |r|
    r.values_at('constraint_name', 'table_name', 'referenced_table_name')
  end

  from_table_constraints = constraints.select do |(_, _, to_table), _|
    table_name_without_namespace(table_name).casecmp(to_table) == 0
  end

  from_table_constraints.map do |(constraint_name, from_table, to_table), columns|
    from_table = table_namespace_prefix(from_table) + from_table
    to_table = table_namespace_prefix(to_table) + to_table

    options = {
      name: constraint_name,
      column: columns.map { |row| row['column_name'] },
      primary_key: columns.map { |row| row['referenced_column_name'] }
    }

    ::ActiveRecord::ConnectionAdapters::ForeignKeyDefinition.new(from_table, to_table, options)
  end
end