Module: DataMapper::Adapters::MysqlAdapter::Migration

Includes:
SQL
Included in:
DataMapper::Adapters::MysqlAdapter
Defined in:
lib/dm-core/adapters/mysql_adapter.rb

Overview

TODO: move to dm-more/dm-migrations

Defined Under Namespace

Modules: ClassMethods, SQL

Instance Method Summary collapse

Instance Method Details

#field_exists?(storage_name, field_name) ⇒ Boolean

TODO: move to dm-more/dm-migrations (if possible)

Returns:

  • (Boolean) 


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# File 'lib/dm-core/adapters/mysql_adapter.rb', line 52

def field_exists?(storage_name, field_name)
  statement = <<-EOS.compress_lines
    SELECT COUNT(*)
    FROM `information_schema`.`columns`
    WHERE `table_schema` = ?
    AND `table_name` = ?
    AND `column_name` = ?
  EOS

  query(statement, db_name, storage_name, field_name).first > 0
end

#storage_exists?(storage_name) ⇒ Boolean

TODO: move to dm-more/dm-migrations (if possible)

Returns:

  • (Boolean) 


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# File 'lib/dm-core/adapters/mysql_adapter.rb', line 39

def storage_exists?(storage_name)
  statement = <<-EOS.compress_lines
    SELECT COUNT(*)
    FROM `information_schema`.`tables`
    WHERE `table_type` = 'BASE TABLE'
    AND `table_schema` = ?
    AND `table_name` = ?
  EOS

  query(statement, db_name, storage_name).first > 0
end