diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb')
| -rw-r--r-- | activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb | 52 |
1 files changed, 48 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb index d3499cea72..0216a8f4ac 100644 --- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb @@ -24,10 +24,53 @@ module ActiveRecord # Returns an array of indexes for the given table. # def indexes(table_name, name = nil) end + # Checks to see if an index exists on a table for a given index definition + # + # === Examples + # # Check an index exists + # index_exists?(:suppliers, :company_id) + # + # # Check an index on multiple columns exists + # index_exists?(:suppliers, [:company_id, :company_type]) + # + # # Check a unique index exists + # index_exists?(:suppliers, :company_id, :unique => true) + # + # # Check an index with a custom name exists + # index_exists?(:suppliers, :company_id, :name => "idx_company_id" + def index_exists?(table_name, column_name, options = {}) + column_names = Array.wrap(column_name) + index_name = options.key?(:name) ? options[:name].to_s : index_name(table_name, :column => column_names) + if options[:unique] + indexes(table_name).any?{ |i| i.unique && i.name == index_name } + else + indexes(table_name).any?{ |i| i.name == index_name } + end + end + # Returns an array of Column objects for the table specified by +table_name+. # See the concrete implementation for details on the expected parameter values. def columns(table_name, name = nil) end + # Checks to see if a column exists in a given table. + # + # === Examples + # # Check a column exists + # column_exists?(:suppliers, :name) + # + # # Check a column exists of a particular type + # column_exists?(:suppliers, :name, :string) + # + # # Check a column exists with a specific definition + # column_exists?(:suppliers, :name, :string, :limit => 100) + def column_exists?(table_name, column_name, type = nil, options = {}) + columns(table_name).any?{ |c| c.name == column_name.to_s && + (!type || c.type == type) && + (!options[:limit] || c.limit == options[:limit]) && + (!options[:precision] || c.precision == options[:precision]) && + (!options[:scale] || c.scale == options[:scale]) } + end + # Creates a new table with the name +table_name+. +table_name+ may either # be a String or a Symbol. # @@ -205,6 +248,7 @@ module ActiveRecord # remove_column(:suppliers, :qualification) # remove_columns(:suppliers, :qualification, :experience) def remove_column(table_name, *column_names) + raise ArgumentError.new("You must specify at least one column name. Example: remove_column(:people, :first_name)") if column_names.empty? column_names.flatten.each do |column_name| execute "ALTER TABLE #{quote_table_name(table_name)} DROP #{quote_column_name(column_name)}" end @@ -292,7 +336,7 @@ module ActiveRecord @logger.warn("Index name '#{index_name}' on table '#{table_name}' is too long; the limit is #{index_name_length} characters. Skipping.") return end - if index_exists?(table_name, index_name, false) + if index_name_exists?(table_name, index_name, false) @logger.warn("Index name '#{index_name}' on table '#{table_name}' already exists. Skipping.") return end @@ -313,7 +357,7 @@ module ActiveRecord # remove_index :accounts, :name => :by_branch_party def remove_index(table_name, options = {}) index_name = index_name(table_name, options) - unless index_exists?(table_name, index_name, true) + unless index_name_exists?(table_name, index_name, true) @logger.warn("Index name '#{index_name}' on table '#{table_name}' does not exist. Skipping.") return end @@ -350,11 +394,11 @@ module ActiveRecord end end - # Verify the existence of an index. + # Verify the existence of an index with a given name. # # The default argument is returned if the underlying implementation does not define the indexes method, # as there's no way to determine the correct answer in that case. - def index_exists?(table_name, index_name, default) + def index_name_exists?(table_name, index_name, default) return default unless respond_to?(:indexes) indexes(table_name).detect { |i| i.name == index_name } end |