module DatabaseHelper # Check if database adapter equals to the specified name def db_adapter_is?(adapter_name) ActiveRecord::Base.connection.adapter_name == adapter_name end # Create gist trigram index. PostgreSQL only! def add_gist_index(table, column) ActiveRecord::Base.connection.execute( "CREATE INDEX index_#{table}_on_#{column} ON " \ "#{table} USING gist (#{column} gist_trgm_ops);" ) end # Create gin trigram index with filtered out html tags. PostgreSQL only! def add_gin_index_without_tags(table, column) ActiveRecord::Base.connection.execute( "CREATE INDEX index_#{table}_on_#{column} ON " \ "#{table} USING gin ((trim_html_tags(#{column})) gin_trgm_ops);" ) end # Get size of whole table & its indexes # (in bytes). PostgreSQL only! def get_table_size(table) ActiveRecord::Base.connection.execute( "SELECT pg_total_relation_size('#{table}');" ).getvalue(0, 0).to_i end # Get octet length (in bytes) of given column # of specified SINGLE ActiveRecord. PostgreSQL only! def get_octet_length_record(object, column) get_octet_length( object.class.to_s.tableize, column, object.id ) end # Get octet length (in bytes) of given column # in table for specific id. PostgreSQL only! def get_octet_length(table, column, id) ActiveRecord::Base.connection.execute( "SELECT octet_length(cast(t.#{column} as text)) FROM #{table} " \ "AS t WHERE t.id = #{id};" ).getvalue(0, 0).to_i end # Adds a check constraint to the table def add_check_constraint(table, constraint_name, constraint) ActiveRecord::Base.connection.execute( "ALTER TABLE " \ "#{table} " \ "DROP CONSTRAINT IF EXISTS #{constraint_name}, " \ "ADD CONSTRAINT " \ "#{constraint_name} " \ "CHECK ( #{constraint} ) " \ "not valid;" ) end # Remove constraint from the table def drop_constraint(table, constraint_name) ActiveRecord::Base.connection.execute( "ALTER TABLE " \ "#{table} " \ "DROP CONSTRAINT IF EXISTS #{constraint_name}; " ) end end