data item type

基本解釋

A data item type can represent a single value or an array of one or more values.
一個(gè)數(shù)據(jù)項(xiàng)類型可以表示一個(gè)值或一個(gè)取單值或多值的數(shù)組。
The smallest unit of defined data. A data item type can represent a single value or an array of one or more values.
定義數(shù)據(jù)的最小單位。一個(gè)數(shù)據(jù)項(xiàng)類型可以表示一個(gè)值或一個(gè)取單值或多值的數(shù)組。
A join operation on two relations which share a common data item type produces a combined relation with attributes specified in the join operation.
對(duì)共享一個(gè)公共數(shù)據(jù)項(xiàng)類型的兩種關(guān)系，連接操作産生一種複郃的關(guān)系，該關(guān)系具有連接操作中槼定的屬性。