Postage SQL 是一個(gè)用于處理郵政數(shù)據(jù)的 SQL 數(shù)據(jù)庫(kù)。以下是一個(gè)簡(jiǎn)單的示例,展示了如何編寫 Postage SQL 查詢。假設(shè)我們有一個(gè)名為 postal_data
的表,其中包含以下列:id
, sender_id
, receiver_id
, weight
, size
, country
, postage_cost
。
SELECT * FROM postal_data;
SELECT * FROM postal_data WHERE sender_id = 'sender123';
SELECT * FROM postal_data WHERE receiver_id = 'receiver456';
SELECT * FROM postal_data WHERE weight > 100;
SELECT * FROM postal_data WHERE size = 'A4';
SELECT * FROM postal_data WHERE country = 'China' AND sender_id IN (SELECT id FROM postal_data WHERE country = 'China') AND receiver_id IN (SELECT id FROM postal_data WHERE country = 'China');
SELECT * FROM postal_data WHERE postage_cost > 5;
這些示例展示了如何使用基本的 SQL 查詢操作符(如 SELECT
, FROM
, WHERE
, AND
, OR
)編寫 Postage SQL 查詢。根據(jù)實(shí)際需求,您可能需要編寫更復(fù)雜的查詢。