MySQL如何使用日期范围填充表格？

MySQL如何使用日期范围填充表格？

在MySQL中，填充数据是一个常见的任务。有时，我们需要向表中插入一些日期范围内的数据。这时，我们可以使用日期范围填充表格的方法。

假设我们有一个名为“sales”的表格，其中包含以下列：date、product、quantity和price。我们想要向其中添加当前日期到未来30天的数据，以每天一个产品的方式。我们可以使用以下步骤来填充表格：

1. 创建一个日期范围

我们可以使用MySQL提供的DATE_ADD()和CURDATE()函数来创建一个日期范围。例如，下面的表达式将返回未来30天的所有日期：

SELECT DATE_ADD(CURDATE(), INTERVAL 1 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 2 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 3 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 4 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 5 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 6 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 7 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 8 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 9 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 10 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 11 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 12 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 13 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 14 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 15 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 16 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 17 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 18 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 19 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 20 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 21 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 22 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 23 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 24 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 25 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 26 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 27 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 28 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 29 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 30 DAY) AS date;

这将返回一个包含未来30天日期的表格。

2. 插入数据

我们可以使用INSERT INTO语句向sales表格中插入数据。例如，下面的语句将在“date”列中插入上述所创建的日期范围内的所有日期，并在“product”列中插入“apple”：

INSERT INTO sales (date, product)
SELECT date, 'apple'
FROM (
SELECT DATE_ADD(CURDATE(), INTERVAL 1 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 2 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 3 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 4 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 5 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 6 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 7 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 8 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 9 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 10 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 11 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 12 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 13 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 14 DAY) ASdate UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 15 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 16 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 17 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 18 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 19 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 20 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 21 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 22 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 23 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 24 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 25 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 26 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 27 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 28 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 29 DAY) AS date UNION
SELECT DATE_ADD(CURDATE(), INTERVAL 30 DAY) AS date
) AS dates;

3. 填充其他列

我们可以使用UPDATE语句来填充表格的其他列。例如，下面的语句将在“quantity”列中插入1，并在“price”列中插入10.99：

UPDATE sales
SET quantity = 1, price = 10.99;

现在，sales表格中应该包含了当前日期到未来30天的每一天对应一个‘apple’产品、1个数量和10.99的价钱。

阅读更多：MySQL 教程

总结

本文介绍了如何使用MySQL的函数和语句来填充表格的日期范围。通过这种方法，我们可以轻松地向表格中插入大量数据，提高工作效率。