mysql - 多个 SQL 计入单个结果集

Question

大家好

我正在尝试做一些我认为在 MYSQL 上不可能的事情。

我们有一个非常大的数据库，我们可以从中提取我们创建的产品的生产报告。目前，我们运行多个查询来获取这些结果，然后将数据手动传输到表中，然后将其发送给需要报告的任何人。

有没有更简单的方法来做到这一点。 IE 单个查询。

我运行的查询示例

a. SELECT count(id) from ProductA_T where created between '<date>' and '<date>' and productstatus = "<successful>";
b. SELECT count(id) from ProductB_T where created between '<date>' and '<date>' and productstatus = "<successful>";
c. SELECT count(id) from ProductC_T where created between '<date>' and '<date>' and productstatus = "<successful>";

我正在寻找的结果示例

1. 产品A 产品B 产品C
2. 500 500 500

Answer 1

您可以将所有内容放入 Select 子句中，如下所示:

Select
(SELECT count(id) from ProductA_T where created between '<date>' and '<date>' and productstatus = "<successful>") as CountA
(SELECT count(id) from ProductB_T where created between '<date>' and '<date>' and productstatus = "<successful>") as CountB
(SELECT count(id) from ProductC_T where created between '<date>' and '<date>' and productstatus = "<successful>") as CountC

这样你就会有这样的输入:

• 计数 A 计数 B 计数 C
• 500 500 500

您稍后可以轻松添加更多计数