Question

我有20个表Table100到Table119，所有表都有相同的结构，Name，StaffID，DeptID，Description

是否可以通过MySQL计算不同的名称，计算不同的StaffID，每个表的记录数？即20次？

输出类似于

Table100, 12, 15, 120
Table101, 10, 10, 130
etc..

可以添加其他表格，但它们都将以“Tablexxx”

开头

我可以使用PHP / Perl执行此操作，但我希望通过本机SQL运行它。

由于

Answer 1

您需要构建一个查询来执行此操作，例如：

select 'Table100' as which, count(distinct name) as NumNames, count(distinct StaffId) as NumStaff, count(*) as NumRecs from Table100 union all
select 'Table101' as which, count(distinct name) as NumNames, count(distinct StaffId) as NumStaff, count(*) as NumRecs from Table101 union all
select 'Table102' as which, count(distinct name) as NumNames, count(distinct StaffId) as NumStaff, count(*) as NumRecs from Table102 union all
. . .
select 'Table120' as which, count(distinct name) as NumNames, count(distinct StaffId) as NumStaff, count(*) as NumRecs from Table120;

在SQL中，无法“循环”一组表。你必须明确提到它们。您可以在应用程序中构造查询。或者，您可以使用Excel等工具构建查询。

尽管如此，许多具有相同格式的表都表明数据结构存在问题。通常，最好将这些数据存储在一个表中，而不是分散在许多表中。

MySQL - x表上的不同计数摘要

1 个答案: