SQL选择合并多个表结果

Question

我想在多个表上运行select查询并合并结果。例如，我想将Last_month服务器可用性报告与current_month可用性报告合并。我有两个表Last_table1和current_table1

Last_table1
===========
Hosts    Availability
Server1      99.99%
Server2      87.55%


Current_table1
==============
Hosts    Availability
Server1     78.00%
Server2     100.00%

我想合并两个表，需要结果如下。我如何编写选择查询？

Hosts         Last       current
Server1      99.99%      78.00%
Server2      87.55%      100.00%

Answer 1

您需要执行JOIN，并在适当的位置显示正确的列：

SELECT 
  L.Hosts, L.Availability AS Last, C.Availability AS Current
FROM 
  Last_Table1 L
INNER JOIN 
  Current_Table1 C
ON 
  C.Hosts = L.Hosts