‘Union查询就是先去重，再排序(即先把重复的项进行了去重，再把ID字段进行排序)

‘Union all查询就是把两张表连接在一起

Sub union联合查询()
SQL = "Select * from 表1 union Select * from 表2"
End Sub

Sub union联合查询()
SQL = "Select * from 表1 union all Select * from 表2"
End Sub

‘来源B站：孙兴华 VBA 查询篇

union联合查询和union all联合查询的主要区别