📅  最后修改于: 2022-03-11 15:05:19.789000             🧑  作者: Mango
This type of command is usually used to copy the structure of one table
to another. In this case, EMPL_DEMO will have the same column structure
of employees , except for the keys or constraints. The 1=2 always
evaluates to False which prevents you from copying any of the rows.