A brief discussion on the factorial of Oracle subquery (with use)

Recently learning Oracle, want to improve the efficiency and legibility of the written statement, today's note is about the subquery factor words such a thing

A factorial query may not necessarily improve efficiency, but it can improve the readability of the program significantly

        The result of the--with statement with the Sales_c (select Sales,e_no,e_name from Emplyee) SELECT * from sales_c;--query is (select Sales,e_no,e_na Me from Emplyee) The contents of this list are--with once, and can be used arbitrarily in the following example, which improves the readability of the code-for example with the Sales_c (        select Sales,e_no,e_name from Emplyee),    name_c (       select Sales,e_name from Sales_c) SELECT * from sales_c,name_c;--it's really handy to read.

Principle: Oracle will solidify this query_name with Query_name as a temporary table or view to improve query efficiency

A brief discussion on the factorial of Oracle subquery (with use)