SQL logic query analysis (Supplement)

In my previous blog on SQL logic query parsing, this article describes in detail the steps of SQL logic Query Processing and some important knowledge about the SQL language. For the integrity of SQL logic query processing, we will learn more about SQL logic Query Processing in this article as a supplement to the previous blog. Including table operators (JOIN, APPLY

In my previous blog on SQL logic query parsing, this article describes in detail the steps of SQL logic Query Processing and some important knowledge about the SQL language. For the integrity of SQL logic query processing, we will learn more about SQL logic Query Processing in this article as a supplement to the previous blog. Including table operators (JOIN, APPLY

Contents

In my previous blog "SQL logic query Parsing", we described in detail the steps of SQL logic Query Processing and some important knowledge about SQL language. For the integrity of SQL logic query processing, we will learn more about SQL logic Query Processing in Hong Kong Space in this article to supplement the previous blog. Includes the JOIN, APPLY, ignore, and unregister operators, OVER clauses, and set operators (UNION, record-free space, limit T, and INTERSECT ).

Table Operators

From SQL server 2008, SQL queries support four table operators: JOIN, APPLY, ignore, and unregister. Here, APPLY, exclude and unregister are not ANSI standard operators, Hong Kong virtual hosts, but special extensions in T-SQL.

The format of the four table operators is listed below:

(J) {} On_predicate> () {} APPLY (P) Aggregate (spreading_element> IN ( ) (U) Unregister (target_names_col> IN ( )