METHOD AND SYSTEM FOR GENERATING OPTIMAL MEMBERSHIP-CHECK QUERIES

摘要

A method and system of transforming a query at a web server are provided. An abstract syntax tree representing the query can be traversed from the top down, for each node in the abstract syntax tree: labeling the node as being in a conjunct position when the node's parent is a WHERE node; labeling the node as being not in a conjunct position when the node's parent is an OR node; and labeling the node identically to the node's parent node when the node's parent is an AND node. Then any IN node in the abstract syntax tree can be transformed to an INNER JOIN node when the IN node is labeled as being in a conjunct position. The abstract syntax tree can be converted into a Structured Query Language (SQL) query, which can then be passed to a database for processing.

主权项

1. A method of transforming a query at a web server, the method comprising:
traversing an abstract syntax tree representing the query, for each node in the abstract syntax tree:
labeling the node as being in a conjunct position when the node's parent is a WHERE node;labeling the node as being not in a conjunct position when the node's parent is an OR node;labeling the node identically to the node's parent node when the node's parent is an AND node; transforming any IN node in the abstract syntax tree to an INNER JOIN node when the IN node is labeled as being in a conjunct position; converting the abstract syntax tree into a Structured Query Language (SQL) query; and transmitting the SQL query to a database for processing.