SQL analysis method and SQL analyzer

Abstract

The embodiment of the invention provides an SQL analysis method and an SQL analyzer, and the method comprises the steps: generating a character data flow with an SQL type label according to a to-be-analyzed source structured query language SQL statement and a corresponding SQL type; analyzing the character data stream into a corresponding grammar mark stream according to a lexical rule and a grammar rule which are matched with the character data stream and are found based on the SQL type tag; generating a corresponding abstract syntax tree according to the syntax expression of each syntax phrase in the syntax mark flow; and converting the abstract syntax tree into an output data stream with an output type configured corresponding to the source SQL statement, and outputting the output datastream. By applying the scheme provided by the embodiment of the invention, the analysis of SQL statements of various SQL types can be supported, the application range is expanded, and the flexibilityand the expandability are improved.

Description

technical field [0001] The embodiment of the present invention relates to the technical field of databases, in particular to an SQL parsing method and an SQL parser. Background technique [0002] With the rapid development of information technology, the application of database is becoming more and more common. SQL (Structured Query Language, Structured Query Language) is a set of operation commands specially established for databases, and is a fully functional database language. When using it, you only need to issue the "what to do" command, and the "how to do it" does not need to be considered by the user. SQL is powerful, easy to learn, and easy to use. It has become the basis of database operations, and now almost all databases support SQL. [0003] Currently, most of the work performed on a database is done with SQL statements. In order to execute the SQL statement, it is necessary to analyze the SQL statement, generate a logical execution plan, and generate a physica...

AI Technical Summary

Problems solved by technology

[0004] Existing SQL parsers are generally highly coupled in large-scale projects, and a single type of database general specification is usually configured in large-scale projects. Therefore, existing SQL parsers usually only support SQL parsing for a single type of database. That is, the parsing function is aimed at a specific type of SQL statement

Moreover, the existing SQL parsers usually embed the lexical rule base, grammar rule base, abstract syntax tree parsing relationship, etc. required in the parsing of SQL statements into the program code, with fixed functions and cannot be modified at the application level

In this way, when faced with the analysis requirements of different types of SQL statements, the existing SQL parser cannot meet the above requirements, and has poor flexibility and narrow application range.

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