Research On SQL Complier Of Database Engine

In the world produce a large amount of information every day, so to spread information worldwide with a varitety of ways. As an individual or business will be exposed to amounts of data information, the database is an essential tool which database management system referred to as DBMS is the core of the system, then to manage and manipulate these data. It can not only ensure the safety and integrity of the database, but also a comprehensive database to manipulate and manage. DBMS can provide the long-term storage, programming interfaces, transaction management. Database engine is essential for implement the function, it is used for storage, processing and protection of data in core services.In this thesis, a small database management system SQL language pre-compiler construction establish in the Windows environment. First begin from compiler theory, including knowledge, to the lexical analyzers and parser, and finally code generation and optimization, the compilation and processing of the SQL language in detail, In the system the SQL language is standard language, it is a high-level non-procedural programming language, users can use it in the high-level work, would not have developed the database storage methods, but also do not understand the specific storage way.This thesis described the various stages of the compilation process and related knowledge, including:regular expressions, finite automata, context-free grammars, LALR (1) grammar and so on. Then on the main stage and the compilation process to build the systems approach as the basis for a detailed description, including the use of LEX and YACC tool to generate lexical analyzers and parser, and gives them the SQL language compiler device to achieve a specific application process. SQL pre-compiler and then build on the methods and related technologies made a detailed route description.SQL pre-compiler of the whole idea is to initially build a generation tool LEX-lexical analyzer, and then by the YACC grammar parser generation tools to build out. These two parts as the front-end, then the virtual machine as an intermediate link, playing a connecting role, and finally back-end constructed by the B-Tree and buffer modules, together with the operating system to provide API interface, so that together constitute the implementation of the SQL pre-compiler.