本书特色：主要介绍 SQL 的语法规则及在实际开发中的应用，并且对 SQL 在 MySQL、

MS SQL Server、Oracle 和 DB2 中的差异进行了分析；详细讲解数据库对增、删、改、查等

SQL的支持并给出了相应的SQL 应用案例；透彻分析函数、子查询、表连接、不同DBMS中

的 SQL 语法差异、SQL 调优、NULL 值处理、事务、开窗函数等高级技术；通过对实际案例

开发过程的详细分析，使读者掌握 SQL的综合应用技巧。 -The book features: introduces SQL syntax rules and the actual development of the application, and SQL in MySQL, MS SQL Server, Oracle and DB2 in an analysis of the differences　details on the database by adding, changing, check, etc. SQL support and the corresponding SQL Application　a thorough analysis of functions, subqueries, table connected to a different DBMS difference in SQL syntax, SQL tuning, NULL value handling, services, advanced technology, such as window function　by the actual case of a detailed analysis of the development process so that readers grasp the comprehensive application of skills in SQL.