Calcite test code

• This is the test code for Apache Calcite, include SQL parser，validator、optimizer anyone who are interested in calcite any use this code to know more about apache. by the away, welcome to communicate with me about calcite

• 这是有关于Apache Calcite测试代码， 包括SQL解析器、验证器及优化器，任何对calcite 有兴趣的同学都可以通过这份代码学习calicte. 同时也欢迎与我交流有关calcite的相关知识