SQL查询是否受使用的DBMS限制？ [英] Are SQL queries limited by the DBMS used?

问题描述

我最近读过一些文章，试图初步了解SQL和MySQL之间的区别，并且我从另一篇帖子中得到了有用的报价。

I've seen reading recently to try and understand initially what the difference was between SQL and MySQL, and I encountered a useful quote from another post "Basically, MySQL is one of many books holding everything, and SQL is how you go about reading that book.".

取决于所使用的后端，即MySQL与PostgreSQL。 SQL查询是否突然变得无效？

特别是关系DBMS与非关系DBMS ？

推荐答案

每个数据库都实现自己的SQL语言方言。这些方言可以以简单方式和基本方式变化。例如：

Each database implements its own dialect of the SQL language. The dialects can vary in simple ways and in fundamental ways. For instance:

• 函数可能具有不同的名称（例如 len（） vs length（））。


• 数据库可能未实现某些功能（例如 row_number（））。


• 数据库可能不支持公用表表达式。


• 数据库可能不支持某些功能，例如完全外部联接。

• Functions might have different names (say len() vs length()).
• Databases might implement not implement some set of functions (such as row_number()).
• Databases might not support common table expressions.
• Databases might not support certain functionality, such as full outer join.

列表确实还在继续。您应该将SQL视为一堆方言。它们彼此之间有很大的重叠，但是彼此之间却有差异-就像世界各地说英语的方言一样。

The list really goes on. You should think of SQL as a bunch of dialects. They significantly overlap each other, but each has differences -- something like the dialects of English spoken around the world.

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