为什么没有数据库完全支持ANSI或ISO SQL标准?

If I were designing a oil refinery, I wouldn't expect that materials from different vendors would not comply with published standards in subtle yet important ways. Pipework, valves and other components from one supplier would come with flanges and wall thicknesses to ANSI standards, as would the same parts from any other supplier. Interoperability and system safety is therefore assured.If I were designing a oil refinery, I wouldn't