Why does no database fully support ANSI or ISO SQL standards?

Question

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, v

Answer 1

In the software industry you have some standards that are really standards, i.e., products that don't comply with them just don't work. File specifications fall into that category. But then you also have "standards" that are more like guidelines: they may defined as standards with point-by-point definitions, but routinely implemented only partially or with significant differences. Web development is full of such "standards", like HTML, CSS and "ECMAScript" where different vendors (i.e. web browsers) implement the standards differently.

The variation causes headaches, but the standardization still provides benefits. Imagine if there were no HTML standard at all and each browser used its own markup language. Likewise, imagine if there were no SQL standard and each database vendor used its own completely proprietary querying language. There would be much more vendor lock-in, and developers would have a much harder time working with more than one product.

So, no, ANSI SQL doesn't serve the same purpose as ANSI standards do in other industries. But it does serve a useful purpose nonetheless.