初学者可以在哪里运行他们的SQL代码？如果它是PL，那么为什么它没有编译器？

I am totally new to the subject of databases and I have only theoretical knowledge about it.I want to run the SQL commands I read about but totally clueless where to run it.The definition says SQL is a special purpose programming language.If so why doesn't it have a compiler?And if I have to install in a RDBMS on my computer to practice SQL, what is the one you would suggest for learners?Can SQL commands be run in all RDBMS? I am totally despondent about it,utterly clueless.Please help me take the first step.Just a simple thing--Where on earth to run those SQL commands?I am totally new to the subject of databases an