I am having a hard time accurately describing my skillset on a resume. I am comfortable putting the statement "Proficient in Java Development" on my resume, as I have been coding in Java for 5+ years and am very familiar with it. However, I am less comfortable saying that I am proficient in SQL. I've used SQL but don't know many of the intricacies of specific SQL implementations or know much beyond basic statements (Insert, Delete, Select, Joins, Conditions, etc.).
How do I describe my abilities in SQL and other areas like it?
Somewhat related: What heading should be written in a resume instead of "Technical Expertise" when I am not an "expert"? The accepted answer to the question recommends 'Experience', but that doesn't seem clear enough.
Edit - I want to list the skills in question in terms of proficiency level, not in another format. With Java it is easy to estimate the years of experience because I use it frequently, but I use SQL and other skills sporadically.