Why do you think SQL doesn't qualify? it's certainly not the only example of declarative programming, and maybe not the most interesting, but it is one which most developers have come across.
Let's also remember that many companies stuck with big RDBMs systems have entire teams of people whose job includes turning declarative statements into extremely procedural ones.
So in practice, writing a SQL statement has little to do with making a query readable, but with abusing knowledge of internals to make it work fast. So declarative, not so much.
Has anyone made an RDBM that let you write SQL and separately control how it is evaluated?
For example, I consider the sublanguage in printf to be more declarative than the rest of C as well.
SQL as it stands, especially in contrast to what the existing models were at the time it was introduced, such as CODASYL.
SQL is the one language we use that somewhat operates at the level of thought.