According to Immerman, the complexity class associated with SQL queries is exactly the class of safe queries in $\mathsf{Q(FO(COUNT))}$ (first-order queries plus counting operator): SQL captures safe queries. (In other words, all SQL queries have a complexity in $\mathsf{Q(FO(COUNT))}$, and all problems in $\mathsf{Q(FO(COUNT))}$ can be expressed as an SQL query.)

Is there an extension of SQL (implemented and used in the industry) which captures $\mathsf{P}$,, i.e. that can express all polynomial-time computable queries and no others?

If there isn't, is there a reason? Are the queries that are needed in practice usually simple enough that there is no need for a stronger language?