A Better Query Language than SQL
Leland Richardson, Founder of Tech.Pro has recently published a very interesting article about BQL, his visions of a better query language (than SQL). The deciding feat of his new language proposal is the fact that it is really a superset of SQL itself.
SQL is a very rich and expressive language to query relational databases. But it is awkward in many aspects, and a lot of people perceive it to be evolving only slowly – even if that is not true, considering the pace of SQL standards. But the standard is one thing, the implementations another – especially in the enterprise. When we blog about SQL, we’re constantly surprised ourselves, how awesome the PostgreSQL dialect is. But often, PostgreSQL actually just implements the standard. So there is hope that we’re getting somewhere.
Nonetheless, in Leland’s article, there are a couple of ideas worth picking up. From our point of view, these are mainly:
Flexibility in ordering the SELECT
clause and the table expression
In SQL, SELECT
is always the first keyword. It must be expressed before the table expression. We’ve shown in a previous article that this is quite confusing for many SQL users. While the existing syntax should continue to exist, it would be good to be able to inverse the SELECT
clause and the table expression.
FROM table WHERE predicate GROUP BY columns SELECT columns
Remember, the table expression contains FROM
, WHERE
, GROUP BY
clauses, as well as vendor-specific CONNECT BY
clauses and others:
<query specification> ::= SELECT [ <set quantifier> ] <select list> <table expression>
This language feature is already available in LINQ, by the way.
Implicit KEY JOINs
This feature is also available in jOOQ, using the ON KEY
clause. Note that Sybase also supports ON KEY
joins:
from post key join user key join comment select *
Named projections
This is one of the features we really wish that the SQL language had. However, we wouldn’t count on specifying projections in a dedicated syntax. We had rather use an extension to the table expression syntax, allowing for a table to produce “side-tables” as such:
from dbo.users with projection as ( firstName, lastName, phoneNumber, email ) select projection.*
In the above example, projection
is really nothing else than another table expression that is derived from the users
table. From a SQL syntax semantics, this would be extremely powerful, because such projections would inherit all syntactic features of a regular table. We’ve blogged about this before, when we called that feature “common column expressions”.
Conclusion
Leland has lots of other ideas. He’s just at the beginning of a project that will still need a lot of refinement. The feedback he got on reddit, however, is rather good. Clearly, there is a lot of potential in creating “BQL” for SQL what
Let’s see where this endeavour leads. We’ll certainly be keeping an eye out for BQL’s next steps.
Reference: | A Better Query Language than SQL from our JCG partner Lukas Eder at the JAVA, SQL, AND JOOQ blog. |