[einhverfr]

I disagree with those criticisms of SQL, but I think it is inherently flawed from another perspective. Obviously how textbooks portray SQL has nothing to do with whether it is inherently flawed.

The real issues with SQL come down to the fact that it is an imperfect representation of relational math, and then also the dreaded ambiguity regarding NULLs.

The problem with NULLs is that NULL is used to refer to two very distinct conditions. In one case (outer joins) they are used to refer to a NULL set. In another, unknown values. These really should be distinct values.