Earlier quoted context omitted.
Also, SQL was designed back when most programming was done in assembler or C. Compared to assembler, SQL is easy. Programming itself has gotten a lot easier since.
SQL was designed by IBM in the 1970s, to run on mainframes. The community by whom and for whom it was developed was focused on PL/I and COBOL and largely didn't use C. The first implementation of SQL in C was probably Oracle V3 (released in 1983). IBM's equivalent SQL offerings around the same time (SQL/DS for VM/CMS and DB2 for MVS) were written in PL/I dialects and assembly, and COBOL, Fortran and PL/I were support…
https://asktom.oracle.com/pls/asktom/f?p=100:11:0::NO::P11_Q...
Oracle was originally written in fortran and then redone in C, which it has been written in ever since. In fact, when we ported Oracle to the mainframe for the first time we were faced with an issue -- do we rewrite Oracle in assembler (there was no c compiler on the mainframe back then) or do we write a C compiler? We wrote a C compiler.
On a side note, I remember watching an interview or reading an article (probably from Larry Ellison) who said IBM gave 1/3 of it's business to Intel, another 1/3 to Microsoft and the final 1/3 to Oracle. Pretty crazy.