17.3. Old versus New JOIN Syntax

One of the classics of software engineering is a short paper by the late Edsger Dijkstra entitled “Go To Statement Considered Harmful” (Dijkstra 1968, pp. 147-148). Dijkstra argued for dropping the GOTO statement from programming languages in favor of what we now call structured programming.

One of his observations was that programs that used blocks, WHILE loops, and IF-THEN-ELSE statements were easier to read and maintain. Programs that jumped around via GOTO statements were harder to follow, because the execution path could have arrived at a statement label from anywhere in the code.

With the SQL-92 Standard, we added a set of infixed join operators to SQL, making the syntax closer to the way that relational ...

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