Seriously, if you want a legal copy that costs something like 200 Swiss francs. This isn't how serious comp-sci standards work (the TCP people just throw out RFCs). Especially since the SQL standards committee probably don't know how to design a language given what most SQL implementations look like. I can't be sure though, I'll probably never be in a position to read the official standard.
Reflect on the madness. Postgres? Free. SQL Standard? 200 francs. Postgres makes a better standard than the SQL standard. The ISO standard thing isn't here to support people using or building SQL databases.