Translation:If he had enough to drink, he would not be thirsty.
Learned from another course that the combination of "zou/zouden + hebben" is often replaced by "had/hadden" in order to simplify the sentence. Therefore "hij zou geen dorst hebben" can simplified to "hij had geen dorst". When in confusion, people go back to the full sentence to clarify.
In conditional sentences in English this is what is called a Conditional Type 2, where the if-clause is in the Simple Past and the main clause (the clause that is the result of the condition) has the structure "would + (bare infinitive)".
You can check it on the internet, for example, here https://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-2 and here http://www.learnenglish.de/grammar/conditional2.html
Yes, I agree with MentalPinball. Not only is it ungrammatical, we'd never say it in English. Because it's a conditional sentence, it's not clear what that means. Does it mean "he wouldn't be thirsty now" or "he wasn't thirsty then".
Apart from that, it's not completely incorrect to talk about "having thirst", but it's extremely unusual, and a native speaker would almost certainly always talk about "being thirsty".
So it's wrong, on several levels.
I think the English sentence is missing a "had" for this. It should be "If he had had enough to drink..."
Otherwise its grammatically incorrect. One had needs another verb, ie "If he had drunk enough". The first puts us in past, the second is the verb. Probably not noticed much because most would contract the first - "if he'd had enough to drink".
I'm thinking this is because the simple English past "he drank" would be translated into Dutch as "hij dronk" (using the Dutch imperfect/simple past) or "hij heeft gedronken" (using the Dutch present perfect construction). (Note that "drinken" is a strong Dutch verb - http://www.dutchgrammar.com/en/?n=Verbs.Ir03. See the following links for more about which construction to use to describe events in the past - http://www.dutchgrammar.com/en/?n=Verbs.Re11 and http://www.dutchgrammar.com/en/?n=Verbs.Re14.)
Looking carefully at the construction of the clause "als hij genoeg te drinken had", "had" is the Dutch simple past of "to have" and "drinken" is the infinitive. The construction used here is really "hebben te drinken" ("to have to drink"). Because clauses starting with "als" put the main verb at the end of the clause, we end up with "te drinken had", which understandably can mislead learners into thinking this is equivalent to the English past tense "drank".
The problem here is that what you are proposing here is what in English is called a mixed conditional (check here: http://www.englishpage.com/conditional/mixedconditional.html , it's the third set of examples), and the correct version (the correct translation) is a Conditional type 2 (which refers to an unlikely situation in the present) (for which I provided the link in a comment above, check it out).
My guess is that if it had been a mixed conditional, then the Dutch version would have been entirely different. (and this last sentence I just wrote is a Conditional type 3, which refers to a hypothetical situation in the past, so the condition conveyed in the if-clause cannot be fulfilled). But this Dutch version I cannot provide given the fact that I'm not a native Dutch speaker.
there are many ways to say the same thing.. "Zouden" is the past of "Zullen" so when you use it in a phrase it means the past of the other verb that follows it (verb in infinitive in the case of present conditional) but so you could also replace it for the direct imperfectum verb of the infinite verbum that goes with it.
Als ik een auto zou hebben, zou ik ermee naar mijn werk gaan
Als ik een auto zou hebben, ging ik ermee naar mijn werk
Als ik een auto had, zou ik ermee naar mijn werk gaan
Als ik een auto had, ging ik ermee naar mijn werk
all of those phrases mean the same: If i would have a car, I would go with it to my work.
so even though you can replace: ZOU HEBBEN = HAD (past of hebben for singular subjects) and ZOU GAAN= GING (past of gaan for singular subjects) everything has the same meaning