Priority of AND and OR operator in Mysql select qu

问题:

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Closed 7 years ago.

I have a written a mysql select query to fetch schedule details based on origin states,origin city,destination state and destination city. In my query i have used AND and OR operator.

Here is my query,

SELECT * FROM TruckLoadSchedule ts 
WHERE ts.originState IN (states) AND ts.originCity IN (cities) 
   OR ts.destState IN (states) AND ts.destCity IN (cities);

But I need to know the priority of AND and OR operator in the above query, i mean to say will it do something like this (X AND Y) OR (M AND Q) internally?

回答1:

Yes, AND has higher precedence than OR. x and y are bound together, m and q are bound together, then the resulting expressions are ORed.

回答2:

AND has a higher priority than OR in every programming language I have ever seen, and I've seen several dozen at close quarters, and implemented a few myself. This question was basically settled in 1960 with the Algol-60 report, if not already in Fortran (1957).

[There was one exception but it was a mis-implemented language with no operator precedence at all. I fixed that.]

回答3:

Yes it will do something like (X AND Y) OR (M AND Q). AND operator's priority is higher than OR.

For more see MySQL: Operator Precedence