PostgreSQL has a useful function called GREATEST. It returns the largest value of those passed to it as documented here.
Is there any equivalent in SQLite?
As a note, I only need it to work with 2 arguments.
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2 Answers
SELECT MAX(1,2,..)
ref: https://sqlite.org/lang_corefunc.html#maxoreunc
max(X,Y,...)The multi-argument max() function returns the argument with the maximum value, or return NULL if any argument is NULL. The multi-argument max() function searches its arguments from left to right for an argument that defines a collating function and uses that collating function for all string comparisons. If none of the arguments to max() define a collating function, then the BINARY collating function is used. Note that max() is a simple function when it has 2 or more arguments but operates as an aggregate function if given only a single argument.
4 Comments
zlatko
Ok, can someone explain strange behavior of max function with strings. select max ('rb','VISA', 'Visa', 'Visa Card1', 'VISA VISA Card', 'Visaaa') returns 'rb', Why?!?
apenwarr
@zlatko: sounds like a case-sensitive comparison. lowercase is coming after uppercase.
Vérace
@zlatko - check out an ASCII chart!
pdw
Be careful, the behavior with NULL is different: PostgreSQL
GREATEST returns NULL only if all arguments are NULL. SQLite MAX returns NULL if any argument is NULL.using a second value in MAX(value1, value2) would be the equivalent
Example:
UPDATE products SET Quantity = MAX(Quantity - @value, 0)...
if (Quantity - value) return a "Negative Number -0" then Max( , 0) will return 0
because 0 is bigger than -0 / -1 / -2 ... and so on
Max( , 1) will return 1 if the same condition (Quantity - value) return 0 or a Negative Number .. etc, you get the idea !
if we assume that both
Quantityand@valuecould be NULL then use the combination:IFNULL(MAX(Quantity-@value,0),0)
IFNULL(..., 0)will return the second value of your choice IF the first one is NULL
