quick help

[Monkuar]

what does

 

WHERE p.pid IN(0,4561,0)

 

mean? I know it's lokoing for DATA FROM p.pid = 4561, but WHAT THE HELL DOES THE 0,  ,0 mean?

 

Thanks

[RussellReal]

IN is sort of an "IS IN"

 

Understanding the WHERE clause.. WHERE is basically IF statements that are compared against the rows in the table..

 

WHERE 1 = 1

 

is a valid where clause, because when you do

 

WHERE id = 17

 

its basically evaluating the >>id<< and then comparing the two values which would look something like:

 

WHERE 47 = 17

 

now, the IN clause, basically is looking for VALUE in VALUESET

 

for example

 

WHERE id IN (1,2,3)

 

that code would be evaluated and look like this:

 

WHERE 177 IN (1,2,3)

 

and would be false, therefore the row will not be taken

 

why would it be false?

 

because 177 is not equal to 1 OR 2 OR 3

 

so what your IN clause is looking for..

 

WHERE 177 = 0 OR 177 = 4561 OR 177 = 0

 

which makes no sense, which is why I gave you a more in depth explanation

[Monkuar]

IN is sort of an "IS IN"

 

Understanding the WHERE clause.. WHERE is basically IF statements that are compared against the rows in the table..

 

WHERE 1 = 1

 

is a valid where clause, because when you do

 

WHERE id = 17

 

its basically evaluating the >>id<< and then comparing the two values which would look something like:

 

beautiful

 

topic solved

 

WHERE 47 = 17

 

now, the IN clause, basically is looking for VALUE in VALUESET

 

for example

 

WHERE id IN (1,2,3)

 

that code would be evaluated and look like this:

 

WHERE 177 IN (1,2,3)

 

and would be false, therefore the row will not be taken

 

why would it be false?

 

because 177 is not equal to 1 OR 2 OR 3

 

so what your IN clause is looking for..

 

WHERE 177 = 0 OR 177 = 4561 OR 177 = 0

 

which makes no sense, which is why I gave you a more in depth explanation