In what sequence do the operators work?

[Jaswanth Singh]

Dear Contributors,

I am new to VBA and SQL and I rquest your help.

Please explain me how the operators work?
In what sequence?
How to put perantheses for the opearation sequence being "OR" first and "AND" next?

here is the code:

einSqlStmt = einSqlStmt1 & _
" IN ( " & vorfilterString & ", NOT " & vorfilterString1 & " AND NOT " & vorfilterString2 & " ) "




Thanks in advance for any help.

Regards,
Jaswanth

[pod]

that is a loaded question ...

but here goes a few basic rules:


AND: all [statement]s must be true
Ex1: TRUE = [TRUE] AND [TRUE]
Ex2: FALSE= [TRUE] AND [FALSE]

OR: at least one [statement] must be true
Ex3: TRUE = [TRUE] OR [TRUE] OR [TRUE]
Ex4: TRUE = [FALSE] OR [TRUE] OR [FALSE]

What is in a parenthesis is processed first and separately
Ex5: TRUE = [TRUE] OR ( [TRUE] AND [FALSE] )
Ex6: FALSE= ( [TRUE] OR [TRUE] ) AND [FALSE]


If you have inner level parenthesis, the deepest ones have precedence :
Ex7: TRUE = [FALSE] OR ( [TRUE] AND ( [TRUE] OR [FALSE] ) )


hope that helps ...

[mshmyob]

Your SQL string has been built wrong.

The & symbols is just conconcates your string.

einSqlStmt = einSqlStmt1 & " IN ('" & vorfilterString & "', NOT '" & vorfilterString1 & "' AND NOT '" & vorfilterString2 & "');"

Notice the single quote as in '" or "'

I didn't look at your Logical operators to see if they are correct just your sysntax of the SQL statement.

cheers,

[Oralloy]

Jaswanth,

What are you trying to accomplish?

Are you trying to build a complex boolean statement, or a series of options in an SQL IN expression? Or, perhaps a combination of both?

Nevertheless, if you are unsure of operator precedence, then use parentheses. Do not even waste time looking it up, as if you do not know it, then the next programmer after you will probably not understand what you wrote, anyway.

Also, if you use parentheses, then there is no ambiguity in the expression at all - simpy put, using parentheses removes the chance of an inadvertent mistake - the code will mean exactly what you want it to.

That said, if you can clarify exactly what you are trying to accomplish, maybe we can help you out with more than vague statements.

Luck!
Oralloy