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- Thread starter Kendo
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Hi there,
Check out and Off the top of my head, I use a combo of CFSCRIPT, short-circuit eval, and plain simple logic I picked up over the years.
(1) Use CFSCRIPTs when you can.
(2) Take advantage of short-circuit evaluation when evaluating two or more expression in conditional statements when you can.
Eg. for 'ANDs' put more likely false expression before others.
if x=3 is less likely than y=5 then write
<CFIF (x EQ 3) AND (y EQ 5)>
blah blah blah...
</CFIF>
It's the reverse for 'ORs' where you put the more likely true expression before others.
(3) Any variable with value other than 0 and 'NO' are evaluated as true if used as an expression. Therefore you do the following:
<CFIF qUsers.Recordcount>
// code here is evaluated query qUsers record count IS NOT 0.
</CFIF>
HTH.
Klotzki
Check out and Off the top of my head, I use a combo of CFSCRIPT, short-circuit eval, and plain simple logic I picked up over the years.
(1) Use CFSCRIPTs when you can.
(2) Take advantage of short-circuit evaluation when evaluating two or more expression in conditional statements when you can.
Eg. for 'ANDs' put more likely false expression before others.
if x=3 is less likely than y=5 then write
<CFIF (x EQ 3) AND (y EQ 5)>
blah blah blah...
</CFIF>
It's the reverse for 'ORs' where you put the more likely true expression before others.
(3) Any variable with value other than 0 and 'NO' are evaluated as true if used as an expression. Therefore you do the following:
<CFIF qUsers.Recordcount>
// code here is evaluated query qUsers record count IS NOT 0.
</CFIF>
HTH.
Klotzki
geofflilley
Programmer
Kendo,
I agree with Klotzki. Some of the tips I use:
1. When you want to check for the existence of a variable, use <cfif isDefined("form.variable"
>. I used to CFPARAM my variables, then check for len, but isDefined is faster.
2. Scope your variables. A local variable would be "variables.variableName"; form variables would be "form.variableName", and so on.
3. When you're doing queries, prefix the column you're selecting with the table name.
<cfquery name="getbooks" datasource="ingram">
select books.title, books.author, books.ISBN
from books
where bookID=<cfqueryparam value="#url.bookID#" cfsqltype="CF_SQL_VARCHAR">
</cfquery>
Two other things I'd like to point out in the above statement:
3a. Don't use "select *"; list out the columns you need.
3b. When you have a WHERE clause that has a variable in it, use CFQUERYPARAM to scope that variable a little more tightly. There's about 8 different types, some of which your DB driver may not support, but at the very least, you can use CF_SQL_VARCHAR and CF_SQL_INTEGER. This is also a security patch.
4. If you have more than 3 possible conditions in a CFIF, put it in a CFCASE statement instead.
That's about all I can think of off the top of my head. HTH.
I agree with Klotzki. Some of the tips I use:
1. When you want to check for the existence of a variable, use <cfif isDefined("form.variable"
>. I used to CFPARAM my variables, then check for len, but isDefined is faster.2. Scope your variables. A local variable would be "variables.variableName"; form variables would be "form.variableName", and so on.
3. When you're doing queries, prefix the column you're selecting with the table name.
<cfquery name="getbooks" datasource="ingram">
select books.title, books.author, books.ISBN
from books
where bookID=<cfqueryparam value="#url.bookID#" cfsqltype="CF_SQL_VARCHAR">
</cfquery>
Two other things I'd like to point out in the above statement:
3a. Don't use "select *"; list out the columns you need.
3b. When you have a WHERE clause that has a variable in it, use CFQUERYPARAM to scope that variable a little more tightly. There's about 8 different types, some of which your DB driver may not support, but at the very least, you can use CF_SQL_VARCHAR and CF_SQL_INTEGER. This is also a security patch.
4. If you have more than 3 possible conditions in a CFIF, put it in a CFCASE statement instead.
That's about all I can think of off the top of my head. HTH.
Just to correct geofflilley, you use:
<CFIF ParameterExists("Form.Variable">
to check if a variable exists.
The existance of a parameter (whether it has been created) and whether it is defined (if the value is null or not) or not are two different things.
Ryan ;-]
<CFIF ParameterExists("Form.Variable"
>to check if a variable exists.
The existance of a parameter (whether it has been created) and whether it is defined (if the value is null or not) or not are two different things.
Ryan ;-]
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