Parameter
Last updated on
Apr 27, 2021 06:03:12 AM GMT
|
Also Applies to ColdFusion
Note:
You can also set the maximum thread count in ColdFusion Administrator. Click Server Settings > Settings and specify the number of threads in Default Maximum Thread Count For Parallel Functions.
Description
This function calls each row of the query provided.
Returns
None
Category
History
ColdFusion (2021 release): Introduced the following parameters:
- parallel
- maxThreadCount
ColdFusion (2016 release): Added the function.
See also
Syntax
queryEach(query, function(row [, currentRow] [, query] ){} [, parallel] [, maxThreadCount])
Parameters
|
|
Description |
|
query |
(Required) Query to be iterated over. |
|
function |
(Required) Function to be called with each row of the query. |
|
parallel |
(Optional) True if you want to enable parallel programming. |
|
maxThreadCount |
(Optional) The number of threads the function can execute. The number of threads must be between 1-50. If the value exceeds 50, there is an exception. |
Example 1
<cfscript>
myQuery = queryNew("id,name,amount","Integer,Varchar,Integer",
[
{id=1,name="One",amount=15},
{id=2,name="Two",amount=18},
{id=3,name="Three",amount=32}
]);
QueryEach(myQuery,function(any obj){
writeOutput(obj.name & "<br/>")
})
</cfscript>
Output
One
Two
Three
Example 2
<cfscript>
qoptions = {result="myresult", datasource="cfbookclub", fetchclientinfo="yes"};
sampleQuery = QueryExecute("select * from books order by bookid", [] ,qoptions);
function printQuery(any Obj){
WriteDump(Obj);
}
WriteOutput("QueryEach: ");
QueryEach(sampleQuery, printQuery);
</cfscript>
The script loops through each item in the query.
Using member function
<cfscript>
myResult=QueryExecute("SELECT * FROM EMPLOYEES",[],{datasource="cfdocexamples"});
// Execute the function to call each row and return the values of Location
myResult.each(function(count){
myList=#count.LOCATION#;
WriteOutput(myList);
});
</cfscript>
Using parallelization- Example 1
<cfscript>
myQuery = queryNew("id,name,amount","Integer,Varchar,Integer",
[
{id=1,name="One",amount=15},
{id=2,name="Two",amount=18},
{id=3,name="Three",amount=32} ,
{id=4,name="Three",amount=32},
{id=5,name="Three",amount=32},
{id=6,name="Three",amount=32},
{id=7,name="Three",amount=32},
{id=8,name="Three",amount=32},
{id=9,name="Three",amount=32},
{id=10,name="Three",amount=32},
{id=11,name="Three",amount=32}
]);
function callbck(any obj){
writeOutput(obj.name & "<br>")
}
QueryEach(myQuery,callbck,true,10)
</cfscript>
<cfscript>
qoptions = {result="myresult", datasource="cfbookclub", fetchclientinfo="yes"};
sampleQuery = QueryExecute("select * from books order by bookid", [] ,qoptions);
function printQuery(any Obj){
Writeoutput(Obj.bookimage & "<br>");
}
WriteOutput("QueryEach: ");
QueryEach(query =sampleQuery,callback= printQuery,parallel=false,maxthreadcount=5);
QueryEach(query =sampleQuery,callback= printQuery,parallel=false);
</cfscript>
<cfscript>
myResult=QueryExecute("SELECT * FROM EMPLOYEES",[],{datasource="cfdocexamples"});
// Execute the function to call each row and return the values of Location
myResult.each(function(count){
myList=#count.LOCATION#;
WriteOutput(myList & "<br>");
},true,10);
</cfscript>
Using parallelization- Example 2
<cfscript>
// Install the package derby before executing this code. cfpm>install derby
qoptions = {result="myresult", datasource="cfbookclub", fetchclientinfo="yes"};
sampleQuery = QueryExecute("select * from books order by bookid", [] ,qoptions);
function printQuery(any Obj){
return Obj;
}
t_start=GetTickCount()
QueryEach(query =sampleQuery,callback= printQuery,parallel=true,maxthreadcount=50)
t_end=GetTickCount()
writeoutput("<br>Time taken with 50 threads:" & t_end-t_start)
</cfscript>
Using parallelization- Example 3
<cfscript>
myResult=QueryExecute("SELECT * FROM EMPLOYEES",[],{datasource="cfdocexamples"});
// Execute the function to call each row and return the values of Location
t_start=GetTickCount()
myResult.each(function(count){
myList=#count.LOCATION#;
WriteOutput(myList);
},true,50)
t_end=GetTickCount()
writeOutput("<br>Time taken with 50 threads:" & t_end-t_start)
</cfscript>
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