Parameter
Last updated on
May 06, 2022 08:56:25 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 iterates over each row of a query and calls the closure function to work on row of the query. The returned value will be set at the same index in a new query or the provided result query.
Returns
Modified query.
Category
History
ColdFusion (2021 release): Introduced the following parameters:
- parallel
- maxThreadCount
ColdFusion (2018 release): Introduced named parameters.
New in Adobe ColdFusion (2016 release)
See also
Syntax
queryMap(query, function(row [, currentRow] [, query] ){} [, parallel] [, maxThreadCount])
Parameters
|
|
Description |
|
query |
(Required) The query to be iterated over. |
|
closure |
(Required) Map 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. |
|
template |
(Optional) Define the schema of the returned query. |
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}
]);
qmap=QueryMap(myQuery,function(obj){
if (obj.id>1){
obj.name="Hello " & obj.name
return obj
}
else{
obj.name="Hi " & obj.name
return obj
}
})
writeOutput("The new query is:")
writeDump(qmap)
</cfscript>
Output
Example 2
<cfscript>
qoptions = {result="myresult", datasource="cfbookclub", fetchclientinfo="yes"};
sampleQuery = QueryExecute("select * from books order by bookid", [] ,qoptions);
function mapQuery(any Obj){
if(Obj.ISSPOTLIGHT == "Y")
Obj.TITLE = "NEW: " & Obj.TITLE;
return Obj;
}
newQuery = QueryMap(sampleQuery, mapQuery);
writedump(newQuery);
</cfscript>
The script prefixes “NEW” on Titles that have Spotlight set to “Y”.
Using member function
<cfscript>
myResult=QueryExecute("SELECT * FROM EMPLOYEES",[],{datasource="cfdocexamples"});
myArray=ArrayNew(1);
// Populate myArrray with values "NO"
for (i=1;i<=myResult.recordcount;i++){
myArray[i]="NO";
}
// Add column InSanFrancisco and populate with values of myArray
QueryAddColumn(myResult,"InSanFrancisco","varchar",myArray);
// Iterate through the array and replace values of InSanFrancisco where location is San Francisco
status=myResult.map(function (col){
if (col.LOCATION=="San Francisco")
col.InSanFrancisco = "YES";
return col;
});
WriteDump(status);
</cfscript>
Using parallelization
<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}
]);
qmap=QueryMap(myQuery,function(obj){
if (obj.id>1){
obj.name="Hello " & obj.name
return obj
}
else{
obj.name="Hi " & obj.name
return obj
}
})
writeOutput("The new query is:")
writeDump(qmap)
</cfscript>
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