SysQuery::findOrCreateRange() - A better way to create dynamic query ranges

-
When creating dynamic query ranges in X++, it is considered a best practice to create a range only if it has not been already created. I have seen examples of code where the addRange() method is called inside an executeQuery() method. This has a performance hit and should be avoided. The best approach is to create the range in the init() of the datasource. In the executeQuery(), we can find the range first, if it does not exists or has not been created at that point, create a new one and apply the values.

I found a helper method on the SysQuery class which did exactly this. The method is SysQuery::findOrCreateRange(). The method takes two parameters, a datasource to add the range to and the range itself. It returns a range object.

Comments

Post a Comment

Popular posts from this blog

How to add empty ranges in query

-
In Dynamics AX programming, a common mistake I have seen when it comes to query ranges is passing an empty string value to the range. The developer here is expecting it to show all the records where the range field is empty. Instead, what we get is all records without the range being applied. As baffling as it may seems, it is easily explainable. The query engine in Dynamics AX, will not add a range if you don’t specify a value or if you specify an empty string because an empty string is treated as no value. So the following code will result in this SQL statement, query = new Query(); qbds = query.addDataSource(tableNum(ProjTable)); qbr = qbds.addRange(fieldNum(ProjTable, Name)); qbr.value(''); Select first fast * from ProjTable; But what was expected was something like, Select first fast * from ProjTable where Name == ''; So to work around this issue, use the SysQuery::valueEmptyString() static method which parses the empty strings correctly so that it...
Read more

The field with ID '0' does not exist in table - Cause and resolution.

-
Image
Hello readers, In Dynamics AX coding, you should have come across this error sometime - The field with ID '0' does not exist in table 'SomeTable' So what causes this error and what is the possible resolution to it? Well, the most likely cause for this error is a missing mapping in a table map. Let us look at an example. I've a simple Map named CustVendAccount with one Account field. I've created two mappings - one with CustTable's AccountNum field and for the otehr mapping, I just specify VendTable but no field. This is how my map looks like, Now, I've a simple job which just passes either CustTable or VendTable as an argument and then we print the Account field in the map. static void CustVendAccountMap(Args _args) { CustTable custTable; VendTable vendTable; void readMap(CustVendAccount _custVendAccount) { info(strFmt("Value from table %1 is %2",tableId2name(_custVendAccount.TableId), _custV...
Read more

Get selected records in Dynamics AX 2012

-
Image
In my earlier post, we discussed how we can retrieve all selected records on a list page. You can read that post here . Retrieving all selected records from a caller form is very easy. The code for this can be found in a number of places in standard Dynamics AX codebase. The general approach is to use the dataSource.getFirst(1) statement to get the first selected record and loop through the remaining using dataSource.getNext() . In Dynamics AX 2009, a new class was introduced for this purpose. This was the MultiSelectionHelper class. In Dynamics AX 2012, another new class has been introduced to retrieve the selected records. This is the MultiSelectionContext class. The MultiSelectionHelper class is an application class. It presents two constrcutors. The standard constructor method just creates a new instance of the MultiSelectionHelper class. When this construct is used, you will have to explicitly set the dataSource to be used for fethcing selected records. This can be done...
Read more