Add values to your generic ORDA queries

Automatically translated from English

By now you’ve surely noticed that ORDA queries are not only light and readable, they also make it easy to navigate through the entire data model using object-oriented concepts! In this blog post, we showed you how to write powerful and easy-to-maintain queries. One of the methods recommended was providing the query and values separately via placeholders. 4D v17 R5 takes placeholders a step further by allowing you to write generic ORDA queries: say hello to named placeholders for values!

HDI: Example of named placeholders for values in ORDA queries

These new placeholders are provided as object parameters in the query settings. Since an object is a key / value map, it’s very easy to use them in your queries.

An example is worth a thousand words

Here’s a query to get a client named Charlie with Loyal client as a comment. Does this ring any bells? If not, you should check out this post to refresh your memory.

C_OBJECT($clients)
$clients:=ds.Clients.query("name = :1 and comment = :2";"Charlie@";"Loyal client")

The query can also be written as:

C_OBJECT($settings;$clients)
$settings:=New object
$settings.parameters:=New object("givenName";"Charlie@";"givenComment";"Loyal client")
$clients:=ds.Clients.query("name = :givenName and comment = :givenComment";$settings)

Just use the placeholder with its name prefixed by “:” .

Your code is easily readable and maintainable, however, an even greater advantage is being able to write generic queries whose value parameters may come from different sources (a user’s interface or a request).

What about a pattern like this?

You can also provide your users a query interface where they can choose the search criteria and the values to apply.

The code below is for an interface that allows a salesperson to browse a list of their clients. It returns filtered content according to the salesperson’s ID.

C_OBJECT($formData;$settings;$clients)
C_TEXT($queryString)
 
$formData:=New object
DIALOG("QueryEditor";$formData)
CLOSE WINDOW
 
if (OK=1)
 //The logged sales person can only browse their clients
 $queryString:="salesPersonUserId = :givenUserId"
 //The $formData object comes from the user's interface with search criteria filled

 //It contains the sales person's user id and some additional search criterias (name and city)

 $settings:=New object
 $settings.parameters:=$formData
 
 If ($settings.parameters.givenName#Null)
  $queryString:=$queryString+" and name = :givenName"
 End if
 
 If ($settings.parameters.givenCity#Null)
  $queryString:=$queryString+" and city.name = :givenCity"
 End if
 
 $clients:=ds.Clients.query($queryString;$settings)
end if

 

The examples above are querying a dataClass, but if you check the documentation, you’ll see it’s appliable on collections too!

As you can see, building queries dynamically is a piece of cake. Download and run the HDI to learn more!

 

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• Product Owner •

Marie-Sophie Landrieu-Yvert has joined the 4D Product team as a Product Owner in 2017. As a Product Owner, she is in charge of writing the user stories then translating it to functional specifications. Her role is also to make sure that the feature implementation delivered is meeting the customer need.

Marie-Sophie graduated from the ESIGELEC Engineering School and began her career as an engineer at IBM in 1995. She participated on various projects (maintenance or build projects) and worked as a Cobol developer. Then she worked as an UML designer and Java developer. Lately her main roles were analyzing and writing functional requirements, coordinate business and development teams.