Form data source link types - Active, Delay, Passive, Inner join, Outer join, Exist join, Not exist join

Form data source link types

Form data source link type is a property of the form data source. We can add more than one tables as a data source to the form. Those data sources should has the table level relation, So, then the developer no need to work on the coding part to find the relation records. For example, if we create the order form, that order form has orders and order details tables as form datasources. We can add both tables as a data sources to the form.

The parent table and child table should has the table relation. So, once we add these tables in the form as data sources. We can select the child table data source and mention the parent table name in the join source property of the child table form data source property.

Example:

Here, I have created two tables Hari_Order and Hari_OrderDetails. Hari_OrderDetails has the foreign key of Hari_Order table Key is OrderNo.

Hari_Order table

Order No	Customer Name
Ord 2	Ram
Ord 1	Hari
Ord 3	Vithyaa
Ord 4	Uma

Hari_OrderDetails

Order No	Product Name	Product Description
Ord 1	Prod 1	Product One
Ord 1	Prod 2	Product Two
Ord 1	Prod 3	Product Three
Ord 2	Prod 1	Product One
Ord 2	Prod 2	Product Two
Ord 3	Prod 1	Product One

Set the join source and set the link type

Table relation

Use join source and link type

Active

Active link type update the child data sources without any delay when you select the parent table record. When you deal with more records it will be affect application performance.

Delay

Delay form data source link type is also same as active method the different is delay method won't update immediately when you select the parent record. It will update the child data source when you select the parent table, Ax use pause statement before update the child data source. For example, if we are dealing with lot of records so, when the user click or scroll the order, order details will update without any delay if we use active method.

So, We can use delay method because of performance improvement.

Passive

Passive form data source link type won't update the child data source automatically. For example if we select the parent table order then order details child data source won't update. If we need to update the child data source we need to call the child data source execute query method by program (code).

The order details grid is empty. If we need populate the child data source (order details) then we need to call the Hari_OrderDetails_ds.executeQuery() method in the parent table Hari_Order form data source active method. We can add separate button "Populate order details" and call the code Hari_OrderDetails_ds.executeQuery(). So, if the user need to see the order details then the user update by click the "Populate order details" button.

Inner join

Inner join form data source link type displays the rows that match with parent table and child table. For example if the order doesn't has any order details then the order will not be display.

Here, Order 4 does not has the order details records, so it is not coming in the order grid.

Outer join

Outer join form data source link type will return all parent records and matched child records. It will return all rows in the parent table. Here, Order 4 doesn't has the child records (order details) but it is populating in the order grid. It is the difference between inner join and outer join.

Here, Order 4 is coming even order 4 does not has the order details.

Exist join

Exist join form data source link type return matched rows of the parent table. It behaves like inner join but the different is once parent row matched with child records then stop the process and update in the grid, Ax won't consider how many records in child table for the parent row.

Here, Order 4 is not coming because Order 4 does not has the order details.

Not exist join

Not exist join form data source link type is totally opposite method to exist join. It will return the not matched parent records with child records.

Here, Order 4 is coming because order 4 does not has the order details.

Each form data source link type has different behavior. Active, Delay and Passive are one category and Inner join, Outer join, Exist join, Not exist join are another category. So, please understand the behavior and choose the link type based on your requirement.

Thanks,

Hari

Form datasource

What is form datasource

Form datasource is a data source (source) of the form. The forms are displaying the database table records to the end user by using the form datasource. For example, if you open the vendor list screen, the form will display the vendors list by fetching records from the database VendTable table. Here VendTable is the form datasource.

The form displays the datasource fields. Type of form datasources are AOT query, table and view. The form has two types of controls that are bound controls and unbound controls. Bound controls are linked with form datasource fields, but unbound controls are not related with form datasource fields. The form datasources are having link with database. So, it is having connection with database. It supports form to add, edit and delete the records.

Types of form datasources

1. AOT Query
2. Tables
3. Views

Add datasource to the form

In AX, It is very easy to display or update or delete the records in forms. It is very simple. Follow the below steps to display the records in the grids.

1. Add new form
2. Click and drag a table to form datasource node or right click on the form datasource and click new datasource and select the table name in table property of the newly added form datasource
3. Add grid control in the form design node
4. Click and drag the newly added form datasource table fields to grid control

We can control the forms to add, edit and delete the form datasource records by using the AllowCreate, AllowEdit and AllowDelete form datasource properties. For example, if you want to only display the records but don’t allow the user to create, update and delete the records then please set “No” value to the form datasource properties AllowCreate, AllowEdit and AllowDelete.

Please refer the below screenshot

Method overloading in Ax 2012

Method overloading:

Method overloading is the one of the oops concept. Method overloading is same method name but different parameters or different parameter data types in a class.

For example:

Private real GetSalary(int empId)

{

…………….

}

Private real GetSalary(int empId, boolean plusBonus)

{

……

}

The above methods are same name “GetSalary” but parameters are different. We can call this method like below

salaryAmount = GetSalary(3426);

or

salaryAmount = GetSalary(3426, true);

Unfortunately, X++ does n’t support method overloading, but it supports options parameters. The optional parameter mimics like method overloading. In X++ we can do the above business logic like below code by using optional parameters.

Private real GetSalary(int empId, boolean plusBonus = false)

{

……………

}

Here, plusBonus variable is the optional parameters.

We can call the above method like below code

salaryAmount = GetSalary(3426); // The default value “False” will be set to plusBonus parameter

or

salaryAmount = GetSalary(3426, true);

We can order optional parameters to end parameter(s). In other words the optional parameters should be placed end to the non optional parameters. We can't place non optional parameters next to optional parameters. For your reference please refer the below code. The below code is not supported.

Private real GetSalary(boolean plusBonus = false, int empId)

{

……………

}

Note: C# supports both method overloading and optional parameter concepts.