The getMainDataSourceAlias placeholder

The getMainDataSourceAlias placeholder is used exclusively in WHERE clauses, and refers to the (USoft-generated) alias of the main data source in the FROM clause.

This placeholder is similar to the getDataSourceAlias and getThisDataSourceAlias placeholders.

Syntax

${getMainDataSourceAlias()}

Example

For a PERSON table with a relationship to itself, the Where Clause property can be set to:

EXISTS(
    SELECT  *
    FROM    PERSON
    RELATE Person "IS FATHER OF" ${getMainDataSourceAlias()}
    WHERE family_name LIKE 'R%'
)

The Page Engine translates this statement to:

SELECT    ID
,         FAMILY_NAME
,         FIRST_NAME
,         'Yes' UseIOFormats
FROM      PERSON t1
WHERE EXISTS (
    SELECT    *
    FROM      PERSON
    RELATE    Person "IS FATHER OF" t1
    WHERE family_name LIKE 'R%'
)

So the getMainDataSourceAlias placeholder is used to point to the t1 alias used for this table.