USMeta.Constraints

note

This article is about the Constraints method of the USMeta internal component.

USMeta.Constraints

At runtime, gets metadata information about constraints from the model developed in USoft Definer. For each retrieved constraint, this information takes the form of name/value pairs. Each name/value pair expresses a constraint attribute setting.

Returns an XML document of the form demonstrated in Example 1 below.

Syntax

SELECT USMeta.Constraints(
*constraint-name-pattern*         Constraints
,      *message-pattern*                 Message
,      *transition-table-pattern*        TransitionTable
,      *mime-type*                       MimeType
)

*mime-type*   :=  {  application/xml
                ,  xml
                ,  application/json
                ,  json  }

All parameters are optional. Parameter values that you pass are mapped to parameters by alias name. The 'ID' value in the following example is for constraint-name-pattern because of the "Constraints" alias:

SELECT   USMeta.Constraints( 'ID' Constraints )

tip

For backward compatibility only, it is possible to supply parameter values by position. Using this syntax, a list of non-aliased values maps to the parameter list in the order stated, with empty values at the end of the list if you supply less than 3 values, and '' (the empty string) as a way of explicitly declaring an empty value.

Constraint-name-pattern is a regular expression that matches zero, one or more constraint names in the model. The result data is limited to constraints matching the pattern. If constraint-name-pattern is omitted, then result data is not limited in this way.

Message-pattern is a regular expression that matches zero, one or more messages of constraints in the model. The result data is limited to constraints with a message matching the pattern. If message-pattern is omitted, then result data is not limited in this way.

Transition-table-pattern is a regular expression that matches zero, one or more names of transition tables of constraints in the model. The result data is limited to constraints with a transition table whose name matches the pattern. If transition-table-pattern is omitted, then result data is not limited in this way.

Mime-type determines whether the output is in XML ( ‘application/xml‘ or 'xml’) or in JSON ('application/json’ or 'json’). The default is XML.

Example 1

This example returns constraint information about any constraints in the model that have a message containing the word 'correct' :

SELECT USMeta.Constraints('.*correct.*' Message)

The return value of this statement could be:

<?xml version="1.0" encoding="UTF-16"?>
<Meta>
   <Constraints>
      <Constraint NAME="STARTDATE_RETURNDATE" MODULE_NAME="TRAVEL" ACTIVE="Y" CORRECT="Y"
         MESSAGE="Return date corrected to match preset number of days for tour." DRIVING_TABLE="TOUR" FIRE_DEFFERED="NONE"
         TRANSITION_TABLE="" TRANSITION_ALIAS="" ON_INSERT="ALWAYS FIRE" ON_DELETE="ALWAYS FIRE" ON_UPDATE="USED COLUMNS FIRE"
         HELP_TOPIC="0" DYNAMIC="1"/>
   </Constraints>
</Meta>

Example 2

This example returns constraint information about all constraints containing the word 'DATE' that have a Transition Table:

SELECT USMeta.Constraints(
    '.*DATE'            Constraints
,   '^(?!\s*$).+'       TransitionTable
)

The return value of this statement could be:

<?xml version="1.0" encoding="UTF-16"?>
<Meta>
   <Constraints>
      <Constraint NAME="CHANGE_PLAN_DATE" MODULE_NAME="TRAVEL" ACTIVE="Y" CORRECT="Y" MESSAGE="" DRIVING_TABLE="TOUR"
          FIRE_DEFFERED="NONE" TRANSITION_TABLE="TOUR" TRANSITION_ALIAS="" ON_INSERT="NEVER FIRE" ON_DELETE="NEVER FIRE"
          ON_UPDATE="USED COLUMNS FIRE" HELP_TOPIC="0" DYNAMIC="1"/>
      <Constraint NAME="NUMDAYS_RETURNDATE" MODULE_NAME="TRAVEL" ACTIVE="Y" CORRECT="Y"
          MESSAGE="The number of days of a tour programme cannot be changed once tours for that destination and type have been scheduled."
          DRIVING_TABLE="TOUR_PROGRAMME" FIRE_DEFFERED="NONE" TRANSITION_TABLE="TOUR_PROGRAMME" TRANSITION_ALIAS="TP"
          ON_INSERT="NEVER FIRE" ON_DELETE="NEVER FIRE" ON_UPDATE="USED COLUMNS FIRE" HELP_TOPIC="0" DYNAMIC="0"/>
   </Constraints>
</Meta>