008 VANTIQRulesandProcedures V30Vantiq资源

1、VANTIQ Rules and ProceduresVANTIQ Training Module 008MODULE OBJECTIVESBy the end of this module, you should be able to:Understand VAIL RulesUnderstand VAIL ProceduresUnderstand how to define VAIL rules/procedures2PROCEDURESyntax:PROCEDURE.()WITH properties = Example:PROCEDURE changeSalary(empName, n

2、ewSalary DEFAULT 1000)your code herereturn “success” 3RETURN?RETURN may be used to explicitly specify the returned value?Procedures return a value when their execution completes.?If not RETURN statement is defined then the value of the last statement in the procedure is returned?RETURN statement MUS

3、T be the last statement in the procedure body ?Example?RETURN This string will be the return value for the procedure4CALLING A PROCEDURE?In VAIL (Rule or Procedure)?changeSalary(David)?or?EXECUTE changeSalary(“David”)?Or use the UI:5PROCEDURE PARAMETERS?You can optionally declare the parameter types

4、.?Allowable types: String, Integer, Real, DateType, Decimal, Currency, GeoJSON, ResourceReference, Object (plus ARRAYs of the above)?Example:?PROCEDURE changeSalary(empName String, newSalary Currency)? your code here?return “success”6PARAMETERS DESCRIPTIONS?You can also add descriptions to your para

5、meters?Used by UI only?Example:?PROCEDURE changeSalary(empName String description Full name (first last),?newSalary Currency description annual salary)7PARAMETERS UI EXAMPLEProcedure Parameter Description8RULE STATEMENTThe rule statement is the first statement in a rule definition and it gives its n

6、ame. Full Syntax:RULE : WHERE ACTIVATIONCONSTRAINT Basic Syntax:RULE Examples:RULE onInsertOrder WHEN INSERT OCCURS ON Order9ACTIVATION CONSTRAINTThe activation contraint determines when the rule should fire. The activation contraint starts with WHEN or BEFORE. WHEN Syntax:WHEN INSERT | UPDATE | DEL

7、ETE OCCURS ON AS WHERE WHEN MESSAGE ARRIVES FROM AS WHERE WHEN PUBLISH OCCURS ON AS WHERE 10ACTIVATION CONSTRAINT EXAMPLESWHEN INSERT OCCURS ON SensorWHEN INSERT OCCURS ON Sensor WHERE Sensor.reading 100WHEN INSERT OCCURS ON Sensor AS tempSensorWHERE tempSensor 100AND tempSensor.sensorType=“temp”WHE

8、N UPDATE OCCURS ON Patient AS pWHERE patient.location = “Hospital”11MORE ACTIVATION CONSTRAINTS EXAMPLESWHEN MESSAGE ARRIVES FROM ”MQTT_topic AS msgWHEN PUBLISH OCCURS ON /sensorData AS sensor12RULE BODY (DATA RULES)In the case of rules that trigger of data, rules can use the data referenced directl

9、y in the body of the rule.RULE onInsert_simpleWHEN INSERT OCCURS ON Simple as sIF (s.msg = “test”)13RULE BODY (MESSAGE/PUBLISH RULES)In the case of rules that trigger off a topics, the message contains the data in a ”newValue” attribute e.g. topic: /VoltageReading/new, newValue: sensorId: SampleIden

10、tifier, reading: 12.35 RULE onPublish_testWHEN PUBLISH OCCURS ON “/test” AS mIF (m.newValue.msg = “test)14RULES COMPLETE EXAMPLERULE myFirstRule WHEN INSERT OCCURS ON Order AS order FOR mgr IN SELECT ONE * FROM Employee WHERE name = order.salesPersonManager Search for manager for sales person PUBLIS

11、H message: There is an order for your review: + order.orderId TO SOURCE corporateEmail USING recipients: mgr.emailAddress IF (order.customerName = myFavoriteCustomer) applyDiscount(10%, order) Email manager to review orderExecute “applyDiscount” if “myFavoriteCustomer”15RULE ACTIVATION VERSUS RULE B

12、ODYWhat is the difference between the following rules?RULE onInsert_withActivationWHEN INSERT OCCURS on Sensor WHERE Sensor.temp100doSomething(Sensor.sensorId)ANDRULE onInsert_withIfWHEN INSERT OCCURS on SensorIF (Sensor.temp100) doSomething(Sensor.sensorId)16FURTHER THOUGHT ON ACTIVATIONRULE onInse

13、rt_tempWHEN INSERT OCCURS on Sensor WHERE Sensor.type=“temp”doSomething(Sensor.sensorId)RULE onInsert_vibrationWHEN INSERT OCCURS on Sensor WHERE Sensor.type=“vibration”doSomethingElse(Sensor.sensorId)RULE onInsert_withIfWHEN INSERT OCCURS on SensorIF (Sensor.type=“temp” doSomething(Sensor.sensorId) ELSE IF (