Indexes outside of ​.NET framework

The following examples are in Python and JavaScript.

Simple indexes

When the .NET SdsTypeBuilder is unavailable, you must build indexes manually.

The following examples show SdsTypes defined in Python and JavaScript. For samples in other languages, go to CONNECT data services code samples in GitHub.

To build an SdsType representation of sample classes in Python and JavaScript, see Sample below:

class State(Enum):

Ok = 0

Warning = 1

Alarm = 2

class Simple(object):

Time = property(getTime, setTime)

def getTime(self):

return self.__time

def setTime(self, time):

self.__time = time

State = property(getState, setState)

def getState(self):

return self.__state

def setState(self, state):

self.__state = state

Measurement = property(getValue, setValue)

def getValue(self):

return self.__measurement

def setValue(self, measurement):

self.__measurement = measurement

var State =

{

Ok: 0,

Warning: 1,

Alarm: 2

}

var Simple = function () {

this.Time = null;

this.State = null;

this.Value = null;

}

Sample

The following code is used to build an SdsType representation of the sample class above.

# Create the properties

# Time is the primary index

time = SdsTypeProperty()

time.Id = "Time"

time.Name = "Time"

time.IsKey = True

time.SdsType = SdsType()

time.SdsType.Id = "DateTime"

time.SdsType.Name = "DateTime"

time.SdsType.SdsTypeCode = SdsTypeCode.DateTime

# State is not a pre-defined type. An SdsType must be defined to represent the enum

stateTypePropertyOk = SdsTypeProperty()

stateTypePropertyOk.Id = "Ok"

stateTypePropertyOk.Measurement = State.Ok

stateTypePropertyWarning = SdsTypeProperty()

stateTypePropertyWarning.Id = "Warning"

stateTypePropertyWarning.Measurement = State.Warning

stateTypePropertyAlarm = SdsTypeProperty()

stateTypePropertyAlarm.Id = "Alarm"

stateTypePropertyAlarm.Measurement = State.Alarm

stateType = SdsType()

stateType.Id = "State"

stateType.Name = "State"

stateType.Properties = [ stateTypePropertyOk, stateTypePropertyWarning,\

stateTypePropertyAlarm ]

state = SdsTypeProperty()

state.Id = "State"

state.Name = "State"

state.SdsType = stateType

# Measurement property is a simple non-indexed, pre-defined type

measurement = SdsTypeProperty()

measurement.Id = "Measurement"

measurement.Name = "Measurement"

measurement.SdsType = SdsType()

measurement.SdsType.Id = "Double"

measurement.SdsType.Name = "Double"

# Create the Simple SdsType

simple = SdsType()

simple.Id = str(uuid.uuid4())

simple.Name = "Simple"

simple.Description = "Basic sample type"

simple.SdsTypeCode = SdsTypeCode.Object

simple.Properties = [ time, state, measurement ]

// Time is the primary key

var timeProperty = new SdsObjects.SdsTypeProperty({

"Id": "Time",

"IsKey": true,

"SdsType": new SdsObjects.SdsType({

"Id": "dateType",

"SdsTypeCode": SdsObjects.SdsTypeCodeMap.DateTime

})

});

// State is not a pre-defined type. SdsType must be defined to represent the enum

var stateTypePropertyOk = new SdsObjects.SdsTypeProperty({

"Id": "Ok",

"Value": State.Ok

});

var stateTypePropertyWarning = new SdsObjects.SdsTypeProperty({

"Id": "Warning",

"Value": State.Warning

});

var stateTypePropertyAlarm = new SdsObjects.SdsTypeProperty({

"Id": "Alarm",

"Value": State.Alarm

});

var stateType = new SdsObjects.SdsType({

"Id": "State",

"Name": "State",

"SdsTypeCode": SdsObjects.SdsTypeCodeMap.Int32Enum,

"Properties": [stateTypePropertyOk, stateTypePropertyWarning,

stateTypePropertyAlarm, stateTypePropertyRed]

});

// Value property is a simple non-indexed, pre-defined type

var valueProperty = new SdsObjects.SdsTypeProperty({

"Id": "Value",

"SdsType": new SdsObjects.SdsType({

"Id": "doubleType",

"SdsTypeCode": SdsObjects.SdsTypeCodeMap.Double

})

});

// Create the Simple SdsType

var simpleType = new SdsObjects.SdsType({

"Id": "Simple",

"Name": "Simple",

"Description": "This is a simple Sds type",

"SdsTypeCode": SdsObjects.SdsTypeCodeMap.Object,

"Properties": [timeProperty, stateProperty, valueProperty]

});

The Time property is identified as the primary index by defining its SdsTypeProperty as follows:

• Indexes outside of .NET framework

  # Time is the primary index

  time = SdsTypeProperty()

  time.Id = "Time"

  time.Name = "Time"

  time.IsKey = True

  time.SdsType = SdsType()

  time.SdsType.Id = "DateTime"

  time.SdsType.Name = "DateTime"

  time.SdsType.SdsTypeCode = SdsTypeCode.DateTime

  // Time is the primary index

  var timeProperty = new SdsObjects.SdsTypeProperty({

  "Id": "Time",

  "IsKey": true,

  "SdsType": new SdsObjects.SdsType({

  "Id": "dateType",

  "SdsTypeCode": SdsObjects.SdsTypeCodeMap.DateTime

  })

  });

Note that the time.IsKey field is set to true.

To read data using the index, you define a start index and an end index. For DateTime, use the ISO 8601 representation of dates and times. To query for a window of values between January 1, 2010 and February 1, 2010, define indexes as “2010-01-01T08:00:00.000Z†and “2010-02-01T08:00:00.000Z†, respectively.

For additional information, see Read data.

Secondary indexes

Secondary indexes are defined at the stream level. To create a stream using the Simple class and adding a secondary index on the Measurement, use the previously defined type. Then create SdsStreamIndex specifying the Measurement property and define a stream identifying the Measurement as the secondary index as shown in the following example.

• Indexes outside of .NET framework

  # Create the properties

  measurementIndex = SdsStreamIndex()

  measurementIndex.SdsTypePropertyId = measurement.Id

  stream = SdsStream()

  stream.Id = str(uuid.uuid4())

  stream.Name = "SimpleWithSecond"

  stream.Description = "Simple with secondary index"

  stream.TypeId = simple.Id

  stream.Indexes = [ measurementIndex ]

  var measurementIndex = new SdsObjects.SdsStreamIndex({

  "SdsTypePropertyId": valueProperty.Id

  });

  var stream = new SdsObjects.SdsStream({

  "Id": "SimpleWithSecond",

  "Name": "SimpleWithSecond",

  "Description": "Simple with secondary index",

  "TypeId": simpleTypeId,

  "Indexes": [ measurementIndex ]

  });

Compound indexes

Consider the following Python and JavaScript types.

• Indexes outside of .NET framework

  class Simple(object):

  # First-order index property

  Time = property(getTime, setTime)

  def getTime(self):

  return self.__time

  def setTime(self, time):

  self.__time = time

  State = property(getState, setState)

  def getState(self):

  return self.__state

  def setState(self, state):

  self.__state = state

  Measurement = property(getValue, setValue)

  def getValue(self):

  return self.__measurement

  def setValue(self, measurement):

  self.__measurement = measurement

  class DerivedCompoundIndex(Simple):

  # Second-order index property

  @property

  def Recorded(self):

  return self.__recorded

  @Recorded.setter

  def Recorded(self, recorded):

  self.__recorded = recorded

  var Simple = function () {

  this.Time = null;

  this.State = null;

  this.Value = null;

  }

  var DerivedCompoundIndex = function() {

  Simple.call(this);

  this.Recorded = null;

  }

To turn the simple type shown in the example into a type supporting the DerivedCompoundIndex type with a compound index based on the Simple.Time and DerivedCompoundIndex.Recorded, extend the type as shown in the following example.

• Indexes outside of .NET framework

  # We set the order for this property. The order of the first property defaulted to 0

  recorded = SdsTypeProperty()

  recorded.Id = "Recorded"

  recorded.Name = "Recorded"

  recorded.IsKey = True

  recorded.Order = 1

  recorded.SdsType = SdsType()

  recorded.SdsType.Id = "DateTime"

  recorded.SdsType.Name = "DateTime"

  recorded.SdsType.SdsTypeCode = SdsTypeCode.DateTime

  # Create the Derived SdsType

  derived = SdsType()

  derived.Id = str(uuid.uuid4())

  derived.Name = "Compound"

  derived.Description = "Derived compound index sample type"

  derived.BaseType = simple

  derived.SdsTypeCode = SdsTypeCode.Object

  derived.Properties = [ recorded ]

  // We set the order for this property. The order of the first property defaulted to 0

  var recordedProperty = new SdsObjects.SdsTypeProperty({

  "Id": "Recorded",

  "Name": "Recorded",

  "IsKey": true,

  "Order": 1,

  "SdsType": new SdsObjects.SdsType({

  "Id": "DateTime",

  "Name": "DateTime",

  "SdsTypeCode": SdsObjects.SdsTypeCodeMap.DateTime

  })

  });

  // Create the Derived SdsType

  var derivedType = new SdsObjects.SdsTyp({

  "Id": "Compound",

  "Name": "Compound",

  "Description": "Derived compound index sample type",

  "BaseType": simpleType,

  "SdsTypeCode": SdsObjects.SdsTypeCodeMap.Object,

  "Properties": [recordedProperty]

  });

  Data in the stream will be ordered as shown in the following table.

  Time	Recorded	Measurement
  01:00	00:00	0
  01:00	01:00	2
  01:00	14:00	5
  02:00	00:00	1
  02:00	01:00	3
  02:00	02:00	4
  02:00	14:00	6

  If the Order parameters were reversed with Recorded set to 0 and Time set to 1, the results would be sorted as shown in the following table.

  Time	Recorded	Measurement
  01:00	00:00	0
  02:00	00:00	1
  01:00	01:00	2
  02:00	01:00	3
  02:00	02:00	4
  01:00	14:00	5
  02:00	14:00	6