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Expression Fields in Advanced views

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12-06-2021 06:09 PM
AdministradorData_Gis
by
New Contributor II
‎12-06-2021 06:09 PM

Hi everyone,

I am trying to create an advanced view according to this documentation Advanced views , this is my code:

{
  "layers": [
    {
      "name": "VistaAvanzada",
      "description": "AttributeJoin",
      "adminLayerInfo": {
        "viewLayerDefinition": {
          "table": {
            "name": "target",
            "sourceServiceName": "TestJoinExpression_Tabla1",
            "sourceLayerId": 0,
            "sourceLayerFields": [
              {
                "name": "key1",
                "alias": "key1",
                "source": "key1"
              },
              {
                "name": "date1",
                "alias": "date1",
                "source": "date1"
              }
            ],
            "relatedTables": [
              {
                "name": "joined",
                "sourceServiceName": "TestJoinExpression_Tabla2",
                "sourceLayerId": 0,
                "sourceLayerFields": [
                  {
                    "name": "key1related",
                    "alias": "key1related",
                    "source": "key1related"
                  },
                  {
                    "name": "name",
                    "alias": "name",
                    "source": "name"
                  },
                  {
                    "name": "relatedExpression",
                    "alias": "SumNumsTest",
                    "expression": "Num1 + Num2",
                    "type": "esriFieldTypeInteger"
                  }
                ],
                "type": "INNER",
                "parentKeyFields": [
                  "key1",
                  "key2"
                ],
                "keyFields": [
                  "key1related",
                  "key2related"
                ]
              }
            ]
          }
        }
      }
    }
  ]
}

For this test, I have created the fields Num1 and Num2, in both tables, because I am not sure how the expression works, however the expression field "relatedExpression" is not created, I can see the fields I declared, coming from both tables. That is, the view works for me as a union of tables, but I cannot create the additional field that corresponds to the expression.

I appreciate the help

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1 Reply
ponlawat_w
by
New Contributor
‎04-04-2023 07:21 PM

It has been 2 years so I am not sure if you already have it fixed yet, but I got it solved by adding "source" property to field object referring to at least one field whose value being used in the expression, then the field displayed normally.

Example:

[
  { // calculate value on single field
    "name": "testField",
    "type": "esriFieldTypeInteger",
    "alias": "testField",
    "expression": "myNumberField1 * 2",
    "source": "myNumberField1"
  },
  { // calculate value on multiple fields, only one field needed in source
    "name": "testField2",
    "type": "esriFieldTypeInteger",
    "alias": "testField2",
    "expression": "myNumberField1 + myNumberField2",
    "source": "myNumberField1"
  },
  { // calculate static value for all records, source field must be there even it is irrelevant
    "name": "testField3",
    "type": "esriFieldTypeString",
    "alias": "testField3",
    "expression": "'Hello World!'",
    "source": "OBJECTID"
  },
  { // example of advanced SQL to get hour part from date field
    "name": "hourOfDay",
    "type": "esriFieldTypeInteger",
    "alias": "hourOfDay",
    "expression": "DATEPART(HOUR, myDateField)",
    "source": "myDateField"
  }
]

 

Hope this helps.

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