How much to Query when displaying a few rows at a time in a read-only grid?

dannyh0001 over 5 years ago

Suppose I have a database table 100,000 entries large, and I want to display them in a read-only grid 25 at a time.

How can I achieve this, without having to query everything at once?

It seems that if I query using the page size (here, 25) then the read-only grid does not have an arrow allowing you to move to the next page, presumably because it thinks it is displaying everything. However, since the read-only grid does not have a totalCount parameter, I am unsure of how I can tell the read-only grid that there are still more rows to be queried and displayed.

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Hrishikesh Dixit
Certified Lead Developer
over 5 years ago

You can use the manual paging option in the grid field configuration.
Refer the tutorial given in (Manual paging section)- docs.appian.com/.../read-only-grid-configuration.html

Basically, create a local!pagingInfo with start Index 1 and batch size of 25. In the load section write a query entity to query first 25 records and display them in the grid. Use the pagingSaveInto in the a!gridField to save the updated local!pagingInfo and then re-query next datasubset based on this pagingInfo
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Peter Lewis

Appian Employee

over 5 years ago in reply to Hrishikesh Dixit

Manual paging shouldn't be necessary in this case - the standard method of adding the query to the data parameter and using fv!pagingInfo should allow you to query 25 items at a time.

Here's an example:

a!gridField(
    label: "Read-only Grid",
    labelPosition: "ABOVE",
    data: a!queryEntity(
      entity: cons!EMPLOYEE_ENTITY,
      query: a!query(
        selection: a!querySelection(
          columns: {
            a!queryColumn(
              field: "id"
            ),
            a!queryColumn(
              field: "firstName"
            ),
            a!queryColumn(
              field: "lastName"
            ),
            a!queryColumn(
              field: "department"
            ),
            a!queryColumn(
              field: "startDate"
            )
          }
        ),
        pagingInfo: fv!pagingInfo
      ),
      fetchTotalCount: true
    ),
    columns: {
      a!gridColumn(
        label: "First Name",
        sortField: "firstName",
        value: fv!row.firstName
      ),
      a!gridColumn(
        label: "Last Name",
        sortField: "lastName",
        value: fv!row.lastName
      ),
      a!gridColumn(
        label: "Department",
        sortField: "department",
        value: fv!row.department
      ),
      a!gridColumn(
        label: "Start Date",
        sortField: "startDate",
        value: fv!row.startDate,
        align: "END"
      )
    },
    pagesize: 25,
    initialsorts: {
      a!sortInfo(
        field: "lastName",
        ascending: true
      )
    }
)

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Peter Lewis

Appian Employee

over 5 years ago in reply to Hrishikesh Dixit

Manual paging shouldn't be necessary in this case - the standard method of adding the query to the data parameter and using fv!pagingInfo should allow you to query 25 items at a time.

Here's an example:

a!gridField(
    label: "Read-only Grid",
    labelPosition: "ABOVE",
    data: a!queryEntity(
      entity: cons!EMPLOYEE_ENTITY,
      query: a!query(
        selection: a!querySelection(
          columns: {
            a!queryColumn(
              field: "id"
            ),
            a!queryColumn(
              field: "firstName"
            ),
            a!queryColumn(
              field: "lastName"
            ),
            a!queryColumn(
              field: "department"
            ),
            a!queryColumn(
              field: "startDate"
            )
          }
        ),
        pagingInfo: fv!pagingInfo
      ),
      fetchTotalCount: true
    ),
    columns: {
      a!gridColumn(
        label: "First Name",
        sortField: "firstName",
        value: fv!row.firstName
      ),
      a!gridColumn(
        label: "Last Name",
        sortField: "lastName",
        value: fv!row.lastName
      ),
      a!gridColumn(
        label: "Department",
        sortField: "department",
        value: fv!row.department
      ),
      a!gridColumn(
        label: "Start Date",
        sortField: "startDate",
        value: fv!row.startDate,
        align: "END"
      )
    },
    pagesize: 25,
    initialsorts: {
      a!sortInfo(
        field: "lastName",
        ascending: true
      )
    }
)

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