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"Must provide a field name for parameter" error message

  • 18 February 2022
  • 6 replies
  • 93 views
nikitanaresh

Hi, I’m trying to create a simple parameter to choose between 2 dimensions to breakdown a view. I’ve copied the syntax exactly from the Looker docs, but keep getting an error saying that the “parameter’ needs a field name:

 

parameter: regiondrilldown {
    type: unquoted
    allowed_value: {value: "Country"}
    allowed_value: {value: "State"}
    allowed_value: {value: "City"}
  }

  dimension: geo_breakdown {
    type: string
    label_from_parameter: regiondrilldown
    sql:
      case
        when {% parameter ${regiondrilldown} %} = 'Country' Then ${country}
        when {% parameter ${regiondrilldown} %} = 'State' then ${state}
        when {% parameter ${regiondrilldown} %} = 'City' then ${city}
      end ;;
  }

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Best answer by n_davis 18 February 2022, 17:39

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6 replies

Dawid
Userlevel 7
Badge +1

What if you simplify it this way, provided that your table dimensions are called like that

dimension: geo_breakdown {
    type: string
    label_from_parameter: regiondrilldown
    sql: ${TABLE}.{% parameter regiondrilldown %} ;;
  }

 

That’s because you can’t do

${{% parameter regiondrilldown %}}

 

Dawid
nikitanaresh

Tried that, but I’m still getting the same field name error. 

I’m trying this out on the Qwiklabs ecommerce model. Could it just be an issue with the testing environment?

 

Dawid
Userlevel 7
Badge +1

If you keep the code as you have then you can’t have parameter unquoted as it will produce

Country = "Country"

Unquoted means the value is entered as is and not as string literal

Dawid
N
Userlevel 1

I usually do parameters this way @nikitanaresh 

 

parameter: regiondrilldown {
    type: unquoted
    allowed_value: {value: "country" 
                    label: "Country"}
    allowed_value: {value: "state"}
                    label: "State"}
    allowed_value: {value: "city"}
                    label: "City"}
  }

  dimension: geo_breakdown {
    type: string
    label_from_parameter: regiondrilldown
    sql:
        {% if regiondrilldown._parameter_value == 'country' %} ${country}
        {% elsif regiondrilldown._parameter_value == 'state' %} ${state}
        {% elsif regiondrilldown._parameter_value == 'city' %} ${city}
        {% else %} ${country}
        {% endif %};;
  }

 

Dawid
Userlevel 7
Badge +1

The above is better because the conditional logic is within Liquid, so parameter can be unquoted but you make the paramter’s output to be used in conditional logic in SQL

Dawid
nikitanaresh

This works! I guess I just had my quotes and = vs == mixed up.

I fixed that and it ran with both an if and a case statement.

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