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CASE Expression

A CASE expression defines branching logic. It evaluates conditions in sequence and returns the corresponding result for the first condition that matches. If no condition applies, an optional fallback ($else) value is used.

$case​

Added in: indicate.dsl.dql@1.0.0
A conditional expression with one or more $cases, each containing a condition and a result. An optional $else defines the fallback result if no condition matches.

{
  "$case": {
    "$cases": [
      {
        "$condition": Object ( LogicalExpression ),
        "$expr": Object ( Expression )
      }
    ],
    "$else": Object ( Expression )
  }
}
note
  • $cases are evaluated in order; the first $condition that evaluates to true determines the result.
  • $else is optional. If no condition matches and no $else is provided, the result will be NULL.
  • All $expr return values should ideally share a common type or be coercible to a shared supertype.
  • You can nest $case expressions inside other expressions for more complex logic.
Example: 
{
  "$case": {
    "$cases": [
      {
        "$condition": {
          "$binary": {
            "$fn": "equals",
            "$left": { "$identifier": "status" },
            "$right": { "$scalar": "active" }
          }
        },
        "$expr": { "$scalar": 1 }
      },
      {
        "$condition": {
          "$binary": {
            "$fn": "equals",
            "$left": { "$identifier": "status" },
            "$right": { "$scalar": "inactive" }
          }
        },
        "$expr": { "$scalar": 0 }
      }
    ],
    "$else": { "$scalar": -1 }
  }
}