Add percent_rank presto function (#1988)

* Add percent_rank presto function * Spell percent correctly
malloydata · Oct 31, 2024 · 0b95c39 · 0b95c39
1 parent 9948842
commit 0b95c39
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diff --git a/packages/malloy/src/dialect/trino/dialect_functions.ts b/packages/malloy/src/dialect/trino/dialect_functions.ts
@@ -227,6 +227,12 @@ const to_unixtime: DefinitionBlueprint = {
   impl: {function: 'TO_UNIXTIME'},
 };
 
+const percent_rank: DefinitionBlueprint = {
+  takes: {},
+  returns: {calculation: 'number'},
+  impl: {function: 'PERCENT_RANK', needsWindowOrderBy: true},
+};
+
 export const TRINO_DIALECT_FUNCTIONS: DefinitionBlueprintMap = {
   // aggregate functions
   approx_percentile,
@@ -254,4 +260,7 @@ export const TRINO_DIALECT_FUNCTIONS: DefinitionBlueprintMap = {
   regexp_like,
   regexp_replace,
   to_unixtime,
+
+  // window functions
+  percent_rank,
 };
diff --git a/test/src/databases/presto-trino/presto-trino.spec.ts b/test/src/databases/presto-trino/presto-trino.spec.ts
@@ -232,6 +232,46 @@ describe.each(runtimes.runtimeList)(
         m2 is min_by(y, x)
       }`).malloyResultMatches(runtime, {m1: 55, m2: 100});
     });
+
+    it(`runs the percent_rank function - ${databaseName}`, async () => {
+      await expect(`# debug
+          run: ${databaseName}.sql(
+            """
+                      SELECT 55 as x
+            UNION ALL SELECT 22 as x
+            UNION ALL SELECT 1 as x
+            """
+          ) -> {
+            group_by: x
+            order_by: x desc
+            calculate: pctrnk is percent_rank()
+          }
+        `).malloyResultMatches(runtime, [
+        {x: 55, pctrnk: 0},
+        {x: 22, pctrnk: 0.5},
+        {x: 1, pctrnk: 1},
+      ]);
+    });
+
+    it(`runs the percent_rank function with order_by - ${databaseName}`, async () => {
+      await expect(`# debug
+        run: ${databaseName}.sql(
+          """
+                    SELECT 55 as x
+          UNION ALL SELECT 22 as x
+          UNION ALL SELECT 1 as x
+          """
+        ) -> {
+          group_by: x
+          order_by: x desc
+          calculate: pctrnk is percent_rank() { order_by: x asc }
+        }
+        `).malloyResultMatches(runtime, [
+        {x: 55, pctrnk: 1},
+        {x: 22, pctrnk: 0.5},
+        {x: 1, pctrnk: 0},
+      ]);
+    });
   }
 );