Joined filtered Sources (#1883)

* Joined filtered Sources * It turns out the postgres and snowflake really didn't support this. the joined nested table was inaccessible. Stubbing for now.
malloydata · Sep 7, 2024 · 89920bc · 89920bc
1 parent 5196b21
commit 89920bc
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Showing 4 changed files with 49 additions and 6 deletions.
diff --git a/packages/malloy/src/dialect/postgres/postgres.ts b/packages/malloy/src/dialect/postgres/postgres.ts
@@ -103,6 +103,7 @@ export class PostgresDialect extends PostgresBase {
   supportsNesting = true;
   experimental = false;
   readsNestedData = false;
+  supportsComplexFilteredSources = false;
 
   quoteTablePath(tablePath: string): string {
     return tablePath

diff --git a/packages/malloy/src/dialect/snowflake/snowflake.ts b/packages/malloy/src/dialect/snowflake/snowflake.ts
@@ -110,6 +110,7 @@ export class SnowflakeDialect extends Dialect {
   dontUnionIndex = false;
   supportsQualify = false;
   supportsPipelinesInViews = false;
+  supportsComplexFilteredSources = false;
 
   // don't mess with the table pathing.
   quoteTablePath(tablePath: string): string {

diff --git a/packages/malloy/src/model/malloy_query.ts b/packages/malloy/src/model/malloy_query.ts
@@ -2775,17 +2775,31 @@ class QueryQuery extends QueryField {
           qf.generateExpression(this.rootResult)
         );
       }
-      if (ji.children.length === 0 || conditions === undefined) {
+
+      if (
+        ji.children.length === 0 ||
+        conditions === undefined ||
+        !this.parent.dialect.supportsComplexFilteredSources
+      ) {
+        // LTNOTE: need a check here to see the children's where: conditions are local
+        //  to the source and not to any of it's joined children.
+        //  In Presto, we're going to get a SQL error if in this case
+        //  for now.  We need to inspect the 'condition' of each of the children
+        //  to see if they reference subchildren and blow up if they do
+        //  or move them to the where clause with a (x.distnct_key is NULL or (condition))
+        //
+        // const childrenFiltersAreComplex = somethign(conditions)
+        // if (conditions && childrenFiltersAreComplex !this.parent.dialect.supportsComplexFilteredSources) {
+        //   throw new Error(
+        //     'Cannot join a source with a complex filter on a joined source'
+        //   );
+        // }
+
         if (conditions !== undefined && conditions.length >= 1) {
           filters = ` AND (${conditions.join(' AND ')})`;
         }
         s += ` ${matrixOperation} JOIN ${structSQL} AS ${ji.alias}\n  ON ${onCondition}${filters}\n`;
       } else {
-        if (!this.parent.dialect.supportsComplexFilteredSources) {
-          throw new Error(
-            'Cannot join a source with a filter on a joined source'
-          );
-        }
         let select = `SELECT ${ji.alias}.*`;
         let joins = '';
         for (const childJoin of ji.children) {

diff --git a/test/src/databases/all/expr.spec.ts b/test/src/databases/all/expr.spec.ts
@@ -676,6 +676,33 @@ describe.each(runtimes.runtimeList)('%s', (databaseName, runtime) => {
     `).malloyResultMatches(runtime, {model_count: 60461, b_count: 355});
     }
   );
+
+  test('joined filtered explores with NO dependencies', async () => {
+    await expect(`
+      source: sf is ${databaseName}.table('malloytest.state_facts') extend {
+        measure: state_count is count()
+        primary_key: state
+      }
+
+      source: al is sf extend {where: state = 'AL'}
+
+      source: a is sf extend {
+        where: state ~ 'A%'
+        join_one: al with state
+      }
+
+      source: allx is sf extend {
+        join_one: a with state
+      }
+      // # test.debug
+      run: allx -> {
+        aggregate:
+          allx is state_count
+          a is a.state_count
+          al is a.al.state_count
+      }
+    `).malloyResultMatches(runtime, {allx: 51, a: 4, al: 1});
+  });
 });
 
 describe.each(runtimes.runtimeList)('%s', (databaseName, runtime) => {