From 79365a4f4fbd230c277297b773ea4ab806b83571 Mon Sep 17 00:00:00 2001
From: Michael Toy <66150587+mtoy-googly-moogly@users.noreply.github.com>
Date: Thu, 16 Jan 2025 13:56:00 -0800
Subject: [PATCH] make schema explain shareable

---
 .../malloy-db-trino/src/trino_connection.ts   | 23 ++++++++++---------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/packages/malloy-db-trino/src/trino_connection.ts b/packages/malloy-db-trino/src/trino_connection.ts
index 3f65754a9..37dcf0e84 100644
--- a/packages/malloy-db-trino/src/trino_connection.ts
+++ b/packages/malloy-db-trino/src/trino_connection.ts
@@ -439,17 +439,10 @@ export class PrestoConnection extends TrinoPrestoConnection {
     );
   }
 
-  protected async fillStructDefForSqlBlockSchema(
-    sql: string,
-    structDef: StructDef
-  ): Promise<void> {
-    const explainResult = await this.runSQL(`EXPLAIN ${sql}`, {});
-    this.schemaFromExplain(explainResult, structDef);
-  }
-
-  protected schemaFromExplain(
+  static schemaFromExplain(
     explainResult: MalloyQueryData,
-    structDef: StructDef
+    structDef: StructDef,
+    dialect: Dialect
   ) {
     if (explainResult.rows.length === 0) {
       throw new Error(
@@ -474,10 +467,18 @@ export class PrestoConnection extends TrinoPrestoConnection {
       );
     }
 
-    const schemaDesc = new TrinoPrestoSchemaParser(lines[0], this.dialect);
+    const schemaDesc = new TrinoPrestoSchemaParser(lines[0], dialect);
     structDef.fields = schemaDesc.parseQueryPlan();
   }
 
+  protected async fillStructDefForSqlBlockSchema(
+    sql: string,
+    structDef: StructDef
+  ): Promise<void> {
+    const explainResult = await this.runSQL(`EXPLAIN ${sql}`, {});
+    PrestoConnection.schemaFromExplain(explainResult, structDef, this.dialect);
+  }
+
   unpackArray(data: unknown): unknown[] {
     return JSON.parse(data as string);
   }