fix: correct JOIN order for nested includes with junction tables (#29)

Author: mithleshjs

src/lib/build.ts

@@ -48,17 +48,18 @@ export function buildSelectQuery<T = unknown, R extends string = "none">(
 
 	// Handle include
 	if (query.include) {
-		for (const [relation, relationQuery] of Object.entries(query.include)) {
-			if (!relations[relation]) {
-				throw new Error(`Relation ${relation} is not defined`);
+		for (const [relationName, relationQuery] of Object.entries(query.include)) {
+			const relation = relations[relationName];
+			if (!relation) {
+				throw new Error(`Relation ${relationName} is not defined`);
 			}
 			const innerQuery = buildSelectQuery(
-				relation,
+				relationName,
 				relationQuery,
 				relations,
 				true,
 			);
-			args.join += join("LEFT LATERAL", relations[relation], innerQuery);
+			args.join += join("LEFT LATERAL", relation, innerQuery);
 		}
 	}
 
@@ -214,12 +215,12 @@ export function sql(
 	},
 ): string {
 	let sql = `${params?.select || params?.delete || params?.update || ""}`;
-	if (params.join) {
-		sql += `${params.join}`;
-	}
 	if (append?.join) {
 		sql += `${append?.join}`;
 	}
+	if (params.join) {
+		sql += `${params.join}`;
+	}
 	if (params.where && Object.keys(params.where).length > 0) {
 		sql += ` WHERE ${where(params.where, "AND", params.relations || {})}`;
 	}

src/test/build.test.ts

@@ -37,7 +37,7 @@ describe("sql", () => {
 		};
 		const result = sql(params, append);
 		expect(result).toBe(
-			"SELECT * FROM table JOIN other_table ON table.id = other_table.table_id JOIN another_table ON table.id = another_table.table_id",
+			"SELECT * FROM table JOIN another_table ON table.id = another_table.table_id JOIN other_table ON table.id = other_table.table_id",
 		);
 	});
 
@@ -101,7 +101,7 @@ describe("sql", () => {
 		};
 		const result = sql(params, append);
 		expect(result).toBe(
-			`SELECT * FROM table JOIN other_table ON table.id = other_table.table_id JOIN another_table ON table.id = another_table.table_id WHERE "id" = 1 AND other_table.name = "test" GROUP BY "name" HAVING COUNT("name") = 1 ORDER BY "name" ASC LIMIT 10 OFFSET 5 RETURNING "id", "name"`,
+			`SELECT * FROM table JOIN another_table ON table.id = another_table.table_id JOIN other_table ON table.id = other_table.table_id WHERE "id" = 1 AND other_table.name = "test" GROUP BY "name" HAVING COUNT("name") = 1 ORDER BY "name" ASC LIMIT 10 OFFSET 5 RETURNING "id", "name"`,
 		);
 	});
 });