feat: UpdateResult returns affected rows in postgresql (typeorm#4432)

* Added 'affected' field in UpdateResult as well as in DeleteResult.
 * PostgresQueryRunner returns the number of affected rows properly
 * UpdateQueryBuilder retrieves the affected rows returned by PostgresQueryRunner and
   sets the added 'affected' field of UpdateResult properly.

Closes: typeorm#1308

src/driver/postgres/PostgresQueryRunner.ts

@@ -179,7 +179,8 @@ export class PostgresQueryRunner extends BaseQueryRunner implements QueryRunner
                     } else {
                         switch (result.command) {
                             case "DELETE":
-                                // for DELETE query additionally return number of affected rows
+                            case "UPDATE":
+                                // for UPDATE and DELETE query additionally return number of affected rows
                                 ok([result.rows, result.rowCount]);
                                 break;
                             default:

src/query-builder/UpdateQueryBuilder.ts

@@ -83,7 +83,16 @@ export class UpdateQueryBuilder<Entity> extends QueryBuilder<Entity> implements
             // execute update query
             const [sql, parameters] = this.getQueryAndParameters();
             const updateResult = new UpdateResult();
-            updateResult.raw = await queryRunner.query(sql, parameters);
+            const result = await queryRunner.query(sql, parameters);
+
+            const driver = queryRunner.connection.driver;
+            if (driver instanceof PostgresDriver) {
+                updateResult.raw = result[0];
+                updateResult.affected = result[1];
+            }
+            else {
+                updateResult.raw = result;
+            }
 
             // if we are updating entities and entity updation is enabled we must update some of entity columns (like version, update date, etc.)
             if (this.expressionMap.updateEntity === true &&

src/query-builder/result/UpdateResult.ts

@@ -10,6 +10,12 @@ export class UpdateResult {
      */
     raw: any;
 
+    /**
+     * Number of affected rows/documents
+     * Not all drivers support this
+     */
+    affected?: number;
+
     /**
      * Contains inserted entity id.
      * Has entity-like structure (not just column database name and values).
@@ -22,4 +28,4 @@ export class UpdateResult {
      */
     generatedMaps: ObjectLiteral[] = [];
 
-}
+}

test/github-issues/1308/entity/Author.ts

@@ -0,0 +1,34 @@
+import {EntitySchemaOptions} from "../../../../src/entity-schema/EntitySchemaOptions";
+import {Post} from "./Post";
+
+export class Author {
+    id: number;
+
+    name: string;
+
+    posts: Post[];
+}
+
+export const AuthorSchema: EntitySchemaOptions<Author> = {
+    name: "Author",
+
+    target: Author,
+
+    columns: {
+        id: {
+            primary: true,
+            type: Number
+        },
+
+        name: {
+            type: "varchar"
+        }
+    },
+
+    relations: {
+        posts: {
+            target: () => Post,
+            type: "one-to-many"
+        }
+    }
+};

test/github-issues/1308/entity/Post.ts

@@ -0,0 +1,35 @@
+import {EntitySchemaOptions} from "../../../../src/entity-schema/EntitySchemaOptions";
+import {Author} from "./Author";
+
+export class Post {
+    id: number;
+
+    title: string;
+
+    author: Author;
+}
+
+export const PostSchema: EntitySchemaOptions<Post> = {
+    name: "Post",
+
+    target: Post,
+
+    columns: {
+        id: {
+            primary: true,
+            type: Number
+        },
+
+        title: {
+            type: "varchar"
+        }
+    },
+
+    relations: {
+        author: {
+            target: () => Author,
+            type: "many-to-one",
+            eager: true
+        }
+    }
+};

test/github-issues/1308/issue-1308.ts

@@ -0,0 +1,49 @@
+import { closeTestingConnections, createTestingConnections, reloadTestingDatabases } from "../../utils/test-utils";
+import { Connection } from "../../../src/connection/Connection";
+import { EntitySchema } from "../../../src";
+import { Author, AuthorSchema } from "./entity/Author";
+import { Post, PostSchema } from "./entity/Post";
+
+describe("github issues > #1308 Raw Postgresql Update query result is always an empty array", () => {
+  let connections: Connection[];
+  before(
+    async () =>
+      (connections = await createTestingConnections({
+        entities: [new EntitySchema<Author>(AuthorSchema), new EntitySchema<Post>(PostSchema)],
+        dropSchema: true,
+        enabledDrivers: ["postgres"],
+      }))
+  );
+  beforeEach(() => reloadTestingDatabases(connections));
+  after(() => closeTestingConnections(connections));
+
+  async function prepareData(connection: Connection) {
+    const author = new Author();
+    author.id = 1;
+    author.name = "Jane Doe";
+    await connection.manager.save(author);
+  }
+
+  it("Update query returns the number of affected rows", () =>
+    Promise.all(
+      connections.map(async connection => {
+        await prepareData(connection);
+
+        const result1 = await connection.createQueryBuilder()
+          .update(Author)
+          .set({ name: "John Doe" })
+          .where("name = :name", { name: "Jonas Doe" })
+          .execute();
+
+        result1.affected!.should.be.eql(0);
+
+        const result2 = await connection.createQueryBuilder()
+          .update(Author)
+          .set({ name: "John Doe" })
+          .where("name = :name", { name: "Jane Doe" })
+          .execute();
+
+        result2.affected!.should.be.eql(1);
+      })
+    ));
+});