feat: add set datatype support for MySQL/MariaDB (typeorm#4538)

Set possible values defined using existing enum column option.
Sets are implemented as arrays.

Closes: typeorm#2779

docs/entities.md

@@ -294,7 +294,7 @@ or
 `bit`, `int`, `integer`, `tinyint`, `smallint`, `mediumint`, `bigint`, `float`, `double`,
 `double precision`, `dec`, `decimal`, `numeric`, `fixed`, `bool`, `boolean`, `date`, `datetime`,
 `timestamp`, `time`, `year`, `char`, `nchar`, `national char`, `varchar`, `nvarchar`, `national varchar`,
-`text`, `tinytext`, `mediumtext`, `blob`, `longtext`, `tinyblob`, `mediumblob`, `longblob`, `enum`,
+`text`, `tinytext`, `mediumtext`, `blob`, `longtext`, `tinyblob`, `mediumblob`, `longblob`, `enum`, `set`,
 `json`, `binary`, `varbinary`, `geometry`, `point`, `linestring`, `polygon`, `multipoint`, `multilinestring`,
 `multipolygon`, `geometrycollection`
 
@@ -390,6 +390,52 @@ export class User {
 }
 ```
 
+### `set` column type
+
+`set` column type is supported by `mariadb` and `mysql`. There are various possible column definitions:
+
+Using typescript enums:
+```typescript
+export enum UserRole {
+    ADMIN = "admin",
+    EDITOR = "editor",
+    GHOST = "ghost"
+}
+
+@Entity()
+export class User {
+
+    @PrimaryGeneratedColumn()
+    id: number;
+
+    @Column({
+        type: "set",
+        enum: UserRole,
+        default: [UserRole.GHOST, UserRole.EDITOR]
+    })
+    roles: UserRole[]
+
+}
+```
+
+Using array with `set` values:
+```typescript
+export type UserRoleType = "admin" | "editor" | "ghost",
+
+@Entity()
+export class User {
+
+    @PrimaryGeneratedColumn()
+    id: number;
+
+    @Column({
+        type: "set",
+        enum: ["admin", "editor", "ghost"],
+        default: ["ghost", "editor"]
+    })
+    roles: UserRoleType[]
+}
+```
 
 ### `simple-array` column type
 

src/decorator/columns/Column.ts

@@ -70,6 +70,12 @@ export function Column(type: "enum", options?: ColumnCommonOptions & ColumnEnumO
  */
 export function Column(type: "simple-enum", options?: ColumnCommonOptions & ColumnEnumOptions): Function;
 
+/**
+ * Column decorator is used to mark a specific class property as a table column.
+ * Only properties decorated with this decorator will be persisted to the database when entity be saved.
+ */
+export function Column(type: "set", options?: ColumnCommonOptions & ColumnEnumOptions): Function;
+
 /**
  * Column decorator is used to mark a specific class property as a table column.
  * Only properties decorated with this decorator will be persisted to the database when entity be saved.

src/driver/mysql/MysqlDriver.ts

@@ -120,6 +120,7 @@ export class MysqlDriver implements Driver {
         "longblob",
         "longtext",
         "enum",
+        "set",
         "binary",
         "varbinary",
         // json data type
@@ -459,6 +460,9 @@ export class MysqlDriver implements Driver {
 
         } else if (columnMetadata.type === "enum" || columnMetadata.type === "simple-enum") {
             return "" + value;
+
+        } else if (columnMetadata.type === "set") {
+            return DateUtils.simpleArrayToString(value);
         }
 
         return value;
@@ -498,6 +502,8 @@ export class MysqlDriver implements Driver {
             && columnMetadata.enum.indexOf(parseInt(value)) >= 0) {
             // convert to number if that exists in possible enum options
             value = parseInt(value);
+        } else if (columnMetadata.type === "set") {
+            value = DateUtils.stringToSimpleArray(value);
         }
 
         if (columnMetadata.transformer)
@@ -564,6 +570,10 @@ export class MysqlDriver implements Driver {
             return `'${defaultValue}'`;
         }
 
+        if ((columnMetadata.type === "set") && defaultValue !== undefined) {
+            return `'${DateUtils.simpleArrayToString(defaultValue)}'`;
+        }
+
         if (typeof defaultValue === "number") {
             return "" + defaultValue;
 

src/driver/mysql/MysqlQueryRunner.ts

@@ -1333,7 +1333,7 @@ export class MysqlQueryRunner extends BaseQueryRunner implements QueryRunner {
                             tableColumn.scale = parseInt(dbColumn["NUMERIC_SCALE"]);
                     }
 
-                    if (tableColumn.type === "enum" || tableColumn.type === "simple-enum") {
+                    if (tableColumn.type === "enum" || tableColumn.type === "simple-enum" || tableColumn.type === "set") {
                         const colType = dbColumn["COLUMN_TYPE"];
                         const items = colType.substring(colType.indexOf("(") + 1, colType.indexOf(")")).split(",");
                         tableColumn.enum = (items as string[]).map(item => {

src/driver/types/ColumnTypes.ts

@@ -161,6 +161,7 @@ export type SimpleColumnType =
 
     // other types
     |"enum" // mysql, postgres
+    |"set" // mysql
     |"cidr" // postgres
     |"inet" // postgres, cockroachdb
     |"macaddr"// postgres

test/github-issues/2779/entity/Post.ts

@@ -0,0 +1,15 @@
+import { Column, Entity, PrimaryGeneratedColumn } from "../../../../src";
+import { Role } from "../set";
+
+@Entity("post")
+export class Post {
+
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  @Column("set", {
+    default: [Role.Admin, Role.Developer],
+    enum: Role 
+  })
+  roles: Role[];
+}

test/github-issues/2779/issue-2779.ts

@@ -0,0 +1,44 @@
+import "reflect-metadata";
+import { Connection } from "../../../src/connection/Connection";
+import { closeTestingConnections, createTestingConnections } from "../../utils/test-utils";
+import { Post } from "./entity/Post";
+import { expect } from "chai";
+import { Role } from "./set";
+
+describe("github issues > #2779 Could we add support for the MySQL/MariaDB SET data type?", () => {
+
+  let connections: Connection[];
+  before(async () => {
+    connections = await createTestingConnections({
+      entities: [__dirname + "/entity/*{.js,.ts}"],
+      enabledDrivers: ["mariadb", "mysql"],
+      schemaCreate: true,
+      dropSchema: true,
+    });
+  });
+  after(() => closeTestingConnections(connections));
+
+  it("should create column with SET datatype", () => Promise.all(connections.map(async connection => {
+
+    const queryRunner = connection.createQueryRunner();
+    const table = await queryRunner.getTable("post");
+    table!.findColumnByName("roles")!.type.should.be.equal("set");
+    await queryRunner.release();
+
+  })));
+
+  it("should persist and hydrate sets", () => Promise.all(connections.map(async connection => {
+
+    const targetValue = [Role.Support, Role.Developer];
+
+    const post = new Post();
+    post.roles = targetValue;
+    await connection.manager.save(post);
+    post.roles.should.be.deep.equal(targetValue);
+
+    const loadedPost = await connection.manager.findOne(Post);
+    expect(loadedPost).not.to.be.undefined;
+    loadedPost!.roles.should.be.deep.equal(targetValue);
+  })));
+
+});

test/github-issues/2779/set.ts

@@ -0,0 +1,5 @@
+export enum Role {
+  Admin = "Admin",
+  Support = "Support",
+  Developer = "Developer"
+}