Wrong migration created because of default column value format

[ValiDraganescu]

Issue type:

[ ] question
[x] bug report
[ ] feature request
[ ] documentation issue

Database system/driver:

[ ] cordova
[ ] mongodb
[ ] mssql
[x] mysql / mariadb
[ ] oracle
[ ] postgres
[ ] cockroachdb
[ ] sqlite
[ ] sqljs
[ ] react-native
[ ] expo

TypeORM version:

[ ] latest
[ ] @next
[x] 0.2.22 (or put your version here)

Steps to reproduce or a small repository showing the problem:

I have the following entity

@Entity({
  name: "poi"
})
export class Poi {

  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  normalizedNameEn: string;

  @Column({
    type: "decimal",
    precision: 11,
    scale: 8,
    default: 0
  })
  lat: number;

  @Column({
    type: "decimal",
    precision: 11,
    scale: 8,
    default: 0
  })
  lon: number;

  @Column()
  isActivated: Boolean;
}

lat and lon ware wrongly defined as int previously so I updated to decimal

when I run migrate:generate I it creates a migration file that (amongst others) contains the following lines

await queryRunner.query("ALTER TABLE `poi` CHANGE `lat` `lat` decimal(11,8) NOT NULL DEFAULT 0", undefined);
await queryRunner.query("ALTER TABLE `poi` CHANGE `lon` `lon` decimal(11,8) NOT NULL DEFAULT 0", undefined);

after I run the migration and later generate a new one I always get the following

public async up(queryRunner: QueryRunner): Promise<any> {
        await queryRunner.query("ALTER TABLE `poi` CHANGE `lat` `lat` decimal(11,8) NOT NULL DEFAULT 0", undefined);
        await queryRunner.query("ALTER TABLE `poi` CHANGE `lon` `lon` decimal(11,8) NOT NULL DEFAULT 0", undefined);
    }

public async down(queryRunner: QueryRunner): Promise<any> {
        await queryRunner.query("ALTER TABLE `poi` CHANGE `lon` `lon` decimal(11,8) NOT NULL DEFAULT '0.00000000'", undefined);
        await queryRunner.query("ALTER TABLE `poi` CHANGE `lat` `lat` decimal(11,8) NOT NULL DEFAULT '0.00000000'", undefined);
    }

However, I did some tests and I found that if I define lat and lon with default '0.00000000' typeorm will report no changes (as it should)