Transformers and FindOperators like MoreThan or Raw

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 [ ] 0.x.x (or put your version here)

Steps to reproduce or a small repository showing the problem: when use transformer like this

@Column({
        name: "date_time",
        type: "datetime",
        transformer: {
            from: (date: Date) =>moment(date).format("YYYY-MM-DD HH:mm:ss"),
            to: (date: string) => moment(date).toDate(),
        }
    })
    dateTime: string;

find operators like MoreThan and Raw doesn’t work properly for date fields.

// success
let data = await getRepository(BdBill).find({
    dateTime:"2019-04-10 06:47:18"
});

//  all failure under
let data = await getRepository(BdBill).find({
    dateTime:LessThan("2019-04-10 06:47:18")
});
let data = await getRepository(BdBill).find({
    dateTime:LessThan(new Date())
});
let data = await getRepository(BdBill).find({
    dateTime: Raw(alias =>`${alias} > ${new Date()}`)
});
let data = await getRepository(BdBill).find({
    dateTime: Raw(alias =>`${alias} > str_to_date('2019-04-10 06:47:18','%Y-%m-%d %H:%i:%s')`)
});

[sgronblo]

So what is the recommended workaround if you want to use value transformers and FindOperators? I didn’t really understand the reasoning why this problem cannot be solved in Typeorm?

[kaedwen]

There is a hacky way to manipulate the value inside the FindOperator

      transformer: {
        from: (value: any) => {
          if (!NullOrUndefined(value) && Number(value)) {
            return new Date(Number(value));
          }
        },
        to: (value: any) => {
          if (value) {
            if (value instanceof Date) {
              return value.getTime();
            } else if (value instanceof FindOperator) {
              
              if (value.value instanceof Date) {
                (value as any)._value = value.value.getTime();
              }

              return value;
              
            }
          }
        }
      }

This seems to work with all FindOperators. Better solution would be to flag value inside FindOperator to NOT readonly …