This PR serves both as an issue report and a preliminary attempt to fix a problem in the ScanStruct method of goqu. The method encounters errors when dealing with structs that contain interface types, specifically those implementing the sql.Scanner interface.
The ScanStruct method fails with errors like the following when it encounters an interface type within a struct:
sql: Scan error on column index 1, name "value": unsupported Scan, storing driver.Value type string into type *sql.Scanner
This issue arises because the newColumnMap function assigns the interface type to GoType rather than the concrete type of the object in use.
I've made an attempt to resolve this by detecting if a struct field's type is Interface and then replacing f.Type with concreteType. This approach seems to work, but it introduces a potential issue where the scanner might reuse the same type for subsequent scans, when the interface could be implemented by different objects (the second testcase with NullInt32 object).
Well, the question is, if I am not overthinking it :)
This PR serves both as an issue report and a preliminary attempt to fix a problem in the
ScanStructmethod ofgoqu. The method encounters errors when dealing with structs that contain interface types, specifically those implementing thesql.Scannerinterface.The
ScanStructmethod fails with errors like the following when it encounters an interface type within a struct:This issue arises because the
newColumnMapfunction assigns the interface type toGoTyperather than the concrete type of the object in use. I've made an attempt to resolve this by detecting if a struct field's type isInterfaceand then replacingf.TypewithconcreteType. This approach seems to work, but it introduces a potential issue where the scanner might reuse the same type for subsequent scans, when the interface could be implemented by different objects (the second testcase withNullInt32object).Well, the question is, if I am not overthinking it :)
So, what do you think?