Nullable enum columns are not recognized as nullable by generated code

[jackdelab]

Version

1.10.0

What happened?

Generated code causes an error when it tried to scan a row from a table with a nullable enum column.

Relevant generated code:

type Resource struct {
	ID             int32            `json:"id"`
	KeyState       ResourceKeyState `json:"key_state"`
}

type ResourceKeyState string

const (
	ResourceKeyStateNOTYETACTIVE      ResourceKeyState = "NOT_YET_ACTIVE"
	ResourceKeyStateACTIVE            ResourceKeyState = "ACTIVE"
	ResourceKeyStateINACTIVE          ResourceKeyState = "INACTIVE"
	ResourceKeyStateDELETIONSCHEDULED ResourceKeyState = "DELETION_SCHEDULED"
)

func (e *ResourceKeyState) Scan(src interface{}) error {
	switch s := src.(type) {
	case []byte:
		*e = ResourceKeyState(s)
	case string:
		*e = ResourceKeyState(s)
	default:
		return fmt.Errorf("unsupported scan type for ResourceKeyState: %T", src)
	}
	return nil
}

Expected:
Generated code should recognize that the column can have null values, and scan values from it accordingly.

Relevant log output

{"log.level":"ERROR","@timestamp":"2022-06-01T03:58:17.096Z","log.origin":{"file.name":"<REDACTED>.go","file.line":179},"message":"sql: Scan error on column index 7, name \"key_state\": unsupported scan type for ResourceKeyState: <nil> (rest of log message REDACTED)"}

Database schema

CREATE TABLE `resource` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `key_state` enum('NOT_YET_ACTIVE','ACTIVE','INACTIVE','DELETION_SCHEDULED') DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

SQL queries

/* name: GetResourceById :one */
SELECT * FROM resource
WHERE id = ? ;

Configuration

{
  "version": "2",
  "sql": [
    {
      "schema": "sqlc/<REDACTED>.sql",
      "queries": "sqlc/<REDACTED>.sqlc.sql",
      "engine": "mysql",
      "gen": {
        "go": {
          "emit_json_tags": true,
          "package": "sqlcgen",
          "out": "components/sqlc"
        }
      }
    }
  ]
}

Playground URL

No response

What operating system are you using?

Linux, macOS

What database engines are you using?

MySQL

What type of code are you generating?

Go

[kyleconroy]

Fixed by #1485