toJson method
Implementation
Map<String, Object?> toJson() => {
if (type != null) 'type': type!.toJson(),
if (sqlType != null) 'sqlType': sqlType,
if (defaultValue != null) 'default': defaultValue!.toJson(),
if (collation != null) 'collation': collation,
if (charset != null) 'charset': charset,
};