DefinedColumnType specifies the type of predefined columns.
Enumeration value list
DCT_INTEGER: integer
DCT_DOUBLE: floating-point number
DCT_BOOLEAN: Boolean
DCT_STRING: string
DCT_BLOB: binary
enum DefinedColumnType {
DCT_INTEGER = 1;
DCT_DOUBLE = 2;
DCT_BOOLEAN = 3;
DCT_STRING = 4;
DCT_BLOB = 7;
}