}
			}

			if !isSameType {
				alterColumn = true
			}
		}
	}

	if !isSameType {
		// check size
		if length, ok := columnType.Length(); length != int64(field.Size) {
			if length > 0 && field.Size > 0 {
				alterColumn = true
			} else {
				// has size in data type and not equal
				// Since the following code is frequently called in the for loop, reg optimization is needed here