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Introduction

    DATABASE - INTRODUCTION

    Datas like any apllicación of this type are organized in tables or files and fields or columns. Tables are defined by a descriptor (a name without special characters). Each field of the table will have a single and unique descriptor within the table. Besides the descriptor, the field is defined by the type and length. Types can be:
    A. alphanumeric
    B. Alphanumeric Digits. (It behaves as alpha but only supports numeric digits).
    D. Dates. Only supports lengths 6/8.
    L. Logical. It only supports lengths of 1.
    N. numeric integer
    1-9. Numeric with n decimal places.
    T. Time.
    Later we will access this data using a very simple syntax of type FIELD{TABLE}, either for consultation or modification. For example if we have a table called ITEMS and across fields of this table, we have one called PRICE, we can access this data using the expression PRICE{ITEMS}. Of course as with any table, we will get the correct position previously in the row you wish to access. This is automatic in maintenance utilities and movements, but it can be done in a specific way, for example when we write scrpts wifth FILEFIND and FILELOCATE functions.
    Depending on how we access to data rows, there are three types of files, relatives, indexed or SQL databases. This selection is taken at compile time, so that an application can only use one of these types.