This is a basic program that creates a simple database. However, as this task must be done usually once, it can be done by the DBL command-line interface.
include "dbl.h"
int main
include
int main
Library structure
Class database
This class stores the database name and its tables. The main functions are: char *name; //get the database name char *name; //set the database name void new_tab; //create a new table table *get_tab; //return the pointer to the table
Useful functions that use the class database are: void write; //write the database structure into a file friend void read; //read the database structure from a file friend void del; //delete the database and its tables files friend void print; //print the database on the screen
Class table
This class stores the table name and its structure, the columns of the table. The main functions are: char *name; //get the table name char *name; //set the table name void add_col; //add a new column to the table void add_col; column *get_col; //get the column by its index column *get_col; //get the column by its name int num_col; //get the number of columns in the table //finish the structure of the table. //This function must be called after adding all columns or after reading the structure of the table from a file void set_structure; row new_row; //get a new row with the table structure
Useful functions that use the class table are: void write; //write the table structure into a file void read; //read the table structure from a file friend void del; //delete the table files, header and data files void print; //print the table on the screen friend std::ostream &operator<<; //print the table structure int num_row; //get the number of rows in the data file of the table
Class row
This class stores the columns of the table and the data to be stored in the data file. The main functions are: void set; //set the storage of a column by its index void set; //set the value to be stored in a column by its index storage *get; //get the storage from the a column by its index
Useful functions that use the class row are: void write; //write the data in the data file of the table void read; //read the data from the data file of the table void del; //delete the data from the data file of the table
Class storage
This class stores the column and a value for that column. The main functions are: char *value; //get the value being stored by the object void value; //set the value to be stored void value; //set the value to be stored, a C-style string and all functions of the class column.
Useful functions that use the class storage are: int get_int; //get the integer being stored char get_char; //get the char being stored bool get_bool; //get the bool being stored float get_float; //get the float being stored double get_double; //get the double being stored
Class column
This class stores the name and the structure of a column. The main functions are: char *name; //get the name of the column char *name; //set the name of the column char type; //get the type of the column char type; //set the type of the column int length; //get the length of the array that the column can hold int length; //set the length of the array that the column can hold, len>0 void pkey; //set if the column is the primary key or not char pkey; //get if the column is the primary key or not int total_size; //get the total size, in bytes, that the column can hold
Class index
This class stores the indexes of a table. The main functions are: int seek; //look for a value in the indexes int seek; //look for a C-style string in the indexes
Useful functions that use the class index are: void write; //write the indexes of a table into a file void read; //read the indexes from a file
DBL command-line interface
By the DBL command-line interface program one can create a database, a table, and add columns to this table, besides other operations such as printing.
