Column Properties with the PurePerl MySQL API

Using the PurePerl MySQL API – Part 6

Writing a Perl Module

Foreword: In this part of the series, I talk about table column properties obtained with the PurePerl MySQL API.

By: Chrysanthus Date Published: 28 Jan 2015

Introduction

This is part 6 of my series, Using the PurePerl MySQL API. In this part of the series, I talk about table column properties obtained with the PurePerl MySQL API. PurePerl stands for Pure Perl. It is Perl Software without C software underneath. You should have read the previous parts of the series before reaching here, as this is a continuation.

The Mysql package has the array variable, @Fields. It should have all the column properties:

Structure of the @Fields Array
@Fields is a two dimensional array, where the number of rows is the number of columns (fields) in the result set. Each row has the following values in the order given:

- Name of column: this is the alias name. It would be the original name if there was no alias name;
- Name of database for the result set;
- Name of table having the column: this is the alias name. It would be the original name if there was no alias name;
- Character Set Code;
- Column (Field) length;
- Type Code;
- Field Type;
- Decimal point precision of field values;
- Default column value, if present

As you can see, there are 9 properties.

Displaying a row of the Array
The following code returns a result set and the properties of the second column are displayed:

        my $sel = "SELECT * FROM pet";
        if (Mysql::query($sel) != 1)
            {
                print $Mysql::Error_msg, "\n";
            }
        else
            {
                for (my $j=0; $j<9; ++$j)
                    {
                           print $Mysql::Fields[1][$j],  ', ';
                    }
            }

In the code, [1] is for the second column; for the third column you would type, [2]; for fourth, [3] and so on. 9 in the first line of the for-loop is for the 9 properties.

Field Type
The word, field in this article means column or column title. To obtain the field type for the first column, you can use the following code:

        my $sel = "SELECT * FROM pet";
        if (Mysql::query($sel) != 1)
           {
                print $Mysql::Error_msg, "\n";
            }
        else
            {
                  print $Mysql::Fields[0][6], "\n";
            }

That is it for this part of the series. We stop here and continue in the next part.

Chrys

Broad Network

Related Articles

Column Properties with the PurePerl MySQL API

Using the PurePerl MySQL API – Part 6

Writing a Perl Module

Introduction

Comments