Data Science – Database Table

Database Table

A database table is a table with structured data.

The following table shows a database table with health data extracted from a sports watch:

DurationAverage_PulseMax_PulseCalorie_BurnageHours_WorkHours_Sleep
3080120240107
3085120250107
459013026087
459513027087
4510014028007
6010514029078
6011014530078
6011514531088
7512015032008
7512515033088

This dataset contains information of a typical training session such as duration, average pulse, calorie burnage etc.

Database Table Structure

A database table consists of column(s) and row(s):

Column 1Column 2Column 3Column 4Column 5Column 6
DurationAverage_PulseMax_PulseCalorie_BurnageHours_WorkHours_Sleep
Row 13080120240107
Row 23085120250107
Row 3459013026087
Row 4459513027087
Row 54510014028007
Row 66010514029078
Row 76011014530078
Row 86011514531088
Row 97512015032008
Row 107512515033088

A row is a horizontal representation of data.

A column is a vertical representation of data.

Variables

A variable is defined as something that can be measured or counted.

Examples can be characters, numbers or time.

In the example under, we can observe that each column represents a variable.

DurationAverage_PulseMax_PulseCalorie_BurnageHours_WorkHours_Sleep
3080120240107
3085120250107
459013026087
459513027087
4510014028007
6010514029078
6011014530078
6011514531088
7512015032008
7512515033088

There are 6 columns, meaning that there are 6 variables (Duration, Average_Pulse, Max_Pulse, Calorie_Burnage, Hours_Work, Hours_Sleep).

There are 11 rows, meaning that each variable has 10 observations.

But if there are 11 rows, how come there are only 10 observations?

It is because the first row is the label, meaning that it is the name of the variable.