Leiden Booktrade database

Sample queries


Visualisations

Bar Chart

To produce a bar chart, the SELECT list of the SQL query needs to contain two values. The first value needs to specify the labels to be used for the various bars. The second value needs to be a number. This number determines the size of the bar.

Sample query




Line Chart

Line charts can be generated from the table TOTAL. This table contains aggregate counts about the number of people active in the various professions in Leiden booktrade in the early modern period. To create a line chart, write an SQL query with a select list containing two columns. The values of the first column will be shown on the X-axis and the values of the second column on the Y-axis.

Sample query




Map

To produce a bar chart, the SELECT list of the SQL query needs to mention the latitude and the longitude of the locations to be plotted on the map.

Sample query

SELECT latitude, longitude FROM EMPLOYMENT LEFT JOIN PROFESSION ON function = PR_ID LEFT JOIN PERSON ON person = P_ID LEFT JOIN ADDRESS ON ADDRESS.person = P_ID WHERE PROFESSION.name = 'boekverkoper'