The sample below shows the number of feature classes of each type that are stored in the system table TB_DICTIONARY.
select F_CLASS_TYPE,
count(F_CLASS_TYPE) from TB_DICTIONARY group by F_CLASS_TYPE
In a Line chart, each line corresponds to a series, and the select statement could return the following <series>,<X>,<Y>.
1,15,20
1,16,30
1,17,31
...
2,15,20
2,16,30
2,18,19
...
3,15,20
3,16,30
3,17,31
...
In the chart, 3 lines would be drawn.