A query is a mathematical question that you pose to your database to collect information. In MapInfo Pro, the following four query builders are available, SQL Select, Simple Select, Select By Location and the SQL window. You can access these from the SQL list in the Selection group under the TABLE, MAP and SPATIAL tabs.
In the case of Select, you can pose a question of a single table. For example,
- Which of my customers spent more than $20,000?
- Which of my customers live in Vermont?
With Select By Location, you can select objects from one table based on their location relative to objects in another table.
In the case of SQL Select and the SQL window, you can ask your question from one or several table(s) of information and perform these tasks:
- Derive new columns - columns that calculate new values based on the contents of your existing columns.
- Aggregate your data so that you see only a listing of subtotals instead of seeing your entire table.
- Combine two or more tables into one results table.
- Show only the columns and rows that interest you.