Using the Queries in Map 3D

Queries are very productive tools inside Map 3D. We can use these to Reference or Create Data from one file to another. This will allow us pull info needed for a current project from other sources. With this tool we can extract data in many different ways. In fact, we can extract anything from specific object data to which layer the information resides on, or both. The software also allows us to pull it in as a preview or draw the data directly into our new drawing. So as we can all see, this can be helpful in many different types of situations. In this article we will look at pulling in data based on location and property value simultaneously. This it what is known as a compound query and will let us get pretty specific about what we want to see in our drawing.

In this process the first thing to do is to get the drawings we will be pulling data from and attach those to our current drawing as source drawings. These must be attached in order to create a path the computer can use. We can do this by clicking Data in the map explorer and choosing to attach the source drawing. At this point we can browse through our aliases (designated directories) and find the one that contains the drawings we are searching for.

At this point we simply choose the drawings within the folder we want to reference and choose add.

Once the drawings are added in the map explorer we are free to retrieve data from those sources.

From the screenshot above you should be able to see that we have four different types of queries to choose from. Location type allows us to choose a physical location to pull data from on the map. Property lets us pull objects by an AutoCAD property such as layer or linetype. Data query type has us pulling info by Attributes or Object Data, etc. Finally the SQL type requires us to pull from an external database, like a Microsoft Database file (.mdb) for example. As I wrote before, in our query we want to retrieve the land value in a specified location on the map. The first thing we are going to do is execute a preview query of all the parcels to see where they are located.

In order to get the parcels in, we need to choose property as our query type. This will let us select which AutoCAD property we want and give us access to the AutoCAD layers in all of the attached drawings. Here we can choose to get our parcels layer in which all the parcels reside.

Once we OK the parcels layer, we are taken back to the query definition dialogue box where we can execute the query in preview mode to see our parcels without actually creating objects in our drawing.

Now we can see the parcels, but when executing the query in preview mode it acts a lot like an xref. Now we will be able to clear our current query and begin a new one that will give us what we want.

When we begin our new query we will simply clear the previewed one and select location as our new query type. Then it will ask us how we want to define the location. We will have many options on how to do that in the dialogue box you see below.

In this case we are going to choose a polygon to enclose the north side of town.

Once we have the location specified we will make sure that the And modifier is chosen in the query type box. We will now choose the data we wish to retrieve by clicking Data.

When we click the Data option we will go to the Parcels table and choose to get Land_Value section of the object data. We can choose a modifier of equal to, less than, greater than and so on. We will choose greater than in the amount of 1,000,000.

As you can see, our query is now more defined and will give us exactly what we are looking for. We can define our query as specifically as we want, and the and modifier will allow us to add as many parameters as we need.

Once we execute the query we just designed in draw mode, we will get every parcel in the specific location we designated in excess of $1,000,000 in value, as you can see in the picture below.

In Map 3D 2008 Queries can help us pull very specific data from drawings very quickly, as opposed to sorting through them basically by hand. This allows us to make display maps pertaining to specific areas quickly and allows us to export this data also if need be. It can be a big time saver and is pretty neat to see exactly how specific you can get with it.
 

This page last edited on Thursday, June 03, 2010