Pee Dee GIS Users Group

SQL is the language we use to do our every day queries. SQL stands for Structured Query Language and there is an enormous amount of help to be found on the internet for this language. For most of us we use the SQL with a simple statement such as [fieldname] = “somevalue” and this is sufficient to get the job done, but SQL will do so much more.

When beginning in SQL [fieldname] = “somevalue” is an effective way to search for and find the features we are after. There are other statements that can be more generic such as [fieldname] Like “the beginningofsomevalue%” or [fieldname] Like “%theendofsomevalue” that will return the attributes that begin with some value and the % sign is a wildcard character that represents any number of characters that follow. For example if your SQL statement was [fieldname] Like “B%” then any value in the field that began with letter “B” would be selected. The % sign at the end of the some value statement requests for all characters that follow, but % sign at the beginning of the some value statement requests all characters that precede the value.

I think that most of the useful operators are on our standard “Select by Attributes” dialog box. There are some however that are not on the dialog box that are still available for use. Such as [fieldname]  IN( ‘somevalue’, ‘someothervalue’) or [fieldname]  BETWEEN somevalue AND someothervalue.

Here is a much more complicated query which finds duplicate records [fieldname] In (SELECT [fieldname] FROM [tablename] As Tmp GROUP BY [fieldname] HAVING Count(*)>1 )

So this is your mission, should you choose to accept it. In the comments area below demonstrate and explain a statement not already used. If the statement is complex submit a post where we all may learn.

Many of us have our little secrets (or not so secret) ways of labeling. ESRI does a great job of documenting how to label our features. Labeling is a very important part of our cartography that we need to pay close attention too. Strengths and weaknesses in our labeling can help or hurt a good map.

With that being said I thought I might share a few of mine:

My first tip is when you are labeling for background information soften the labels. An example would be if you are labeling streets to help people with their location. I try to make these labels as weak as I can, and keep the labels legible. For a light colored background use a soft grey (a dark color) for a dark background use a soft yellow (a light color). The idea is to have information there without taking away from what you are actually showing.

My next tip is just opposite of the first make those labels easy to read. Make them standout by using high contrast colors, text backgrounds, and halos. For those of you who do not know how to get to these properties follow the instructions below:

• Right click on your feature class in the table of contents
• Select “Properties”
• In the “Layer Properties” dialog box that appears select the “Labels” tab
• Two-thirds down the dialog box is the “Text Symbol” box select the “Symbol” button

The “Symbol Selector” dialog box appears and you have some choices here but not much more than you did in the “Layer Properties” dialog box.

• Now select the “Properties” button and the “Editor” dialog box appears in this dialog box is a wealth of properties you can change to make your labels bold or soft. Go ahead and experiment with some I’ll wait.

Please close all of the dialog boxes before you continue

The next tip I would like to offer is stack labeling or the ability to label multiple fields from the same feature class one on top of the other. To do this we need to build an expression follow the instructions below:

• Right click on your feature class in the table of contents
• Select “Properties”
• In the “Layer Properties” dialog box that appears select the “Labels” tab

Half way down this page is the “Text String” box

• Go ahead and pick your first field you would like to label in the “Label Field” list box
• Now select the “Expression” button and the “Label expression” dialog box appears

In the “Label Fields” text area it says ”Double-click to add a field into the expression” so go ahead and select your second label field. Double click it so it is added to your “Expression” text area. Now we are not done yet don’t get excited if you try to click OK and close this dialog box you get a nice error message that says your expression has an error, how useful.

Now between your first and second field type everything between the quotes “ & vbnewline & ” so your expression should look something like this:

[OWNERNAME] & vbnewline & [TMS]

Now when you label this feature class your labels should be your first field selection on top of your second field selection. In the example I used my owner name field is on top of my tax map number field.

Taking labels a step further below the “Expression” text area there are some useful buttons one of those buttons is “Help”

Click the “Help” button this dialog box is full of valuable information to help you really make your labels fancy. Just a word of caution, try to remember what you are presenting in the map is the most important thing don’t get carried away with the labeling.