You're right, there are several ways to do this, using Excel to add columns and delete rows is not one of them. If it were me, I'd use a JOIN. A join doesn't change the existing data, it adds, or JOINS, an external file such as xlsx, xls, mdb. Other file types are also viable, I listed what i felt were the most common. Here's an explanation of how a Join would work.
Example: Using your uploaded image, row 1 of your shapefile table shows name=>278-PO-14-5-EB-A. Your external spreadsheet might have 240 rows and 3 columns. Your column headings might be a) ID, b) Condition, and c) Type. The column named ID in the spreadsheet would contain the same values as the NAME column from your shapefile. Condition and Type columns would be your new data. Condition=>good, fair, poor, or needs replacement. Type=>large medium, or small.
If a row in your spreadsheet contained a row with a) 278-PO-14-5-EB-A, b) Fair, c) Large, then Fair and Large would be added directly onto row 1 of your shapefile table and correspond to row 1's geometry. However, if your external spreadsheet does not have 27-PO-14-5-EB-A then the new columns in row 1 would be null and blank.
I'd keep the those extra columns you claim you don't need because I can work around them. If I really wanted to, I could delete them. Deleting them though, cannot be done using Excel.
Creating a JOIN does not change the existing shapefile geometry nor the existing shapefile data, it simply adds, or JOINS, additional data that's stored in an external file. Once you have the new data joined you can use this new data to isolate and label.
Examples: You may perform operations using the new data, such as:
- Isolate all records with condition classified as 'needs replacement'
- You may isolate and label the Type classified as 'Large' and use the NAME as an ID label for those large objects
- You may use three different colors to differentiate between good, fair and poor
As you can see, the new data has enhanced the existing data and that increases your analytical capacity and your ability to efficiently draw high impact maps. All this is possible using an external file.
Chicagolooper
