6. Querying a
Table
6.1 Many Ways to Select
Records
6.2 Working with
Selected Records
6.3 Demo
Get a statistics about a table
6. Querying a
Table
6.1 Many Ways
to Select Records
Find 
simply searches through the records in
the table until it finds one with the particular attribute value you specify.
When a record is found, it is selected and highlighted. ArcView also scrolls
the table to ensure that the selected record is visible inside the table
window.
￭ Selecting records with the mouse or keyboard
The
Select tool 
can be used to select one or more
records from a table. Hold down Shift key to select multiple records.
￭ Selecting records using a query
Use the
Query Builder 
when you want to select records
according to their values. For example, you can build a query to select all the
records in which the value for a field named Price is greater or equal to
$1000. You can also build more complex queries. You can also use the Query
Builder to narrow down your selection from the set of records that is already
selected, and to add additional records to this set.
￭ Selecting records in a table by selecting features
on a view
When you are working with a theme's table, selecting or deselecting the theme's features in the view also selects or deselects the records for these features in the table.
￭ Selecting records using a chart
A chart contains one data marker for each selected record in the table. By erasing data markers in the chart you can deselect records in the table. In this way you can use the chart to focus in on particular records of interest. See Adding and erasing data markers on a chart.
6.2 Working with Selected Records
￭ Getting statistics about a table
Use the Statistics option from the Field menu to obtain statistics about a particular field's values in a table. Statistics displays information for either all records or the currently selected records. You can only perform statistics on numeric fields. The following statistics are reported: Sum, Count, Mean, Maximum, Minimum, Range, Variance, Standard deviation.
You can
summarize a table based on a particular field's values. The results are stored
in a new table. If some records in the table are currently selected, only these
records are summarized. If no records are selected, the whole table is
summarized.
Summarize creates one record in the new table for each unique value of the field you chose. Each record contains a count showing how many records in the table being summarized have this value. Each record also contains the result of any summary statistics you requested in the Summarize dialog box, such as the sum, minimum. maximum and standard deviation for any other field in table.
Find air
medical service company whose name starts with “Mercy”.
a. Make a theme
active
b. Open theme
table
c. From the
Table menu, choose Find, or click the Find button 
.
d. Type in the
attribute value you wish to find.
e. Press OK.
¨ Find will search the
table to find the first record with that attribute value.
Get a statistics about a table
Get a statistics of total population of census tracts for Erie county
a. Make a theme
active
b. Open theme
table
c. Make a
numeric field active by clicking the field bar
d. Choose
Statistics… from the Field menu
How many
fatal traffic crashes have occurred each month?
How many
fatalities have been involved each month?
a. Add a table
from Project window (Click Add button when highlighting table)
b. Click on the
field to make it active
c. Choose
Summarize… from the Field menu, or click Summarize button 
d. In the Summarize dialog box,
choose any related numeric field from the Fields list, Sum from the Summarize
by list, and then press Add button, then press OK.
You can
create the chart from the summary table as shown below.
Does a table
contain duplicate values for a unique identifier?
a. Click on the
field such as ID field to make it active
b. Click
Summarize button.
c. In the
Summarize dialog box, press OK. (This will automatically open a summary table)
d. Click the
Count field in a Summary table
e. Click the
Sort Descending button 
.
f.
Check to see if the value of Count field is greater than 1.