User's Manual

DPCTrack2
Users Manual
21-6
Figure 21.3
21.1.2.4 Wildcard Characters (Matching Parts of Strings using “LIKE” and “NOT LIKE”)
In addition to building queries for an, exact selection criteria, you may also build queries
using wildcard characters to match a likeness. For example, you can build a query that
generates a list of all instruments whose description is “LIKE” (or contains the words),
“pressure” and “valve”. Whether the instrument’s description is “pressure relief valve” or
“pressure control valve”, it will appear on a list generated by the execution of this type of
advanced query.
When constructing these types of queries, you should substitute wildcard characters (%
or _ ) for the unknown parts of the string. If you know how many characters are in the
missing part of the string, you should use one or more underscore ( _ ) characters;
otherwise, the percent (%) character is appropriate.
To build the pressure valve query mentioned on the previous page, you would perform
the following steps:
1. Assuming that “pressure valve” is part of at least one instrument’s description, first
choose Description from the Selection Field Name drop-down list.
2. Select “LIKE” from the Operation drop-down list.
3. Type “%pressure%valve%” into the Selection Value field.
4. Finally, click the Add To Selection Criteria
button to move it into the Selection
Criteria During Query Execution box. Your screen will look like the one shown in
Figure 21.4.
5. Click the Execute
button to generate a query list showing all instruments with
“pressure valve” in their description.