Performing Advanced Filtering

The RowFilter property of a DataView is similar to a WHERE clause in a SELECT statement. You can therefore use very powerful filter expressions in your DataView. For example, you can use AND, OR, NOT, IN, LIKE, comparison operators, arithmetic operators, wildcard characters (* and %), and aggregate functions.

Note 

For full details on how to use such filter expressions in your DataView objects, refer to the DataColumn .Expression property in the .NET online documentation.

Here's a simple example that uses the LIKE operator and the percent (%) wildcard character to filter rows with a CustomerName that starts with Fr:

 string filterExpression = "CompanyName LIKE 'Fr%'"; customersDV.RowFilter = filterExpression; 

Notice that the string Fr% is placed in single quotes-which you must do for all string literals. When this code replaces the existing code in the UsingDataView.cs program shown earlier in Listing 13.1, the output is as follows:

 FRANK Frankenversand Germany FRANR France restauration France FRANS Franchi S.p.A. Italy 

Note 

I've made this change in the UsingDataView2.cs program (the listing is omitted from this book for brevity). Feel free to examine and run this program.




Mastering C# Database Programming
Mastering the SAP Business Information Warehouse: Leveraging the Business Intelligence Capabilities of SAP NetWeaver
ISBN: 0764596373
EAN: 2147483647
Year: 2003
Pages: 181

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