CustomExpression Class

A custom aggregate expression that can be applied to a data column or group/sorting criteria.

Namespace: DevExpress.DataAccess.Sql

Assembly: DevExpress.DataAccess.v20.1.dll

Declaration

public sealed class CustomExpression :
    ExpressionBase
Public NotInheritable Class CustomExpression
    Inherits ExpressionBase

Remarks

The following example illustrates how to create a simple CustomExpression. For general information on creating custom expressions, see Creating Criteria.


using DevExpress.DataAccess.ConnectionParameters;
using DevExpress.DataAccess.Sql;
// ...

private SqlDataSource BindToData() {
    // Create a data source with the required connection parameters.
    Access97ConnectionParameters connectionParameters =
    new Access97ConnectionParameters("../../Data/nwind.mdb", "", "");
    SqlDataSource ds = new SqlDataSource(connectionParameters);

    // Create a query and select a table.
    SelectQuery query = new SelectQuery("MyQuery");
    Table employeesTable = new Table() { Name = "Employees" };
    query.Tables.Add(employeesTable);

    // Create a custom expression.
    CustomExpression fullName = new CustomExpression();
    fullName.Expression = "[FirstName] + ' ' + [LastName]";

    // Select a column and assign the expression to it.
    Column column = new Column();
    column.Expression = fullName;
    column.Alias = "FullName";
    query.Columns.Add(column);

    // Add the query to the collection and return the data source.
    ds.Queries.Add(query);
    return ds;
}

Inheritance

Object
ExpressionBase
CustomExpression
See Also