QueryParameter Class
A parameter passed to a SqlQuery.
Namespace: DevExpress.DataAccess.Sql
Assembly: DevExpress.DataAccess.v19.1.dll
Declaration
Remarks
A collection of QueryParameter objects is returned by the SqlQuery.Parameters property. This property is also available for the StoredProcQuery class.
The following code illustrates how to bind to a Microsoft SQL Server database and filter the result set of a query by a specified parameter value.
using DevExpress.DataAccess.ConnectionParameters;
using DevExpress.DataAccess.Sql;
// ...
private SqlDataSource BindToData(int parameterValue) {
// Specify parameters required to connect to a specific data provider.
MsSqlConnectionParameters connectionParameters =
new MsSqlConnectionParameters("ServerName", "DataBaseName", null, null, MsSqlAuthorizationType.Windows);
// Create a data source instance with the specified connection parameters.
SqlDataSource ds = new SqlDataSource(connectionParameters);
// Create a query to access fields of the Products data table.
// End the chain by calling the Build method with a specified query name.
SelectQuery query = SelectQueryFluentBuilder
.AddTable("Products")
.SelectColumns("CategoryID", "ProductName")
.Build("Products");
// Create a query parameter of a required type and assign a value to it.
QueryParameter parameter = new QueryParameter() {
Name = "catID",
Type = typeof(System.Int32),
Value = parameterValue
};
query.Parameters.Add(parameter);
// Filter the query result set using the created parameter.
query.FilterString = "CategoryID = ?catID";
// Add the query and fill the data source.
ds.Queries.Add(query);
ds.Fill();
return ds;
}
To learn how to link query parameters with report or dashboard parameters using an Expression, refer to the following tutorials.
- Reporting - Filtering Data at the Data Source Level (Runtime Sample)
- Dashboards - How to: Pass a Dashboard Parameter to a Custom SQL Query in Code
Implements
Inheritance
Object
DataSourceParameterBase
QueryParameter
See Also