ExecuteScalar Method

OracleCommand.ExecuteScalar Method ()

 

Executes the query, and returns the first column of the first row in the result set returned by the query as a .NET Framework data type. Extra columns or rows are ignored.

Namespace:   System.Data.OracleClient
Assembly:  System.Data.OracleClient (in System.Data.OracleClient.dll)

public override object ExecuteScalar()

Return Value

Type: System.Object

The first column of the first row in the result set as a .NET Framework data type, or a null reference if the result set is empty or the result is a REF CURSOR.

Use the ExecuteScalar method to retrieve a single value (for example, an aggregate value) from a database. This requires less code than using the ExecuteReader method, and then performing the operations necessary to generate the single value from the data returned by an OracleDataReader.

A typical ExecuteScalar query can be formatted as in the following C# example:

CommandText = "SELECT COUNT(*) FROM Region";
Int32 count = (int32) ExecuteScalar();

The following example creates an OracleCommand and then executes it using ExecuteScalar. The example is passed a string that is an SQL statement that returns an aggregate result, and a string to use to connect to the database.

public void CreateOracleCommand(string myScalarQuery, OracleConnection connection) 
 {
    OracleCommand command = new OracleCommand(myScalarQuery, connection);
    command.Connection.Open();
    command.ExecuteScalar();
    connection.Close();
 }

.NET Framework
Available since 1.1
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