SqlCommand.ExecuteScalar Method

public:
 override System::Object ^ ExecuteScalar();

public override object ExecuteScalar();

override this.ExecuteScalar : unit -> obj

Public Overrides Function ExecuteScalar () As Object

Returns

The first column of the first row in the result set, or a null reference (Nothing in Visual Basic) if the result set is empty. Returns a maximum of 2033 characters.

Exceptions

Examples

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

cmd.CommandText = "SELECT COUNT(*) FROM dbo.region";
Int32 count = (Int32) cmd.ExecuteScalar();

The following example creates a SqlCommand and then executes it using ExecuteScalar(). The example is passed a string representing a new value to be inserted into a table, and a string to use to connect to the data source. The function returns the new Identity column value if a new row was inserted, 0 on failure. >

using System;
using System.Data;
using Microsoft.Data.SqlClient;

public class Sample
{
    public void CreateSqlCommand(string queryString, SqlConnection connection)
    {
        SqlCommand command = new SqlCommand(queryString, connection);
        command.Connection.Open();
        command.ExecuteScalar();
        connection.Close();
    }
}

Remarks

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 that you need to generate the single value using the data returned by a SqlDataReader.