Validate Decimal number in SQL Server using ISNUMERIC function

Hi tsakumar81,

Use the ISNUMERIC function.

Refer below example.

Stored Procdure

CREATE PROCEDURE ValidateIsNumber
    @RequestAmount VARCHAR(21)
As
	BEGIN
	IF ISNUMERIC(@RequestAmount) = 0 
	BEGIN
		SELECT 0 --INVALID
	END
	ELSE
	BEGIN
		SELECT 1 --VALID
	END
END

HTML

<asp:TextBox ID="txtNumber" runat="server" />
<asp:Button Text="Validate" runat="server" OnClick="OnValidate" />

Namespaces

C#

using System.Data;
using System.Data.SqlClient;
using System.Configuration;

VB.Net

Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration

Code

C#

protected void OnValidate(object sender, EventArgs e)
{
    string conString = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    string spName = "ValidateIsNumber";
    using (SqlConnection con = new SqlConnection(conString))
    {
        using (SqlCommand cmd = new SqlCommand(spName, con))
        {
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.Parameters.AddWithValue("@RequestAmount", txtNumber.Text);
            con.Open();
            bool isNumeric = Convert.ToBoolean(cmd.ExecuteScalar());
            con.Close();
            if (!isNumeric)
            {
                ClientScript.RegisterClientScriptBlock(this.GetType(), "", "alert('Invalid number.')", true);
            }
        }
    }
}

VB.Net

Protected Sub OnValidate(sender As Object, e As EventArgs)
    Dim conString As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Dim spName As String = "ValidateIsNumber"
    Using con As SqlConnection = New SqlConnection(conString)
        Using cmd As SqlCommand = New SqlCommand(spName, con)
            cmd.CommandType = CommandType.StoredProcedure
            cmd.Parameters.AddWithValue("@RequestAmount", txtNumber.Text)
            con.Open()
            Dim isNumeric As Boolean = Convert.ToBoolean(cmd.ExecuteScalar())
            con.Close()
            If Not isNumeric Then
                ClientScript.RegisterClientScriptBlock(Me.GetType(), "", "alert('Invalid number.')", True)
            End If
        End Using
    End Using
End Sub

Screenshot