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QuickOPC.NET
Product Version 5.1
Application Note
How to log OPC Data Access item changes into an SQL database
It is often required that a status of certain process variable is logged into a SQL database. Following example shows how to do that with QuickOPC:
// SimpleLogToSql: Logs OPC Data Access item changes into an SQL database, using a subscription.
// The database creation script is in the QuickOPCExamples.sql file. The examples that the database is already created.
using System;
using System.Data;
using System.Data.SqlClient;
using OpcLabs.EasyOpc.DataAccess;
namespace SimpleLogToSql
{
class Program
{
static void Main()
{
const string connectionString =
"Data Source=(local);Initial Catalog=QuickOPCExamples;Integrated Security=true";
Console.WriteLine("Starting up...");
using (var connection = new SqlConnection(connectionString))
{
connection.Open();
// Create all necessary ADO.NET objects.
var adapter = new SqlDataAdapter("SELECT * FROM SimpleLog", connection);
var dataSet = new DataSet();
adapter.FillSchema(dataSet, SchemaType.Source, "SimpleLog");
adapter.InsertCommand = new SqlCommandBuilder(adapter).GetInsertCommand();
DataTable table = dataSet.Tables["SimpleLog"];
CODE Consulting and Development, s.r.o. , Bolevecka naves 27, 323 00 Plzen, Czech Republic
e-mail: [email protected], Web: www.opclabs.com, tel. +420 603 214 412, fax +420 378 600 795
QuickOPC.NET-7-How to log OPC Data Access item changes into an SQL database.docx; 2013-11-21
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QuickOPC.NET
Product Version 5.1
Application Note
Console.WriteLine("Logging for 30 seconds...");
// Subscribe to an OPC item, using an anonymous method to process the notifications.
int handle = EasyDAClient.DefaultInstance.SubscribeItem(
"",
"OPCLabs.KitServer.2",
"Simulation.Incrementing (1 s)",
100,
(_, eventArgs) =>
{
Console.Write(".");
// In this example, we only log valid data. Production logger would also log errors.
if (eventArgs.Vtq != null)
{
// Fill a DataRow with the OPC data, and add it to a DataTable.
table.Rows.Clear();
DataRow row = table.NewRow();
row["ItemID"] = eventArgs.ItemDescriptor.ItemId;
row["Value"] = eventArgs.Vtq.Value;
row["Timestamp"] = eventArgs.Vtq.Timestamp;
row["Quality"] = (short)eventArgs.Vtq.Quality;
table.Rows.Add(row);
// Update the underlying DataSet using an insert command.
adapter.Update(dataSet, "SimpleLog");
}
}
);
System.Threading.Thread.Sleep(30*1000);
Console.WriteLine();
Console.WriteLine("Shutting down...");
EasyDAClient.DefaultInstance.UnsubscribeItem(handle);
}
Console.WriteLine("Finished.");
CODE Consulting and Development, s.r.o. , Bolevecka naves 27, 323 00 Plzen, Czech Republic
e-mail: [email protected], Web: www.opclabs.com, tel. +420 603 214 412, fax +420 378 600 795
QuickOPC.NET-7-How to log OPC Data Access item changes into an SQL database.docx; 2013-11-21
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QuickOPC.NET
Product Version 5.1
Application Note
}
}
}
The database creation script is here:
-- Creates a database with tables needed to run QuickOPC examples.
CREATE DATABASE QuickOPCExamples;
GO
USE QuickOPCExamples;
GO
CREATE TABLE SimpleLog(
ItemID nvarchar(50) NULL,
Value sql_variant NULL,
[Timestamp] datetime NULL,
Quality int NULL
);
GO
CODE Consulting and Development, s.r.o. , Bolevecka naves 27, 323 00 Plzen, Czech Republic
e-mail: [email protected], Web: www.opclabs.com, tel. +420 603 214 412, fax +420 378 600 795
QuickOPC.NET-7-How to log OPC Data Access item changes into an SQL database.docx; 2013-11-21
Page 3 of 5
QuickOPC.NET
Product Version 5.1
Application Note
And (part of) the resulting data may look like this:
This example will be included with the product starting with build 5.12.1305.1. Please use the example from the product itself for the most up-to-date code of the example.
General information about integration of QuickOPC and Microsoft SQL Server is here.
CODE Consulting and Development, s.r.o. , Bolevecka naves 27, 323 00 Plzen, Czech Republic
e-mail: [email protected], Web: www.opclabs.com, tel. +420 603 214 412, fax +420 378 600 795
QuickOPC.NET-7-How to log OPC Data Access item changes into an SQL database.docx; 2013-11-21
Page 4 of 5
QuickOPC.NET
Product Version 5.1
Application Note
OPC Alarms and Events notifications can be logged using the same approach, with EasyAEClient component.
Update: The original example (SimpleLogToSql) stores values of all data types in a single SQL_VARIANT column. As of build 5.12.1309.1, we are including two additional
examples of SQL logging with the product:


LogAsString: Values of all data types are stored in a single NVARCHAR column.
LogAsUnion: Values of all data types are stored in separate columns.
CODE Consulting and Development, s.r.o. , Bolevecka naves 27, 323 00 Plzen, Czech Republic
e-mail: [email protected], Web: www.opclabs.com, tel. +420 603 214 412, fax +420 378 600 795
QuickOPC.NET-7-How to log OPC Data Access item changes into an SQL database.docx; 2013-11-21
Page 5 of 5