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<title>psqlODBC HOWTO - C#</title>
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<h1>psqlODBC HOWTO - C#</h1>
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Author: Dave Page (dpage@postgresql.org)<br>
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Release Date: 12 April 2002<br>
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Description: Example based Mini-Howto on Accessing PostgreSQL from C#
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This document provides some sample code to get you started with C# & PostgreSQL.
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Requirements to get the code to work:
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<li>A C# Compiler.</li>
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<li>The Microsoft .NET Framework.</li>
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<li>The Microsoft ODBC .NET Data Provider.</li>
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<li>A PostgreSQL datasource.</li>
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The example code shown below may need some modification to make it actually work in your environment.
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There is one table used in the example:
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id serial,
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data text,
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accessed timestamp
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INSERT INTO csharptest(data, accessed) VALUES('Rows: 1', now());
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INSERT INTO csharptest(data, accessed) VALUES('Rows: 2', now());
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INSERT INTO csharptest(data, accessed) VALUES('Rows: 3', now());
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using Microsoft.Data.Odbc;
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static void Main(string[] args)
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// Setup a connection string
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string szConnect = "DSN=dsnname;" +
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// Attempt to open a connection
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OdbcConnection cnDB = new OdbcConnection(szConnect);
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// The following code demonstrates how to catch & report an ODBC exception.
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// To keep things simple, this is the only exception handling in this example.
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// Note: The ODBC data provider requests ODBC3 from the driver. At the time of
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// writing, the psqlODBC driver only supports ODBC2.5 - this will cause
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// an additional error, but will *not* throw an exception.
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catch (OdbcException ex)
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Console.WriteLine (ex.Message + "\n\n" + "StackTrace: \n\n" + ex.StackTrace);
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// Pause for the user to read the screen.
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Console.WriteLine("\nPress <RETURN> to continue...");
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DataSet dsDB = new DataSet();
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OdbcDataAdapter adDB = new OdbcDataAdapter();
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OdbcCommandBuilder cbDB = new OdbcCommandBuilder(adDB);
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adDB.SelectCommand = new OdbcCommand(
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"SELECT id, data, accessed FROM csharptest",
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// Display the record count
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Console.WriteLine("Table 'csharptest' contains {0} rows.\n",
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dsDB.Tables[0].Rows.Count);
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// List the columns (using a foreach loop)
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Console.WriteLine("Columns\n=======\n");
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foreach(DataColumn dcDB in dsDB.Tables[0].Columns)
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Console.WriteLine("{0} ({1})", dcDB.ColumnName, dcDB.DataType);
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Console.WriteLine("\n");
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// Iterate through the rows and display the data in the table (using a for loop).
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// Display the data column last for readability.
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Console.WriteLine("Data\n====\n");
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for(int i=0;i<dsDB.Tables[0].Rows.Count;i++){
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Console.WriteLine("id: {0}, accessed: {1}, data: {2}",
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dsDB.Tables[0].Rows[i]["id"],
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dsDB.Tables[0].Rows[i]["accessed"],
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dsDB.Tables[0].Rows[i]["data"]);
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// Add a new row to the table using the dataset
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// Create a new row on the existing dataset, then set the values and add the row
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Console.WriteLine("\nInserting a new row...");
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DataRow rwDB = dsDB.Tables[0].NewRow();
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int iRows = dsDB.Tables[0].Rows.Count + 1;
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rwDB["data"] = "Rows: " + iRows.ToString();
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rwDB["accessed"] = System.DateTime.Now;
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dsDB.Tables[0].Rows.Add(rwDB);
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// Delete a row from the table using a direct SQL query.
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// This method can also be used for direct INSERTs UPDATEs, CREATEs DROPs and more.
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Console.WriteLine("\nDeleting the row with the lowest ID...");
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OdbcCommand cmDB = new OdbcCommand(
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"DELETE FROM csharptest WHERE id = (SELECT min(id) FROM csharptest)",
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cmDB.ExecuteNonQuery();
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// Execute a scalar query
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cmDB = new OdbcCommand("SELECT max(id) FROM csharptest", cnDB);
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string szMax = cmDB.ExecuteScalar().ToString();
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Console.WriteLine("\nThe maximum value in the id column is now: {0}", szMax);
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// Pause for the user to read the screen.
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Console.WriteLine("\nPress <RETURN> to continue...");
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