/****************************************************************************
** (c) Copyright IBM Corp. 2007 All rights reserved.
**
** The following sample of source code ("Sample") is owned by International
** Business Machines Corporation or one of its subsidiaries ("IBM") and is
** copyrighted and licensed, not sold. You may use, copy, modify, and
** distribute the Sample in any form without payment to IBM, for the purpose of
** assisting you in the development of your applications.
**
** The Sample code is provided to you on an "AS IS" basis, without warranty of
** any kind. IBM HEREBY EXPRESSLY DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR
** IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Some jurisdictions do
** not allow for the exclusion or limitation of implied warranties, so the above
** limitations or exclusions may not apply to you. IBM shall not be liable for
** any damages you suffer as a result of using, copying, modifying or
** distributing the Sample, even if IBM has been advised of the possibility of
** such damages.
*****************************************************************************
**
** SOURCE FILE NAME: DbEvent.cs
**
** SAMPLE: How to use DB2DataAdapter events: RowUpdating and RowUpdated
** with the DB2 .Net Data Provider
**
** SQL Statements USED:
** CREATE TABLE
** DROP TABLE
** INSERT
** SELECT
**
** DB2 .NET Data Provider Classes USED:
** DB2Connection
** DB2Command
**
**
*****************************************************************************
**
** Building and Running the sample program
**
** 1. Compile the DbEvent.cs file with bldapp.bat by entering the following
** at the command prompt:
**
** bldapp DbEvent
**
** or compile DbEvent.cs with the makefile by entering the following at
** the command prompt:
**
** nmake DbEvent
**
** 2. Run the DbEvent program by entering the program name at the command
** prompt:
**
** DbEvent
**
*****************************************************************************
**
** For more information on the sample programs, see the README file.
**
** For information on developing applications, see the Application
** Development Guide.
**
** For information on using SQL statements, see the SQL Reference.
**
** For the latest information on programming, compiling, and running DB2
** applications, visit the DB2 Information Center at
** http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp
**
****************************************************************************/
using System;
using System.Data;
using System.IO;
using IBM.Data.DB2;
class DbEvent
{
public static void Main(String[] args)
{
// Declare a DB2Connection and a DB2Command
DB2Connection conn = null;
DB2Command cmd = null;
try
{
Console.WriteLine();
Console.WriteLine(" THIS SAMPLE SHOWS HOW TO USE DB2DataAdapter " +
"EVENTS:\n RowUpdating and RowUpdated");
Console.WriteLine();
// Connect to a database
Console.WriteLine(" Connecting to a database ...");
conn = ConnectDb(args);
// Create a DB2DataAdapter, a DB2CommandBuilder and a DataSet
DB2DataAdapter adp = new DB2DataAdapter();
DB2CommandBuilder cb = null;
DataSet dset = new DataSet();
cmd = conn.CreateCommand();
// Create a table 'empsamp' in the SAMPLE database
Console.WriteLine("\n CREATE A TABLE empsamp WITH ATTRIBUTES:\n" +
" ID SMALLINT NOT NULL,\n" +
" NAME VARCHAR(9),\n" +
" JOB CHAR(5),\n" +
" SALARY DEC(7,2),\n" +
" PRIMARY KEY(ID)");
cmd.CommandText = "CREATE TABLE EMPSAMP (" +
" ID SMALLINT NOT NULL," +
" NAME VARCHAR(9)," +
" JOB CHAR(5)," +
" SALARY DEC(7,2)," +
" PRIMARY KEY(ID))";
cmd.ExecuteNonQuery();
Console.WriteLine();
// Insert some rows in the empty table 'empsamp'
Console.WriteLine(
" INSERT THE FOLLOWING ROWS IN EMPSAMP:\n" +
" (270, 'EMP1', 'CLERK', 4500),\n" +
" (280, 'EMP2', 'MGR', 13500.50),\n" +
" (290, 'EMP3', 'SALES', 11000.40)");
cmd.CommandText =
"INSERT INTO empsamp(id, name, job, salary) " +
" VALUES (270, 'EMP1', 'CLERK', 4500), "+
" (280, 'EMP2', 'MGR', 13500.50), " +
" (290, 'EMP3', 'SALES', 11000.40) ";
Console.WriteLine();
cmd.ExecuteNonQuery();
// Intialize the SELECT command of the DB2DataAdapter
adp.SelectCommand = new DB2Command("SELECT * FROM empsamp",conn);
Console.WriteLine("\n USE CLASS DB2CommandBuilder TO GENERATE" +
" THE INSERT, UPDATE AND DELETE\n" +
" COMMANDS FOR THE DB2DataAdapter");
// Initialize a DB2CommandBuilder instance that generates the UPDATE,
// DELETE and INSERT commands for the DB2DataAdapter
cb = new DB2CommandBuilder(adp);
// Define the parameters for the generated UPDATE, DELETE and INSERT
// commands of the DB2DataAdapter
AddParameters(cb);
Console.WriteLine("\n " +
"FILL THE DATASET WITH THE Fill METHOD OF " +
"DB2DataAdapter");
// Fill the DataSet with the data in table 'empsamp'
adp.Fill(dset,"empsamp");
// Make changes to the DataSet and respond to the RowUpdating and
// RowUpdated events raised before and after the Update() method of
// DB2DataAdapter is processed for each row
EventHandler(adp,dset);
// Drop the table 'empsamp'
cmd.CommandText = "DROP TABLE empsamp";
cmd.ExecuteNonQuery();
// Disconnect from the database
Console.WriteLine("\n Disconnect from the database");
conn.Close();
}
catch(Exception e)
{
cmd.CommandText = "DROP TABLE empsamp";
cmd.ExecuteNonQuery();
conn.Close();
Console.WriteLine(e.Message);
}
}
// Helper method: This method establishes a connection to a database
public static DB2Connection ConnectDb(String[] argv)
{
String server = "";
String alias = "";
String userId = "";
String password = "";
Int32 portNumber = -1;
String connectString;
if( argv.Length > 5 ||
( argv.Length == 1 &&
( String.Compare(argv[0],"?") == 0 ||
String.Compare(argv[0],"-?") == 0 ||
String.Compare(argv[0],"/?") == 0 ||
String.Compare(argv[0],"-h",true) == 0 ||
String.Compare(argv[0],"/h",true) == 0 ||
String.Compare(argv[0],"-help",true) == 0 ||
String.Compare(argv[0],"/help",true) == 0 ) ) )
{
throw new Exception(
"Usage: prog_name [dbAlias] [userId passwd] \n" +
" prog_name [dbAlias] server portNum userId passwd");
}
switch (argv.Length)
{
case 0: // Use all defaults
alias = "sample";
userId = "";
password = "";
break;
case 1: // dbAlias specified
alias = argv[0];
userId = "";
password = "";
break;
case 2: // userId & passwd specified
alias = "sample";
userId = argv[0];
password = argv[1];
break;
case 3: // dbAlias, userId & passwd specified
alias = argv[0];
userId = argv[1];
password = argv[2];
break;
case 4: // use default dbAlias
alias = "sample";
server = argv[0];
portNumber = Convert.ToInt32(argv[1]);
userId = argv[2];
password = argv[3];
break;
case 5: // everything specified
alias = argv[0];
server = argv[1];
portNumber = Convert.ToInt32(argv[2]);
userId = argv[3];
password = argv[4];
break;
}
if(portNumber==-1)
{
connectString = "Database=" + alias;
}
else
{
connectString = "Server=" + server + ":" + portNumber +
";Database=" + alias;
}
if(userId != "")
{
connectString += ";UID=" + userId + ";PWD=" + password;
}
DB2Connection conn = new DB2Connection(connectString);
conn.Open();
Console.WriteLine(" Connected to the " + alias + " database");
return conn;
} // ConnectDb
// This method defines the parameters for the UPDATE, DELETE and INSERT
// commands of the DB2DataAdapter
public static void AddParameters(DB2CommandBuilder cb)
{
try
{
// Define the parameters for the INSERT command in different ways
cb.GetInsertCommand().Parameters.Add("@empid",
DB2Type.SmallInt,
5,
"ID").SourceVersion =
DataRowVersion.Original;
cb.GetInsertCommand().Parameters.Add(
new DB2Parameter("@empname",
DB2Type.VarChar,
9,
ParameterDirection.Input,
false,
0,
0,
"NAME",
DataRowVersion.Current,
""));
cb.GetInsertCommand().Parameters.Add(new DB2Parameter("@empjob",
DB2Type.Char,
5,
"JOB"));
cb.GetInsertCommand().Parameters.Add("@empsalary",
DB2Type.Decimal,
7);
// Define the parameters for the UPDATE command in different ways
cb.GetUpdateCommand().Parameters.Add(
new DB2Parameter("@empname", DB2Type.VarChar, 9));
cb.GetUpdateCommand().Parameters.Add("@empsalary",
DB2Type.Decimal,
7,
"SALARY");
cb.GetUpdateCommand().Parameters.Add("@empid",
DB2Type.SmallInt,
5).SourceVersion =
DataRowVersion.Original;
DB2Parameter param = new DB2Parameter("@empjob", DB2Type.Char);
cb.GetUpdateCommand().Parameters.Add(param);
// Define the parameter for the DELETE command
cb.GetDeleteCommand().Parameters.Add("@empid",
DB2Type.SmallInt).SourceVersion =
DataRowVersion.Original;
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
} // AddParameters
// This method creates and demonstrates the use of event handlers
public static void EventHandler(DB2DataAdapter adp, DataSet dset)
{
try
{
// Add event handlers.
adp.RowUpdating += new DB2RowUpdatingEventHandler(UpdatingRow);
adp.RowUpdated += new DB2RowUpdatedEventHandler(UpdatedRow);
// Make changes to the DataSet
Console.WriteLine("\n MAKE CHANGES TO THE DATASET");
int i;
for(i=0; i<dset.Tables["empsamp"].Rows.Count; i++)
{
if(((Int16)dset.Tables["empsamp"].Rows[i]["id"]) == 270)
{
dset.Tables["empsamp"].Rows[i]["name"] = "LARRY";
dset.Tables["empsamp"].Rows[i]["job"] = "MGR";
dset.Tables["empsamp"].Rows[i]["salary"] = 3500;
break;
}
}
for(i=0; i<dset.Tables["empsamp"].Rows.Count; i++)
{
if(((Int16)dset.Tables["empsamp"].Rows[i]["id"]) == 290)
{
dset.Tables["empsamp"].Rows[i].Delete();
break;
}
}
// Update 'empsamp' to reflect the changes made to the Dataset
// and in the process, raise events: RowUpdating and RowUpdated
Console.WriteLine("\n " +
"UPDATE 'empsamp' TO REFLECT CHANGES MADE TO THE" +
" DATASET,\n IN THE PROCESS INVOKING EVENTS: " +
"RowUpdating and RowUpdated");
adp.Update(dset,"empsamp");
Console.WriteLine("\n EMPSAMP UPDATED");
// Remove event handlers.
adp.RowUpdating -= new DB2RowUpdatingEventHandler(UpdatingRow);
adp.RowUpdated -= new DB2RowUpdatedEventHandler(UpdatedRow);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
} // EventHandler
// This method handles the 'RowUpdating' event
public static void UpdatingRow(Object sender, DB2RowUpdatingEventArgs args)
{
// Display what type of operation is to be performed
Console.WriteLine("\n EVENT: RowUpdating");
Console.WriteLine("\n ATTEMPTING TO " +
args.StatementType.ToString().ToUpper() +
" THIS ROW\n");
// Display contents of the row before it is updated or deleted
if (args.StatementType == StatementType.Delete ||
args.StatementType == StatementType.Update)
{
DisplayRow(args.Row,DataRowVersion.Original);
}
} // UpdatingRow
// This method handles the 'RowUpdated' event
public static void UpdatedRow(Object sender, DB2RowUpdatedEventArgs args)
{
Console.WriteLine("\n EVENT: RowUpdated");
// Check if errors occured when the row was being updated
if (args.Status == UpdateStatus.ErrorsOccurred)
{
// Skip updating this row and proceed to updating the next row
Console.WriteLine("\n AN ERROR OCCURRED WHILE UPDATING THIS ROW");
args.Row.RowError = args.Errors.Message;
args.Status = UpdateStatus.SkipCurrentRow;
}
else
{
Console.WriteLine("\n THE " +
args.StatementType.ToString().ToUpper() +
" OPERATION WAS PERFORMED SUCCESFULLY");
// Display contents of the row after if has been updated
if(args.StatementType == StatementType.Update)
{
Console.WriteLine("\n DETAILS OF ROW AFTER UPDATE:\n");
DisplayRow(args.Row,DataRowVersion.Current);
}
}
} // UpdatedRow
// Helper method: This method displays the contents of a DataRow
public static void DisplayRow(DataRow row, DataRowVersion version)
{
// Obtain the DataTable corresponding to the DataRow
DataTable table = row.Table;
// Display column names
Console.Write(" ");
foreach(DataColumn col in table.Columns)
{
Console.Write(" " + col.ColumnName);
}
Console.WriteLine();
Console.Write(" ");
foreach(DataColumn col in table.Columns)
{
int length = 8;
if(col.DataType == Type.GetType("System.Int32") ||
col.DataType == Type.GetType("System.Int16"))
{
length = 3;
}
else if(col.DataType == Type.GetType("System.String"))
{
length = 7;
}
for(int i = 0; i < length; i++)
{
Console.Write("-");
}
Console.Write(" ");
}
Console.WriteLine();
Console.Write(" ");
// Display column entries of each row
foreach(DataColumn col in table.Columns)
{
Object data = row[col.ColumnName, version];
if(data is Int32 || data is Int16)
{
Console.Write(" " + data.ToString().PadRight(3));
}
else if (data is String)
{
Console.Write(" " + ((String)data).PadRight(7));
}
else
{
String str = String.Format("{0:f2}" ,data);
Console.Write(" " + str.PadLeft(8));
}
}
Console.WriteLine();
} // DisplayRow
} // DbEvent