/****************************************************************************
** (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: TbUse.cs
**
** SAMPLE: How to manipulate table data with the DB2 .Net Data Provider
** and connect to/disconnect from a database
**
** SQL Statements USED:
** SELECT
** INSERT
** UPDATE
** DELETE
**
** DB2 .NET Data Provider Classes USED:
** DB2Connection
** DB2Command
** DB2Transaction
**
**
*****************************************************************************
**
** Building and Running the sample program
**
** 1. Compile the TbUse.cs file with bldapp.bat by entering the following
** at the command prompt:
**
** bldapp TbUse
**
** or compile TbUse.cs with the makefile by entering the following at
** the command prompt:
**
** nmake TbUse
**
** 2. Run the TbUse program by entering the program name at the command
** prompt:
**
** TbUse
**
*****************************************************************************
**
** 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 TbUse
{
public static void Main(String[] args)
{
// Declare a DB2Command, a DB2Transaction and a DB2Connection
DB2Connection conn=null;
DB2Transaction trans= null;
DB2Command cmd = null;
try
{
Console.WriteLine();
Console.WriteLine(" THIS SAMPLE SHOWS HOW TO CONNECT TO/DISCONNECT" +
" FROM A DATABASE\n AND PERFORM BASIC DATABASE" +
" OPERATIONS.");
Console.WriteLine();
// Connect to a database
Console.WriteLine(" Connecting to a database ...");
conn = ConnectDb(args);
// Instantiate the DB2Command
trans=conn.BeginTransaction();
cmd = conn.CreateCommand();
cmd.Connection = conn;
cmd.Transaction = trans;
// Perform a query with the 'org' table
BasicQuery(conn,trans,cmd);
// Insert rows into the 'staff' table
BasicInsert(conn,trans,cmd);
trans=conn.BeginTransaction();
cmd.Transaction = trans;
// Update a set of rows in the 'staff' table
BasicUpdate(conn,trans,cmd);
trans=conn.BeginTransaction();
cmd.Transaction = trans;
// Delete a set of rows from the 'staff' table
BasicDelete(conn,trans,cmd);
// Disconnect from the database
Console.WriteLine("\n Disconnect from the database");
conn.Close();
}
catch (Exception e)
{
if( conn != null )
{
conn.Close();
trans.Rollback();
}
Console.WriteLine(e.Message);
}
} // Main
// This method demonstrates how to perform a standard query
public static void BasicQuery(DB2Connection conn,
DB2Transaction trans,
DB2Command cmd)
{
try
{
Console.WriteLine();
Console.WriteLine(
" ----------------------------------------------------------\n" +
" USE THE SQL STATEMENT:\n" +
" SELECT\n" +
" TO QUERY DATA FROM A TABLE.");
// Set up and execute the query
Console.WriteLine(
"\n Execute Statement:\n" +
" SELECT deptnumb, location FROM org WHERE deptnumb < 25");
cmd.CommandText = "SELECT deptnumb, location " +
" FROM org " +
" WHERE deptnumb < 25";
DB2DataReader reader = cmd.ExecuteReader();
Console.WriteLine();
Console.WriteLine(" Results:\n" +
" DEPTNUMB LOCATION\n" +
" -------- --------------");
Int16 deptnum = 0;
String location="";
// Output the results of the query
while(reader.Read())
{
deptnum = reader.GetInt16(0);
location = reader.GetString(1);
Console.WriteLine(" " +
Format(deptnum, 8) + " " +
Format(location, 14));
}
reader.Close();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
} // BasicQuery
// This method demonstrates how to insert rows into a table
public static void BasicInsert(DB2Connection conn,
DB2Transaction trans,
DB2Command cmd)
{
try
{
Console.WriteLine();
Console.WriteLine(
" ----------------------------------------------------------\n" +
" USE THE SQL STATEMENT:\n" +
" INSERT\n" +
" TO INSERT DATA INTO A TABLE USING VALUES.");
// Display contents of the 'staff' table before inserting rows
DisplayStaffTable(conn,cmd);
// Use the INSERT statement to insert data into the 'staff' table.
Console.WriteLine();
Console.WriteLine(
" Invoke the statement:\n" +
" INSERT INTO staff(id, name, dept, job, salary)\n" +
" VALUES(380, 'Pearce', 38, 'Clerk', 13217.50),\n" +
" (390, 'Hachey', 38, 'Mgr', 21270.00),\n" +
" (400, 'Wagland', 38, 'Clerk', 14575.00)");
cmd.CommandText = "INSERT INTO staff(id, name, dept, job, salary) " +
" VALUES (380, 'Pearce', 38, 'Clerk', 13217.50), "+
" (390, 'Hachey', 38, 'Mgr', 21270.00), " +
" (400, 'Wagland', 38, 'Clerk', 14575.00) ";
cmd.ExecuteNonQuery();
// Display the content in the 'staff' table after the INSERT.
DisplayStaffTable(conn,cmd);
// Rollback the transaction
trans.Rollback();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
trans.Rollback();
}
} // BasicInsert
// This method demonstrates how to update rows in a table
public static void BasicUpdate(DB2Connection conn,
DB2Transaction trans,
DB2Command cmd)
{
try
{
Console.WriteLine();
Console.WriteLine(
" ----------------------------------------------------------\n" +
" USE THE SQL STATEMENT:\n" +
" UPDATE\n" +
" TO UPDATE TABLE DATA USING A SUBQUERY IN THE 'SET' CLAUSE.");
// Display contents of the 'staff' table before updating
DisplayStaffTable(conn,cmd);
// Update the data of table 'staff' by using a subquery in the SET
// clause
Console.WriteLine();
Console.WriteLine(
" Invoke the statement:\n" +
" UPDATE staff\n" +
" SET salary = (SELECT MIN(salary)\n" +
" FROM staff\n" +
" WHERE id >= 310)\n" +
" WHERE id = 310");
cmd.CommandText = "UPDATE staff " +
" SET salary = (SELECT MIN(salary) " +
" FROM staff " +
" WHERE id >= 310) " +
" WHERE id = 310";
cmd.ExecuteNonQuery();
// Display the final content of the 'staff' table
DisplayStaffTable(conn,cmd);
trans.Rollback();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
trans.Rollback();
}
} // BasicUpdate
// This method demonstrates how to delete rows from a table
public static void BasicDelete(DB2Connection conn,
DB2Transaction trans,
DB2Command cmd)
{
try
{
Console.WriteLine();
Console.WriteLine(
" ----------------------------------------------------------\n" +
" USE THE SQL STATEMENT:\n" +
" DELETE\n" +
" TO DELETE TABLE DATA.");
// Display contents of the 'staff' table
DisplayStaffTable(conn,cmd);
// Delete rows from the 'staff' table where id >= 310 and
// salary > 20000
Console.WriteLine();
Console.WriteLine(
" Invoke the statement:\n" +
" DELETE FROM staff WHERE id >= 310 AND salary > 20000");
cmd.CommandText = "DELETE FROM staff " +
" WHERE id >= 310 " +
" AND salary > 20000";
cmd.ExecuteNonQuery();
// Display the final content of the 'staff' table
DisplayStaffTable(conn,cmd);
trans.Rollback();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
trans.Rollback();
}
} // BasicDelete
// 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
// Helping method: Display content from the 'staff' table
public static void DisplayStaffTable(DB2Connection conn, DB2Command cmd)
{
try
{
Int16 id = 0;
String name = null;
Int16 dept = 0;
String job = null;
Int16 years = 0;
Decimal salary = 0;
Decimal comm = 0;
Console.WriteLine();
Console.WriteLine(
" SELECT * FROM staff WHERE id >= 310\n\n" +
" ID NAME DEPT JOB YEARS SALARY COMM\n" +
" --- -------- ---- ----- ----- -------- --------");
cmd.CommandText = "SELECT * FROM staff WHERE id >= 310";
DB2DataReader reader = cmd.ExecuteReader();
while (reader.Read())
{
id = reader.GetInt16(0);
name = reader.GetString(1);
dept = reader.GetInt16(2);
job = reader.GetString(3);
if (reader.IsDBNull(4))
{
years = 0;
}
else
{
years = reader.GetInt16(4);
}
salary = reader.GetDecimal(5);
if ( reader.IsDBNull(6) )
{
comm = 0;
}
else
{
comm = reader.GetDecimal(6);
}
Console.Write(" " + Format(id, 3) +
" " + Format(name, 8) +
" " + Format(dept, 4));
if (job != null)
{
Console.Write(" " + Format(job, 5));
}
else
{
Console.Write(" -");
}
if (years != 0)
{
Console.Write(" " + Format(years, 5));
}
else
{
Console.Write(" -");
}
Console.Write(" " + Format(salary, 7, 2));
if (comm != 0)
{
Console.Write(" " + Format(comm, 7, 2));
}
else
{
Console.Write(" -");
}
Console.WriteLine();
}
reader.Close();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
} // DisplayStaffTable
// Helping method: This method takes a String and returns it with
// length 'finalLen'
public static String Format (String strData, int finalLen)
{
String finalStr;
if (finalLen <= strData.Length)
{
finalStr = strData.Substring(0, finalLen);
}
else
{
finalStr = strData;
for (int i = strData.Length; i < finalLen; i++)
{
finalStr = finalStr + " ";
}
}
return (finalStr);
} // Format(String, int)
// Helping method: This method takes an Int16 and returns it as a String
// with length 'finalLen'
public static String Format(Int16 intData, int finalLen)
{
String strData = intData.ToString();
String finalStr = null;
if (finalLen <= strData.Length)
{
finalStr = strData.Substring(0, finalLen);
}
else
{
finalStr = "";
for (int i = 0; i < finalLen - strData.Length; i++)
{
finalStr = finalStr + " ";
}
finalStr = finalStr + strData;
}
return (finalStr);
} // Format(Int16, int)
// Helping method: This method takes a Decimal and returns it as a String
// with a specified precision and scale
public static String Format(Decimal doubData, int precision, int scale)
{
Decimal dataRound = Decimal.Round(doubData,scale);
String strData = String.Format("{0:f"+scale+"}" ,dataRound);
// Prepare the final string
int finalLen = precision + 1;
String finalStr;
if (finalLen <= strData.Length)
{
finalStr = strData.Substring(0, finalLen);
}
else
{
finalStr = "";
for (int i = 0; i < finalLen - strData.Length; i++)
{
finalStr = finalStr + " ";
}
finalStr = finalStr + strData;
}
return (finalStr);
} // Format(Decimal, int, int)
} // TbUse