'****************************************************************************
' (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: TbInfo.vb
'
' SAMPLE: How to get information about a table
' with the DB2 .Net Data Provider
'
' SQL Statements USED:
' SELECT
'
' DB2 .NET Data Provider Classes USED:
' DB2Connection
' DB2Command
'
'
'****************************************************************************
'
' Building and Running the sample program
'
' 1. Compile the TbInfo.vb file with bldapp.bat by entering the following
' at the command prompt:
'
' bldapp TbInfo
'
' or compile TbInfo.vb with the makefile by entering the following at
' the command prompt:
'
' nmake TbInfo
'
' 2. Run the TbInfo program by entering the program name at the command
' prompt:
'
' TbInfo
'
'****************************************************************************
'
' 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
'
'****************************************************************************
Imports System
Imports System.Data
Imports Microsoft.VisualBasic
Imports IBM.Data.DB2
Public Class TbInfo
Public Shared Sub Main(args() As String)
' Declare a DB2Connection
Dim conn As DB2Connection
Try
Console.WriteLine()
Console.WriteLine( _
" THIS SAMPLE SHOWS HOW TO GET INFORMATION ABOUT A TABLE.")
' Declare a String to store the table name
Dim tableName As String
Console.WriteLine()
' Connect to a database
Console.WriteLine(" Connecting to a database ...")
conn = ConnectDb(args)
tableName = "STAFF"
' Obtain the schema name for a table
GetSchemaName(conn, tableName)
' Obtain the column information for a table
GetColumnInfo(conn, tableName)
' Disconnect from the database
Console.WriteLine(vbNewLine & _
" Disconnect from the database.")
conn.Close()
Catch e As Exception
Console.WriteLine(e.Message)
If Not (conn is System.DBNull.value) Then
conn.Close()
End If
End Try
End Sub ' Main
' This method establishes a connection to a database
Public Shared Function ConnectDb(argv() As String) As DB2Connection
Dim server As String
Dim dbalias As String
Dim userId As String
Dim password As String
Dim portNumber As Int32 = -1
Dim connectString As String
If (argv.Length > 5) Then
Throw new Exception( _
"Usage: prog_name [dbAlias] [userId passwd]" & vbNewLine & _
" prog_name [dbAlias] server portNum userId passwd")
Else
If (argv.Length = 1) Then
If( String.Compare(argv(0),"?") = 0 Or _
String.Compare(argv(0),"-?") = 0 Or _
String.Compare(argv(0),"/?") = 0 Or _
String.Compare(argv(0),"-h",true) = 0 Or _
String.Compare(argv(0),"/h",true) = 0 Or _
String.Compare(argv(0),"-help",true) = 0 Or _
String.Compare(argv(0),"/help",true) = 0 ) Then
Throw new Exception( _
"Usage: prog_name [dbAlias] [userId passwd]" & vbNewLine & _
" prog_name [dbAlias] server portNum userId passwd")
End If
End If
End If
Select Case (argv.Length)
Case 0 ' Use all defaults
dbalias = "sample"
userId = ""
password = ""
Case 1 ' dbAlias specified
dbalias = argv(0)
userId = ""
password = ""
Case 2 ' userId & passwd specified
dbalias = "sample"
userId = argv(0)
password = argv(1)
Case 3 ' dbAlias, userId & passwd specified
dbalias = argv(0)
userId = argv(1)
password = argv(2)
Case 4 ' use default dbAlias
dbalias = "sample"
server = argv(0)
portNumber = Convert.ToInt32(argv(1))
userId = argv(2)
password = argv(3)
Case 5 ' everything specified
dbalias = argv(0)
server = argv(1)
portNumber = Convert.ToInt32(argv(2))
userId = argv(3)
password = argv(4)
End Select
If(portNumber = -1) Then
connectString = "Database=" & dbalias
Else
connectString = "Server=" & server & ":" & portNumber & _
";Database=" & dbalias
End If
If (userId <> "")
connectString += ";UID=" & userId & ";PWD=" & password
End If
Dim conn As DB2Connection = new DB2Connection(connectString)
conn.Open()
Console.WriteLine(" Connected to the " & dbalias & " database")
Return conn
End Function ' ConnectDb
' This method demonstrates how to get the schema name for a table
Public Shared Sub GetSchemaName(conn As DB2Connection, tableName As String)
Console.WriteLine()
Console.WriteLine( _
" ----------------------------------------------------------" & _
vbNewLine & _
" USE THE SQL STATEMENT:" & vbNewLine & _
" SELECT" & vbNewLine & _
" TO GET THE SCHEMA NAME OF A TABLE.")
Try
' Get the schema name for a table and display it
Console.WriteLine()
Console.WriteLine( _
" Execute the statement:" & vbNewLine & _
" SELECT tabschema" & vbNewLine & _
" FROM syscat.tables" & vbNewLine & _
" WHERE tabname = '" & tableName & "'")
Dim cmd As DB2Command = conn.CreateCommand()
cmd.CommandText = "SELECT tabschema " & _
" FROM syscat.tables " & _
" WHERE tabname = '" & tableName & "'"
Dim reader As DB2DataReader = cmd.ExecuteReader()
reader.Read()
Console.WriteLine()
Console.WriteLine(" Table schema name is: " & reader.GetString(0))
reader.Close()
Catch e As Exception
Console.WriteLine(e.Message)
End Try
End Sub ' GetSchemaName
' This method demonstrates how to get the column information for a table
Public Shared Sub GetColumnInfo(conn As DB2Connection, tableName As String)
Dim dataColname As String = ""
Dim dataTypename As String= ""
Dim dataLength As Int32 = 0
Dim dataScale As Int32 = 0
Console.WriteLine()
Console.WriteLine( _
" ----------------------------------------------------------" & _
vbNewLine & _
" USE THE SQL STATEMENTS:" & vbNewLine & _
" SELECT" & vbNewLine & _
" TO GET THE COLUMN INFORMATION OF A TABLE.")
Try
' Get the column information for a table
Console.WriteLine()
Console.WriteLine( _
" The following SQL statement gets the column information " & _
vbNewLine & _
" of the '" & tableName & "' table: " & vbNewLine)
Console.WriteLine( _
" SELECT colname, typename, length, scale " & vbNewLine & _
" FROM syscat.columns " & vbNewLine & _
" WHERE tabname = '" & tableName & "'" & vbNewLine)
Console.WriteLine( _
" column name data type data size" & vbNewLine & _
" -------------------- -------------- ----------")
' Create a DB2Command to execute the SQL statement
Dim cmd As DB2Command = conn.CreateCommand()
cmd.CommandText = "SELECT colname, typename, length, scale " & _
" FROM syscat.columns " & _
" WHERE tabname = '" & tableName & "'" & vbNewLine
Dim reader As DB2DataReader = cmd.ExecuteReader()
' Check if the query returned no data
If (Equals(reader.Read(), false)) Then
Console.WriteLine()
Console.WriteLine(" Data not found." & vbNewLine)
End If
' Retrieve and display the column information from the DB2DataReader
Do While reader.Read()
dataColname = reader.GetString(0)
dataTypename = reader.GetString(1)
dataLength = reader.GetInt32(2)
dataScale = reader.GetInt16(3)
Console.Write(" " & dataColname.PadRight(20) & _
" " & dataTypename.PadRight(14) & _
" " & dataLength)
If (NOT Equals(dataScale,0)) Then
Console.WriteLine("," & dataScale)
Else
Console.WriteLine()
End If
Loop
reader.Close()
Catch e As Exception
Console.WriteLine(e.Message)
End Try
End Sub ' GetColumnInfo
End Class ' TbInfo