//***************************************************************************
// (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.sqlj
//
// SAMPLE: How to get information about a table
//
// SQL Statements USED:
//         SELECT
//
// Classes used from Util.sqlj are:
//         Db
//         SqljException
//
//                           
// Output will vary depending on the JDBC driver connectivity used.
//***************************************************************************
//
// For more information on the sample programs, see the README file.
//
// For information on developing Java applications see the Developing Java Applications book.
//
// 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
//**************************************************************************/

import java.sql.*;
import sqlj.runtime.*;
import sqlj.runtime.ref.*;

#sql iterator TbInfo_Cursor(String, String, int, int);

class TbInfo
{
  public static void main(String argv[])
  {
    try
    {
      Db db = new Db(argv);
      String tableName;

      System.out.println();
      System.out.println(
        "THIS SAMPLE SHOWS HOW TO GET INFORMATION ABOUT A TABLE.");


      // connect to the 'sample' database
      db.getDefaultContext();

      // call the sample methods
      tableName = "STAFF";
      getSchemaName(tableName);
      getColumnInfo(tableName);

      // disconnect from the 'sample' database
      db.disconnect();
    }
    catch (Exception e)
    {
      SqljException sqljExc = new SqljException(e);
      sqljExc.handle();
    }
  } // main

  // This function demonstrates how to get the schema name for a table
  static void getSchemaName(String tableName)
  {
    try
    {
      String schemaName;

      System.out.println();
      System.out.println(
        "----------------------------------------------------------\n" +
        "USE THE SQL STATEMENT:\n" +
        "  SELECT INTO\n" +
        "TO GET A TABLE SCHEMA NAME.");

      // get the table schema name for a table
      System.out.println();
      System.out.println(
          "  Execute the statement:\n" +
          "    SELECT tabschema INTO :schemaName\n" +
          "      FROM syscat.tables\n" +
          "      WHERE tabname = :tableName\n" +
          "  for tableName = '" + tableName + "'.");

      #sql {SELECT tabschema INTO :schemaName
              FROM syscat.tables
              WHERE tabname = :tableName};

      System.out.println();
      System.out.println("  Table schema name is: " + schemaName);
    }
    catch (Exception e)
    {
      SqljException sqljExc = new SqljException(e);
      sqljExc.handle();
    }
  } // getSchemaName

  // This function demonstrates how to get the column information for a table
  static void getColumnInfo(String tableName)
  {
    try
    {
      TbInfo_Cursor cur;
      String colName = "", dataType = "";
      int dataLength = 0, dataScale = 0;

      System.out.println();
      System.out.println(
        "----------------------------------------------------------\n" +
        "USE THE SQL STATEMENTS:\n" +
        "  SELECT\n" +
        "  FETCH\n" +
        "TO GET TABLE COLUMN INFORMATION.");

      // get the column information for a table
      System.out.println();
      System.out.println(
        "  Get info for '" + tableName + "' table columns: ");
      System.out.println(
        "    column name          data type      data size\n" +
        "    -------------------- -------------- ----------");

      #sql cur = {SELECT colname, typename, length, scale
                    FROM syscat.columns
                    WHERE tabname = :tableName};

      #sql {FETCH :cur INTO :colName, :dataType, :dataLength, :dataScale};

      if (cur.endFetch())
      {
        System.out.println();
        System.out.println("  Data not found.\n");
      }

      while (!cur.endFetch())
      {
        System.out.print("    " + Data.format(colName,20) +
                         " " + Data.format(dataType,14) +
                         " " + dataLength);
        if (dataScale != 0)
        {
          System.out.println("," + dataScale);
        }
        else
        {
          System.out.println();
        }

        #sql {FETCH :cur INTO :colName, :dataType, :dataLength, :dataScale};
      }
      cur.close();
    }
    catch (Exception e)
    {
      SqljException sqljExc = new SqljException(e);
      sqljExc.handle();
    }
  } // getColumnInfo
} // TbInfo