Java Examples - Use Column Methods

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Problem Description:

How to use different methods of column to Count no of columns, get column name, get column type etc ?

Solution:

Following example uses getColumnCount, getColumnName, getColumnTypeName, getColumnDisplaySize methods to get the no of columns, name of the column or type of the column in the table.

import java.sql.*;

public class jdbcConn {
   public static void main(String[] args) throws Exception{
      Class.forName("org.apache.derby.jdbc.ClientDriver");
      Connection con = DriverManager.getConnection
      ("jdbc:derby://localhost:1527/testDb","name","pass");
      Statement stmt = con.createStatement();
      String query = "select * from emp order by name";
      ResultSet rs = stmt.executeQuery(query);
      ResultSetMetaData rsmd = rs.getMetaData();
      System.out.println("no of columns in the table= "+
      rsmd.getColumnCount());
      System.out.println("Name of the first column "+ 
      rsmd.getColumnName(1));
      System.out.println("Type of the second column "+
      rsmd.getColumnTypeName(2));
      System.out.println("No of characters in 3rd column "+ 
      rsmd.getColumnDisplaySize(2));
   }
}

Result:

The above code sample will produce the following result.The result may vary.

no of columns in the table= 3
Name of the first columnID
Type of the second columnVARCHAR
No of characters in 3rd column20


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