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