code: public static boolean addColumn (
          Connection conn, String table, String cname, String cdef, String afterCname)
          throws SQLException
      {
          if (tableContainsColumn(conn, table, cname)) {
  //             Log.info("Database table '" + table + "' already has column '" + cname + "'.");
              return false;
          }
  
          String update = "ALTER TABLE " + table + " ADD COLUMN " + cname + " " + cdef;
          if (afterCname != null) {
              update += " AFTER " + afterCname;
          }
          PreparedStatement stmt = null;
          try {
              stmt = conn.prepareStatement(update);
              stmt.executeUpdate();
          } finally {
              close(stmt);
          }
          log.info("Database column '" + cname + "' added to table '" + table + "'.");
          return true;
      }
docs: Adds a column (with name 'cname' and definition 'cdef') to the specified table.
  
  @param afterCname (optional) the name of the column after which to add the new column.
  
  @return true if the column was added, false if it already existed.