Building a Client/Server Application - Java Database Programming Bible - page 301

centerPanel.add(featuresPanel,BorderLayout.CENTER);
getContentPane().add(centerPanel,BorderLayout.CENTER);
}
}

Clearly, this example illustrates only a small percentage of the data available through the use of the
DatabaseMetaData object. It is well worth referring to the Javadocs available on the Sun Web site at:
http://java.sun.com/j2se/1.4/docs/api/java/sql/package-summary.html .

Note

A shorter link is http://java.sun.com/docs/ . This takes you to he main Javadocs
page, and you can navigate from there.

In addition to DatabaseMetaData methods, JDBC provides a large number of useful methods for
accessing information about the ResultSet returned by a query. The next section discusses these
methods.

Using ResultSetMetaData

The ResultSetMetaData object is similar to the DatabaseMetaData object, with the exception that
it returns information specific to the columns in a ResultSet .

Information about the columns in a ResultSet is available by calling the getMetaData() method on
the ResultSet. The ResultSetMetaData object returned gives the number, types, and properties of its
ResultSet object's columns.

Table 10-3 shows some of the more commonly used methods of the ResultSetMetaData object.
Table 10-3: ResultSetMetaData Methods

ResultSetMetaData method Description

getColumnCount() Returns the number of columns in the ResultSet

getColumnDisplaySize(int column)

Returns the column's max width in chars

getColumnLabel(int column)

Returns the column title for use in displays

getColumnName(int column)

Returns the column name

getColumnType(int column)

Returns the column's SQL data-type index

getColumnTypeName(int column) Returns the name of the column's SQL data type

getPrecision(int column) Returns the number of decimal digits in the column

getScale(int column) Returns the number of digits to the right of the

decimal point

getTableName(int column) Returns the table name

isAutoIncrement(int column)

Returns true if the column is autonumbered

isCurrency(int column) Returns true if the column value is a currency value

isNullable(int column)

Returns true if the column value can be set to NULL

Listing 10-9 illustrates the use of the ResultSetMetaData methods getColumnCount and
getColumnLabel in an example where the column names and column count are unknown.

Listing 10-9: Using ResultSetMetaData

public void printResultSet(String query){