org.hsqldb
Class jdbcDriver

java.lang.Object
  org.hsqldb.jdbcDriver

All Implemented Interfaces:

Driver

public class jdbcDriver

extends Object

implements Driver

Each JDBC driver must supply a class that implements the Driver interface.

The Java SQL framework allows for multiple database drivers.

The DriverManager will try to load as many drivers as it can find and then for any given connection request, it will ask each driver in turn to try to connect to the target URL.

The application developer will normally not need to call any function of the Driver directly. All required calls are made by the DriverManager.

When the HSQL Database Engine Driver class is loaded, it creates an instance of itself and register it with the DriverManager. This means that a user can load and register the HSQL Database Engine driver by calling

 Class.forName("org.hsqldb.jdbcDriver") 

For more information about how to connect to a HSQL Database Engine database, please see jdbcConnection.

As of version 1.7.0 all JDBC 2 methods can be called with jdk 1.1.x. Some of these method calls require int values that are defined in JDBC 2 version of ResultSet. These values are defined in the jdbcResultSet class when it is compiled with jdk 1.1.x. When using the JDBC 2 methods that require those values as parameters or return one of those values, refer to them as follows: (The code will not be compatible with other JDBC 2 driver, which require ResultSet to be used instead of jdbcResultSet) (fredt@users)

jdbcResultSet.FETCH_FORWARD
jdbcResultSet.TYPE_FORWARD_ONLY
jdbcResultSet TYPE_SCROLL_INSENSITIVE
jdbcResultSet.CONCUR_READ_ONLY

See Also:

jdbcConnection

Constructor Summary

jdbcDriver()

Method Summary

boolean	acceptsURL(String url) Returns true if the driver thinks that it can open a connection to the given URL.
Connection	connect(String url, Properties info) Attempts to make a database connection to the given URL.
static Connection	getConnection(String url, Properties info)
int	getMajorVersion() Gets the driver's major version number.
int	getMinorVersion() Gets the driver's minor version number.
DriverPropertyInfo[]	getPropertyInfo(String url, Properties info) Gets information about the possible properties for this driver.
boolean	jdbcCompliant() Reports whether this driver is a genuine JDBC COMPLIANTTM driver.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

jdbcDriver

public jdbcDriver()

Method Detail

connect

public Connection connect(String url,
                          Properties info)
                   throws SQLException

Attempts to make a database connection to the given URL. The driver returns "null" if it realizes it is the wrong kind of driver to connect to the given URL. This will be common, as when the JDBC driver manager is asked to connect to a given URL it passes the URL to each loaded driver in turn.

The driver raises a SQLException if it is the right driver to connect to the given URL, but has trouble connecting to the database.

The java.util.Properties argument can be used to passed arbitrary string tag/value pairs as connection arguments.

For HSQL Database Engine, at least "user" and "password" properties must be included in the Properties. From version 1.7.1 two optional properties are supported:

get_column_name if set to false, a ResultSetMetaData.getColumnName() call will return the user defined label instead of the column name. strict_md if set to true, some ResultSetMetaData methods return more strict values for compatibility reasons.

Specified by:

connect in interface Driver

Parameters:

url - the URL of the database to which to connect

info - a list of arbitrary string tag/value pairs as connection arguments. Normally at least a "user" and "password" property should be included.

Returns:

a Connection object that represents a connection to the URL

Throws:

SQLException - if a database access error occurs

getConnection

public static Connection getConnection(String url,
                                       Properties info)
                                throws SQLException

Throws:

SQLException

To Do:

error message

acceptsURL

public boolean acceptsURL(String url)

Returns true if the driver thinks that it can open a connection to the given URL. Typically drivers will return true if they understand the subprotocol specified in the URL and false if they don't.

Specified by:

acceptsURL in interface Driver

Parameters:

url - the URL of the database

Returns:

true if this driver can connect to the given URL

getPropertyInfo

public DriverPropertyInfo[] getPropertyInfo(String url,
                                            Properties info)

Gets information about the possible properties for this driver.

The getPropertyInfo method is intended to allow a generic GUI tool to discover what properties it should prompt a human for in order to get enough information to connect to a database. Note that depending on the values the human has supplied so far, additional values may become necessary, so it may be necessary to iterate though several calls to getPropertyInfo. HSQLDB-Specific Information:

HSQLDB 1.7.1 uses the values submitted in info to set the value for each DriverPropertyInfo object returned. It does not use the default value that it would use for the property if the value is null.

Specified by:

getPropertyInfo in interface Driver

Parameters:

url - the URL of the database to which to connect

info - a proposed list of tag/value pairs that will be sent on connect open

Returns:

an array of DriverPropertyInfo objects describing possible properties. This array may be an empty array if no properties are required.

getMajorVersion

public int getMajorVersion()

Gets the driver's major version number.

Specified by:

getMajorVersion in interface Driver

Returns:

this driver's major version number

getMinorVersion

public int getMinorVersion()

Gets the driver's minor version number.

Specified by:

getMinorVersion in interface Driver

Returns:

this driver's minor version number

jdbcCompliant

public boolean jdbcCompliant()

Reports whether this driver is a genuine JDBC COMPLIANT^TM driver. A driver may only report true here if it passes the JDBC compliance tests; otherwise it is required to return false. JDBC compliance requires full support for the JDBC API and full support for SQL 92 Entry Level. It is expected that JDBC compliant drivers will be available for all the major commercial databases.

HSQL Database Engine currently does not yet support all required SQL 92 Entry Level functionality and thus returns false. The features that are missing are currently 'HAVING' and views. It looks like other drivers return true but do not support all features.

This method is not intended to encourage the development of non-JDBC compliant drivers, but is a recognition of the fact that some vendors are interested in using the JDBC API and framework for lightweight databases that do not support full database functionality, or for special databases such as document information retrieval where a SQL implementation may not be feasible.

Specified by:

jdbcCompliant in interface Driver

Returns:

Description of the Return Value