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.
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HSQLDB-Specific Information:
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)
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jdbcResultSet.FETCH_FORWARD
jdbcResultSet.TYPE_FORWARD_ONLY
jdbcResultSet TYPE_SCROLL_INSENSITIVE
jdbcResultSet.CONCUR_READ_ONLY
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.
url
- the URL of the database
- true if this driver can connect to the given URL
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.
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HSQLDB-Specific Information:
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.
<!-- end release-specific documentation -->
url
- the URL of the database to which to connectinfo
- a list of arbitrary string tag/value pairs as connection
arguments. Normally at least a "user" and "password" property
should be included.
- a
Connection
object that represents a
connection to the URL
getConnection
public static Connection getConnection(String url,
Properties info)
throws SQLException
getMajorVersion
public int getMajorVersion()
Gets the driver's major version number.
- this driver's major version number
getMinorVersion
public int getMinorVersion()
Gets the driver's minor version number.
- this driver's minor version number
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.
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HSQLDB-Specific Information:
HSQLDB 1.7.2 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.
<!-- end release-specific documentation -->
url
- the URL of the database to which to connectinfo
- a proposed list of tag/value pairs that will be sent on
connect open
- an array of DriverPropertyInfo objects describing possible
properties. This array may be an empty array if no properties
are required.
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.
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HSQLDB-Specific Information:
HSQL Database Engine currently does not yet
support all required SQL 92 Entry Level functionality and thus
returns false. It looks like other drivers return true but do not
support all features.
<!-- end release-specific documentation -->
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.
- Description of the Return Value