com.rapidminer.tools.jdbc
Class DatabaseHandler

java.lang.Object
  com.rapidminer.tools.jdbc.DatabaseHandler

public class DatabaseHandler
extends java.lang.Object

This class hides the database. Using connect(String,String,boolean), you can extablish a connection to the database. Once connected, queries and updates are possible.

Please note that the queries does not end with the statement terminator (e.g. ; for Oracle or GO for Sybase). The JDBC driver will automatically add the correct terminator.

Author:

Ingo Mierswa

Field Summary

static int	OVERWRITE_MODE_APPEND
static int	OVERWRITE_MODE_NONE
static int	OVERWRITE_MODE_OVERWRITE
static int	OVERWRITE_MODE_OVERWRITE_FIRST
static java.lang.String[]	OVERWRITE_MODES

Constructor Summary

DatabaseHandler(java.lang.String databaseURL, JDBCProperties properties)
Constructor of the database handler.

Method Summary

void	addColumn(Attribute attribute, java.lang.String tableName) Adds a column for the given attribute to the table with name tableName.
void	commit() Makes all changes to the database permanent.
void	connect(java.lang.String username, java.lang.String passwd, boolean autoCommit) Establishes a connection to the database.
static java.util.List<Attribute>	createAttributes(java.sql.ResultSet rs) Creates a list of attributes reflecting the result set's column meta data.
java.sql.PreparedStatement	createPreparedStatement(java.lang.String sqlString, boolean scrollableAndUpdatable) Create a prepared statement where result sets will have the properties TYPE_SCROLL_SENSITIVE and CONCUR_UPDATABLE.
java.sql.Statement	createStatement(boolean scrollableAndUpdatable) Create a statement where result sets will have the properties TYPE_SCROLL_SENSITIVE and CONCUR_UPDATABLE.
void	createTable(ExampleSet exampleSet, java.lang.String tableName, int overwriteMode, boolean firstAttempt, int defaultVarcharLength) Creates a new table in this connection and fills it with the provided data.
void	disconnect() Closes the connection to the database.
java.util.Map<java.lang.String,java.util.List<ColumnIdentifier>>	getAllTableMetaData()
static DatabaseHandler	getConnectedDatabaseHandler(java.lang.String databaseURL, java.lang.String username, java.lang.String password, JDBCProperties properties, LoggingHandler logging) Returns a connected database handler instance from the given connection data.
java.sql.Connection	getConnection() Returns the connection.
static java.lang.String	getDatabaseName(Attribute attribute) Deprecated. Use the open and close quotes for identifiers from the properties instead
JDBCProperties	getProperties() Returns the JDBC properties associated with this handler.
static int	getRapidMinerTypeIndex(int sqlType) Returns for the given SQL-type the name of the corresponding RapidMiner-Type from com.rapidminer.tools.Ontology.
java.sql.ResultSet	query(java.lang.String sqlQuery) Deprecated. Use the method createStatement(boolean) instead and perform the queries explicitely since this method would not allow closing the statement
void	removeColumn(Attribute attribute, java.lang.String tableName) Removes the column of the given attribute from the table with name tableName.

Methods inherited from class java.lang.Object

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

Field Detail

OVERWRITE_MODES

public static final java.lang.String[] OVERWRITE_MODES

OVERWRITE_MODE_NONE

public static final int OVERWRITE_MODE_NONE

See Also:

Constant Field Values

OVERWRITE_MODE_OVERWRITE_FIRST

public static final int OVERWRITE_MODE_OVERWRITE_FIRST

See Also:

Constant Field Values

OVERWRITE_MODE_OVERWRITE

public static final int OVERWRITE_MODE_OVERWRITE

See Also:

Constant Field Values

OVERWRITE_MODE_APPEND

public static final int OVERWRITE_MODE_APPEND

See Also:

Constant Field Values

Constructor Detail

DatabaseHandler

public DatabaseHandler(java.lang.String databaseURL,
                       JDBCProperties properties)

Constructor of the database handler. This constructor expects the URL definition of the database which is needed by the System DriverManager to create an appropriate driver. Please note that this database handler still must be connected via invoking the method connect(String, String, boolean). If you want to directly use a connected database handler you might use the static method getConnectedDatabaseHandler(String, String, String, JDBCProperties, LoggingHandler) instead.

Method Detail

getConnectedDatabaseHandler

public static DatabaseHandler getConnectedDatabaseHandler(java.lang.String databaseURL,
                                                          java.lang.String username,
                                                          java.lang.String password,
                                                          JDBCProperties properties,
                                                          LoggingHandler logging)
                                                   throws OperatorException,
                                                          java.sql.SQLException

Returns a connected database handler instance from the given connection data. If the password is null, it will be queries by the user during this method.

Throws:

OperatorException

java.sql.SQLException

getProperties

public JDBCProperties getProperties()

Returns the JDBC properties associated with this handler.

connect

public void connect(java.lang.String username,
                    java.lang.String passwd,
                    boolean autoCommit)
             throws java.sql.SQLException

Establishes a connection to the database. Afterwards, queries and updates can be executed using the methods this class provides.

Parameters:

username - Name with which to log in to the database. Might be null.

passwd - Password with which to log in to the database. Might be null.

autoCommit - If TRUE, all changes to the database will be committed automatically. If FALSE, the commit()-Method has to be called to make changes permanent.

Throws:

java.sql.SQLException

disconnect

public void disconnect()
                throws java.sql.SQLException

Closes the connection to the database.

Throws:

java.sql.SQLException

getConnection

public java.sql.Connection getConnection()

Returns the connection. Might be used in order to create statements. The return value might be null if this database handler is not connected.

createStatement

public java.sql.Statement createStatement(boolean scrollableAndUpdatable)
                                   throws java.sql.SQLException

Create a statement where result sets will have the properties TYPE_SCROLL_SENSITIVE and CONCUR_UPDATABLE. This means that the ResultSet is scrollable and also updatable. It will also directly show all changes to the database made by others after this ResultSet was obtained. Will throw an SQLException if the handler is not connected.

Throws:

java.sql.SQLException

createPreparedStatement

public java.sql.PreparedStatement createPreparedStatement(java.lang.String sqlString,
                                                          boolean scrollableAndUpdatable)
                                                   throws java.sql.SQLException

Create a prepared statement where result sets will have the properties TYPE_SCROLL_SENSITIVE and CONCUR_UPDATABLE. This means that the ResultSet is scrollable and also updatable. It will also directly show all changes to the database made by others after this ResultSet was obtained. Will throw an SQLException if the handler is not connected.

Throws:

java.sql.SQLException

commit

public void commit()
            throws java.sql.SQLException

Makes all changes to the database permanent. Invoking this method explicit is usually not necessary if the connection was created with AUTO_COMMIT set to true.

Throws:

java.sql.SQLException

query

@Deprecated
public java.sql.ResultSet query(java.lang.String sqlQuery)
                         throws java.sql.SQLException

Deprecated. Use the method createStatement(boolean) instead and perform the queries explicitely since this method would not allow closing the statement

Executes the given SQL-Query. Only SQL-statements starting with "SELECT" (disregarding case) will be accepted. Any errors will result in an SQL-Exception being thrown.

Parameters:

sqlQuery - An SQL-String.

Returns:

A ResultSet-Object with the results of the query. The ResultSet is scrollable, but not updatable. It will not show changes to the database made by others after this ResultSet was obtained.

Throws:

java.sql.SQLException

addColumn

public void addColumn(Attribute attribute,
                      java.lang.String tableName)
               throws java.sql.SQLException

Adds a column for the given attribute to the table with name tableName.

Throws:

java.sql.SQLException

removeColumn

public void removeColumn(Attribute attribute,
                         java.lang.String tableName)
                  throws java.sql.SQLException

Removes the column of the given attribute from the table with name tableName.

Throws:

java.sql.SQLException

createTable

public void createTable(ExampleSet exampleSet,
                        java.lang.String tableName,
                        int overwriteMode,
                        boolean firstAttempt,
                        int defaultVarcharLength)
                 throws java.sql.SQLException

Creates a new table in this connection and fills it with the provided data.

Throws:

java.sql.SQLException - if the table should be overwritten but a table with this name already exists

getRapidMinerTypeIndex

public static int getRapidMinerTypeIndex(int sqlType)

Returns for the given SQL-type the name of the corresponding RapidMiner-Type from com.rapidminer.tools.Ontology.

createAttributes

public static java.util.List<Attribute> createAttributes(java.sql.ResultSet rs)
                                                  throws java.sql.SQLException

Creates a list of attributes reflecting the result set's column meta data.

Throws:

java.sql.SQLException

getDatabaseName

@Deprecated
public static java.lang.String getDatabaseName(Attribute attribute)

Deprecated. Use the open and close quotes for identifiers from the properties instead

getAllTableMetaData

public java.util.Map<java.lang.String,java.util.List<ColumnIdentifier>> getAllTableMetaData()
                                                                                     throws java.sql.SQLException

Throws:

java.sql.SQLException