prefuse.data.io.sql
Class DatabaseDataSource

java.lang.Object
  prefuse.data.io.sql.DatabaseDataSource

public class DatabaseDataSource
extends java.lang.Object

Sends queries to a relational database and processes the results, storing the results in prefuse Table instances. This class should not be instantiated directly. To access a database, the ConnectionFactory class should be used to retrieve an appropriate instance of this class.

Author:

jeffrey heer

Field Summary

protected java.sql.Connection	m_conn
protected SQLDataHandler	m_handler
protected java.sql.Statement	m_stmt

Method Summary

Table	getData(java.lang.String query) Executes a query and returns the results in a Table instance.
Table	getData(java.lang.String query, java.lang.String keyField) Executes a query and returns the results in a Table instance.
Table	getData(Table t, java.lang.String query) Executes a query and returns the results in a Table instance.
Table	getData(Table t, java.lang.String query, java.lang.String keyField) Executes a query and returns the results in a Table instance.
Table	getData(Table t, java.lang.String query, java.lang.String keyField, java.lang.Object lock) Executes a query and returns the results in a Table instance.
protected int	getExistingRow(Table t, java.sql.ResultSet rset, java.lang.String keyField) See if a retrieved database row is already represented in the given Table.
Schema	getSchema(java.sql.ResultSetMetaData metadata, SQLDataHandler handler) Given the metadata for a SQL result set and a data value handler for that result set, returns a corresponding schema for a prefuse table.
void	loadData(Table t, java.lang.String query) Asynchronously executes a query and stores the results in the given table instance.
void	loadData(Table t, java.lang.String query, java.lang.Object lock) Asynchronously executes a query and stores the results in the given table instance.
void	loadData(Table t, java.lang.String query, java.lang.String keyField) Asynchronously executes a query and stores the results in the given table instance.
void	loadData(Table t, java.lang.String query, java.lang.String keyField, java.lang.Object lock) Asynchronously executes a query and stores the results in the given table instance.
void	loadData(Table t, java.lang.String query, java.lang.String keyField, java.lang.Object lock, DataSourceWorker.Listener listener) Asynchronously executes a query and stores the results in the given table instance.
protected Table	process(Table t, java.sql.ResultSet rset, java.lang.String key, java.lang.Object lock) Process the results of a SQL query, putting retrieved data into a Table instance.

Methods inherited from class java.lang.Object

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

Field Detail

m_conn

protected java.sql.Connection m_conn

m_stmt

protected java.sql.Statement m_stmt

m_handler

protected SQLDataHandler m_handler

Method Detail

getData

public Table getData(java.lang.String query)
              throws DataIOException

Executes a query and returns the results in a Table instance.

Parameters:

query - the text SQL query to execute

Returns:

a Table of the query results

Throws:

DataIOException - if an error occurs while executing the query or adding the query results in a prefuse Table.

getData

public Table getData(java.lang.String query,
                     java.lang.String keyField)
              throws DataIOException

Executes a query and returns the results in a Table instance.

Parameters:

query - the text SQL query to execute

keyField - the field to treat as a primary key, ensuring that this field is indexed in the resulting table instance.

Returns:

a Table of the query results

Throws:

DataIOException - if an error occurs while executing the query or adding the query results in a prefuse Table.

getData

public Table getData(Table t,
                     java.lang.String query)
              throws DataIOException

Executes a query and returns the results in a Table instance.

Parameters:

t - the Table to store the results in. If this value is null, a new table will automatically be created.

query - the text SQL query to execute

Returns:

a Table of the query results

Throws:

DataIOException - if an error occurs while executing the query or adding the query results in a prefuse Table.

getData

public Table getData(Table t,
                     java.lang.String query,
                     java.lang.String keyField)
              throws DataIOException

Executes a query and returns the results in a Table instance.

Parameters:

t - the Table to store the results in. If this value is null, a new table will automatically be created.

query - the text SQL query to execute

keyField - used to determine if the row already exists in the table

Returns:

a Table of the query results

Throws:

DataIOException - if an error occurs while executing the query or adding the query results in a prefuse Table.

getData

public Table getData(Table t,
                     java.lang.String query,
                     java.lang.String keyField,
                     java.lang.Object lock)
              throws DataIOException

Executes a query and returns the results in a Table instance.

Parameters:

t - the Table to store the results in. If this value is null, a new table will automatically be created.

query - the text SQL query to execute

keyField - used to determine if the row already exists in the table

lock - an optional Object to use as a lock when performing data processing. This lock will be synchronized on whenever the Table is modified.

Returns:

a Table of the query results

Throws:

DataIOException - if an error occurs while executing the query or adding the query results in a prefuse Table.

loadData

public void loadData(Table t,
                     java.lang.String query)

Asynchronously executes a query and stores the results in the given table instance. All data processing is done in a separate thread of execution.

Parameters:

t - the Table in which to store the results

query - the query to execute

loadData

public void loadData(Table t,
                     java.lang.String query,
                     java.lang.String keyField)

Asynchronously executes a query and stores the results in the given table instance. All data processing is done in a separate thread of execution.

Parameters:

t - the Table in which to store the results

query - the query to execute

keyField - the primary key field, comparisons on this field are performed to recognize data records already present in the table.

loadData

public void loadData(Table t,
                     java.lang.String query,
                     java.lang.Object lock)

Asynchronously executes a query and stores the results in the given table instance. All data processing is done in a separate thread of execution.

Parameters:

t - the Table in which to store the results

query - the query to execute

lock - an optional Object to use as a lock when performing data processing. This lock will be synchronized on whenever the Table is modified.

loadData

public void loadData(Table t,
                     java.lang.String query,
                     java.lang.String keyField,
                     java.lang.Object lock)

Asynchronously executes a query and stores the results in the given table instance. All data processing is done in a separate thread of execution.

Parameters:

t - the Table in which to store the results

query - the query to execute

keyField - the primary key field, comparisons on this field are performed to recognize data records already present in the table.

lock - an optional Object to use as a lock when performing data processing. This lock will be synchronized on whenever the Table is modified.

loadData

public void loadData(Table t,
                     java.lang.String query,
                     java.lang.String keyField,
                     java.lang.Object lock,
                     DataSourceWorker.Listener listener)

Asynchronously executes a query and stores the results in the given table instance. All data processing is done in a separate thread of execution.

Parameters:

t - the Table in which to store the results

query - the query to execute

keyField - the primary key field, comparisons on this field are performed to recognize data records already present in the table. A null value will result in no key checking.

lock - an optional Object to use as a lock when performing data processing. This lock will be synchronized on whenever the Table is modified. A null value will result in no locking.

listener - an optional listener that will provide notifications before the query has been issued and after the query has been processed. This is most useful for post-processing operations.

process

protected Table process(Table t,
                        java.sql.ResultSet rset,
                        java.lang.String key,
                        java.lang.Object lock)
                 throws DataIOException

Process the results of a SQL query, putting retrieved data into a Table instance. If a null table is provided, a new table with the appropriate schema will be created.

Parameters:

t - the Table to store results in

rset - the SQL query result set

Returns:

a Table containing the query results

Throws:

DataIOException

getExistingRow

protected int getExistingRow(Table t,
                             java.sql.ResultSet rset,
                             java.lang.String keyField)
                      throws java.sql.SQLException

See if a retrieved database row is already represented in the given Table.

Parameters:

t - the prefuse Table to check for an existing row

rset - the ResultSet, set to a particular row, which may or may not have a matching row in the prefuse Table

keyField - the key field to look up to check for an existing row

Returns:

the index of the existing row, or -1 if no match is found

Throws:

java.sql.SQLException

getSchema

public Schema getSchema(java.sql.ResultSetMetaData metadata,
                        SQLDataHandler handler)
                 throws java.sql.SQLException

Given the metadata for a SQL result set and a data value handler for that result set, returns a corresponding schema for a prefuse table.

Parameters:

metadata - the SQL result set metadata

handler - the data value handler

Returns:

the schema determined by the metadata and handler

Throws:

java.sql.SQLException - if an error occurs accessing the metadata