Class JDBCCategoryDataset

  • All Implemented Interfaces:
    java.io.ObjectInputValidation, java.io.Serializable, java.lang.Cloneable, PublicCloneable, CategoryDataset, Dataset, KeyedValues2D, Values2D

    public class JDBCCategoryDataset
    extends DefaultCategoryDataset
    A CategoryDataset implementation over a database JDBC result set. The dataset is populated via a call to executeQuery(String) with the string SQL query. The SQL query must return at least two columns. The first column will be the category name and remaining columns values (each column represents a series). Subsequent calls to executeQuery(String) will refresh the dataset.

    The database connection is read-only and no write back facility exists.

    NOTE: Many people have found this class too restrictive in general use. For the greatest flexibility, please consider writing your own code to read data from aResultSet and populate a DefaultCategoryDataset directly.

    See Also:
    Serialized Form
    • Field Detail

      • serialVersionUID

        static final long serialVersionUID
        For serialization.
        See Also:
        Constant Field Values
      • connection

        private transient java.sql.Connection connection
        The database connection.
      • transpose

        private boolean transpose
        A flag the controls whether or not the table is transposed. The default is 'true' because this provides the behaviour described in the documentation.
    • Constructor Detail

      • JDBCCategoryDataset

        public JDBCCategoryDataset​(java.lang.String url,
                                   java.lang.String driverName,
                                   java.lang.String user,
                                   java.lang.String passwd)
                            throws java.lang.ClassNotFoundException,
                                   java.sql.SQLException
        Creates a new dataset with a database connection.
        Parameters:
        url - the URL of the database connection.
        driverName - the database driver class name.
        user - the database user.
        passwd - the database user's password.
        Throws:
        java.lang.ClassNotFoundException - if the driver cannot be found.
        java.sql.SQLException - if there is an error obtaining a connection to the database.
      • JDBCCategoryDataset

        public JDBCCategoryDataset​(java.sql.Connection connection)
        Create a new dataset with the given database connection.
        Parameters:
        connection - the database connection.
      • JDBCCategoryDataset

        public JDBCCategoryDataset​(java.sql.Connection connection,
                                   java.lang.String query)
                            throws java.sql.SQLException
        Creates a new dataset with the given database connection, and executes the supplied query to populate the dataset.
        Parameters:
        connection - the connection.
        query - the query.
        Throws:
        java.sql.SQLException - if there is a problem executing the query.
    • Method Detail

      • getTranspose

        public boolean getTranspose()
        Returns a flag that controls whether or not the table values are transposed when added to the dataset.
        Returns:
        A boolean.
      • setTranspose

        public void setTranspose​(boolean transpose)
        Sets a flag that controls whether or not the table values are transposed when added to the dataset.
        Parameters:
        transpose - the flag.
      • executeQuery

        public void executeQuery​(java.lang.String query)
                          throws java.sql.SQLException
        Populates the dataset by executing the supplied query against the existing database connection. If no connection exists then no action is taken.

        The results from the query are extracted and cached locally, thus applying an upper limit on how many rows can be retrieved successfully.

        Parameters:
        query - the query.
        Throws:
        java.sql.SQLException - if there is a problem executing the query.
      • executeQuery

        public void executeQuery​(java.sql.Connection con,
                                 java.lang.String query)
                          throws java.sql.SQLException
        Populates the dataset by executing the supplied query against the existing database connection. If no connection exists then no action is taken.

        The results from the query are extracted and cached locally, thus applying an upper limit on how many rows can be retrieved successfully.

        Parameters:
        con - the connection.
        query - the query.
        Throws:
        java.sql.SQLException - if there is a problem executing the query.