Package org.geotools.data.h2

Class H2DialectBasic

  • public class H2DialectBasic
extends BasicSQLDialect
    H2 database dialect based on basic (non-prepared) statements.
    Author:
    Justin Deoliveira, OpenGEO

    • Constructor Detail

      • H2DialectBasic

        public H2DialectBasic​(JDBCDataStore dataStore)

    • Method Detail

      • initializeConnection

        public void initializeConnection​(Connection cx)
                          throws SQLException
        Description copied from class: SQLDialect
        Initializes a newly created database connection.

        Subclasses should override this method if there is some additional action that needs to be taken when a new connection to the database is created. The default implementation does nothing.

        Overrides:
        initializeConnection in class SQLDialect
        Parameters:
        cx - The new database connection.
        Throws:
        SQLException

      • includeTable

        public boolean includeTable​(String schemaName,
                            String tableName,
                            Connection cx)
                     throws SQLException
        Description copied from class: SQLDialect
        Determines if the specified table should be included in those published by the datastore.

        This method returns true if the table should be published as a feature type, otherwise it returns false. Subclasses should override this method, this default implementation returns true.

        A database connection is provided to the dialect but it should not be closed. However any statements objects or result sets that are instantiated from it must be closed.

        Overrides:
        includeTable in class SQLDialect
        Parameters:
        schemaName - The schema of the table, might be null..
        tableName - The name of the table.
        cx - Database connection.
        Throws:
        SQLException

      • getNameEscape

        public String getNameEscape()
        Description copied from class: SQLDialect
        Returns the string used to escape names.

        This value is used to escape any name in a query. This includes columns, tables, schemas, indexes, etc... If no escape is necessary this method should return the empty string, and never return null.

        This default implementation returns a single double quote ("), subclasses must override to provide a different espcape.

        Overrides:
        getNameEscape in class SQLDialect

      • registerSqlTypeToClassMappings

        public void registerSqlTypeToClassMappings​(Map<Integer,​Class<?>> mappings)
        Description copied from class: SQLDialect
        Registers the sql type to java type mappings that the dialect uses when reading and writing objects to and from the database.

        Subclasses should extend (not override) this method to provide additional mappings, or to override mappings provided by this implementation. This implementation provides the following mappings:

        Overrides:
        registerSqlTypeToClassMappings in class SQLDialect

      • registerClassToSqlMappings

        public void registerClassToSqlMappings​(Map<Class<?>,​Integer> mappings)
        Description copied from class: SQLDialect
        Registers the java type to sql type mappings that the datastore uses when reading and writing objects to and from the database. *

        Subclasses should extend (not override) this method to provide additional mappings, or to override mappings provided by this implementation. This implementation provides the following mappings:

        Overrides:
        registerClassToSqlMappings in class SQLDialect

      • encodePostColumnCreateTable

        public void encodePostColumnCreateTable​(AttributeDescriptor att,
                                        StringBuffer sql)
        Description copied from class: SQLDialect
        Encodes anything post a column in a CREATE TABLE statement.

        This is appended after the column name and type. Subclasses may choose to override this method, the default implementation does nothing.

        Overrides:
        encodePostColumnCreateTable in class SQLDialect
        Parameters:
        att - The attribute corresponding to the column.

      • encodePostCreateTable

        public void encodePostCreateTable​(String tableName,
                                  StringBuffer sql)
        Description copied from class: SQLDialect
        Encodes anything post a CREATE TABLE statement.

        This is appended to a CREATE TABLE statement after the column definitions. This default implementation does nothing, subclasses should override as need be.

        Overrides:
        encodePostCreateTable in class SQLDialect

      • postCreateTable

        public void postCreateTable​(String schemaName,
                            SimpleFeatureType featureType,
                            Connection cx)
                     throws SQLException
        Description copied from class: SQLDialect
        Callback to execute any additional sql statements post a create table statement.

        This method should be implemented by subclasses that need to do some post processing on the database after a table has been created. Examples might include:

        • Creating a sequence for a primary key
        • Registering geometry column metadata
        • Creating a spatial index

        A common case is creating an auto incrementing sequence for the primary key of a table. It should be noted that all tables created through the datastore use the column "fid" as the primary key.

        A direct connection to the database is provided (cx). This connection must not be closed, however any statements or result sets instantiated from the connection must be closed.

        Overrides:
        postCreateTable in class SQLDialect
        Parameters:
        schemaName - The name of the schema, may be null.
        featureType - The feature type that has just been created on the database.
        cx - Database connection.
        Throws:
        SQLException

      • postCreateFeatureType

        public void postCreateFeatureType​(SimpleFeatureType featureType,
                                  DatabaseMetaData metadata,
                                  String schemaName,
                                  Connection cx)
                           throws SQLException
        Description copied from class: SQLDialect
        Callback which executes after a feature type has been built from a database table.

        This base implementation does nothing, subclasses should override as need be.

        Overrides:
        postCreateFeatureType in class SQLDialect
        Parameters:
        featureType - The build feature type.
        metadata - The database metadata.
        schemaName - The name of the database scheam containing the table containing the column
        cx - The database connection.
        Throws:
        SQLException

      • preDropTable

        public void preDropTable​(String schemaName,
                         SimpleFeatureType featureType,
                         Connection cx)
                  throws SQLException
        Description copied from class: SQLDialect
        Callback which executes before a table is about to be dropped.

        This base implementation does nothing, subclasses should override as need be.

        Overrides:
        preDropTable in class SQLDialect
        Parameters:
        schemaName - The database schema containing the table.
        featureType - The featureType/table being dropped.
        cx - The database connection.
        Throws:
        SQLException

      • postDropTable

        public void postDropTable​(String schemaName,
                          SimpleFeatureType featureType,
                          Connection cx)
                   throws SQLException
        Description copied from class: SQLDialect
        Callback which executes after a table has been dropped.

        This base implementation does nothing, subclasses should override as need be.

        Overrides:
        postDropTable in class SQLDialect
        Parameters:
        schemaName - The database schema containing the table.
        featureType - The featureType/table being dropped.
        cx - The database connection.
        Throws:
        SQLException

      • getGeometrySRID

        public Integer getGeometrySRID​(String schemaName,
                               String tableName,
                               String columnName,
                               Connection cx)
                        throws SQLException
        Description copied from class: SQLDialect
        Returns the spatial reference system identifier (srid) for a particular geometry column.

        This method is given a direct connection to the database. The connection must not be closed. However any statements or result sets instantiated from the connection must be closed.

        In the event that the srid cannot be determined, this method should return null .

        Overrides:
        getGeometrySRID in class SQLDialect
        Parameters:
        schemaName - The database schema, could be null.
        tableName - The table, never null.
        columnName - The column name, never null
        cx - The database connection.
        Throws:
        SQLException

      • encodePrimaryKey

        public void encodePrimaryKey​(String column,
                             StringBuffer sql)
        Description copied from class: SQLDialect
        Encodes the primary key definition in a CREATE TABLE statement.

        Subclasses should override this method if need be, the default implementation does the following: 

           
   encodeColumnName( column, sql );
   sql.append( " int PRIMARY KEY" );
        Overrides:
        encodePrimaryKey in class SQLDialect

      • getSequenceForColumn

        public String getSequenceForColumn​(String schemaName,
                                   String tableName,
                                   String columnName,
                                   Connection cx)
                            throws SQLException
        Description copied from class: SQLDialect
        Determines the name of the sequence (if any) which is used to increment generate values for a table column.

        This method should return null if no such sequence exists.

        This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

        Overrides:
        getSequenceForColumn in class SQLDialect
        Parameters:
        schemaName - The schema name, this might be null.
        tableName - The table name.
        columnName - The column name.
        cx - The database connection.
        Throws:
        SQLException

      • getNextSequenceValue

        public Object getNextSequenceValue​(String schemaName,
                                   String sequenceName,
                                   Connection cx)
                            throws SQLException
        Description copied from class: SQLDialect
        Obtains the next value of a sequence, incrementing the sequence to the next state in the process.

        Implementations should determine the next value of a column for which values are automatically generated by the database.

        This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

        Implementations should handle the case where schemaName is null.

        Overrides:
        getNextSequenceValue in class SQLDialect
        Parameters:
        schemaName - The schema name, this might be null.
        sequenceName - The name of the sequence.
        cx - The database connection.
        Returns:
        The next value of the sequence, or null.
        Throws:
        SQLException

      • encodeNextSequenceValue

        public String encodeNextSequenceValue​(String schemaName,
                                      String sequenceName)
        Description copied from class: SQLDialect
        Encodes how to get the next sequence value from the DB.

        Implementations should handle the case where schemaName is null.

        Overrides:
        encodeNextSequenceValue in class SQLDialect

      • getNextAutoGeneratedValue

        public Object getNextAutoGeneratedValue​(String schemaName,
                                        String tableName,
                                        String columnName,
                                        Connection cx)
                                 throws SQLException
        Description copied from class: SQLDialect
        Obtains the next value of an auto generated column.

        Implementations should determine the next value of a column for which values are automatically generated by the database.

        This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

        Implementations should handle the case where schemaName is null.

        Overrides:
        getNextAutoGeneratedValue in class SQLDialect
        Parameters:
        schemaName - The schema name, this might be null.
        tableName - The name of the table.
        columnName - The column.
        cx - The database connection.
        Returns:
        The next value of the column, or null.
        Throws:
        SQLException

      • getLastAutoGeneratedValue

        public Object getLastAutoGeneratedValue​(String schemaName,
                                        String tableName,
                                        String columnName,
                                        Connection cx)
                                 throws SQLException
        Description copied from class: SQLDialect
        Obtains the last value of an auto generated column.

        This method is only called when SQLDialect.lookupGeneratedValuesPostInsert() returns true. Implementations should determine the previous value of a column for which was automatically generated by the database.

        This method is given a direct connection to the database, but this connection should never be closed. However any statements or result sets instantiated from the connection must be closed.

        Implementations should handle the case where schemaName is null.

        Overrides:
        getLastAutoGeneratedValue in class SQLDialect
        Parameters:
        schemaName - The schema name, this might be null.
        tableName - The name of the table.
        columnName - The column.
        cx - The database connection.
        Returns:
        The previous value of the column, or null.
        Throws:
        SQLException

      • encodeGeometryEnvelope

        public void encodeGeometryEnvelope​(String tableName,
                                   String geometryColumn,
                                   StringBuffer sql)
        Description copied from class: SQLDialect
        Encodes the spatial extent function of a geometry column in a SELECT statement.

        This method must also be sure to properly encode the name of the column with the #encodeColumnName(String, StringBuffer) function.

        Specified by:
        encodeGeometryEnvelope in class SQLDialect

      • encodeValue

        public void encodeValue​(Object value,
                        Class type,
                        StringBuffer sql)
        Description copied from class: BasicSQLDialect
        Encodes a value in an sql statement.

        Subclasses may wish to override or extend this method to handle specific types. This default implementation does the following:

        1. The value is encoded via its Object.toString() representation.
        2. If type is a character type (extends CharSequence), it is wrapped in single quotes (').
        Overrides:
        encodeValue in class BasicSQLDialect

      • encodeGeometryValue

        public void encodeGeometryValue​(Geometry value,
                                int dimension,
                                int srid,
                                StringBuffer sql)
                         throws IOException
        Description copied from class: BasicSQLDialect
        Encodes a geometry value in an sql statement.

        An implementations should serialize value into some exchange format which will then be transported to the underlying database. For example, consider an implementation which converts a geometry into its well known text representation: 

           
   sql.append( "GeomFromText('" );
   sql.append( new WKTWriter().write( value ) );
   sql.append( ")" );

        The srid parameter is the spatial reference system identifier of the geometry, or 0 if not known.

        Attention should be paid to emtpy geometries (g.isEmtpy() == true) as they cannot be encoded in WKB and several databases fail to handle them property. Common treatment is to equate them to NULL

        Specified by:
        encodeGeometryValue in class BasicSQLDialect
        Throws:
        IOException

      • decodeGeometryValue

        public Geometry decodeGeometryValue​(GeometryDescriptor descriptor,
                                    ResultSet rs,
                                    String column,
                                    GeometryFactory factory,
                                    Connection cx,
                                    Hints hints)
                             throws IOException,
                                    SQLException
        Description copied from class: SQLDialect
        Decodes a geometry value from the result of a query.

        This method is given direct access to a result set. The column parameter is the index into the result set which contains the geometric value.

        An implementation should deserialize the value provided by the result set into Geometry object. For example, consider an implementation which deserializes from well known text: 

           String wkt = rs.getString( column );
   if ( wkt == null ) {
     return null;
   }
   return new WKTReader(factory).read( wkt );
        Note that implementations must handle null values.

        The factory parameter should be used to instantiate any geometry objects.

        Specified by:
        decodeGeometryValue in class SQLDialect
        Throws:
        IOException
        SQLException

      • applyLimitOffset

        public void applyLimitOffset​(StringBuffer sql,
                             int limit,
                             int offset)
        Description copied from class: SQLDialect
        Alters the query provided so that limit and offset are natively dealt with. This might mean simply appending some extra directive to the query, or wrapping it into a bigger one.
        Overrides:
        applyLimitOffset in class SQLDialect

      • supportsSchemaForIndex

        protected boolean supportsSchemaForIndex()
        Description copied from class: SQLDialect
        Return true if the database supports individual schemas for indices.

        The SQL encoding would be CREATE INDEX SCHEMANAME.INDEXNAME ON ....

        The default is false and the encoding is CREATE INDEX INDEXNAME ON ....

        Overrides:
        supportsSchemaForIndex in class SQLDialect
        Returns:
        true or false

      • registerSqlTypeToSqlTypeNameOverrides

        public void registerSqlTypeToSqlTypeNameOverrides​(Map<Integer,​String> overrides)
        Description copied from class: SQLDialect
        Registers any overrides that should occur when mapping an integer sql type value to an underlying sql type name.

        The default implementation of this method does nothing. Subclasses should override in cases where:

        • database type metadata does not provide enough information to properly map
        • to support custom types (those not in Types)
        Overrides:
        registerSqlTypeToSqlTypeNameOverrides in class SQLDialect