Package org.geotools.data.informix

Class InformixDialect

  • public class InformixDialect
extends BasicSQLDialect
    Informix database dialect based on basic (non-prepared) statements.
    Author:
    George Dewar, Land Information New Zealand, Ines Falcao, Land Information New Zealand

    • Constructor Detail

      • InformixDialect

        public InformixDialect​(JDBCDataStore dataStore)

    • Method Detail

      • 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

      • 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

      • encodeGeometryColumn

        public void encodeGeometryColumn​(GeometryDescriptor gatt,
                                 String prefix,
                                 int srid,
                                 Hints hints,
                                 StringBuffer sql)
        Description copied from class: SQLDialect
        Encodes the name of a geometry column in a SELECT statement.

        This method should wrap the column name in any functions that are used to retrieve its value. For instance, often it is necessary to use the function asText, or asWKB when fetching a geometry.

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

        Example: 

           
   sql.append( "asText(" );
   column( gatt.getLocalName(), sql );
   sql.append( ")" );
        Overrides:
        encodeGeometryColumn in class SQLDialect

      • 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

      • encodeGeometryValue

        public void encodeGeometryValue​(Geometry value,
                                int dimension,
                                int srid,
                                StringBuffer sql)
        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

      • 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

      • 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

      • registerSqlTypeNameToClassMappings

        public void registerSqlTypeNameToClassMappings​(Map<String,​Class<?>> mappings)
        Description copied from class: SQLDialect
        Registers the sql type name 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:
        registerSqlTypeNameToClassMappings 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.

      • postCreateTable

        public void postCreateTable​(String schemaName,
                            SimpleFeatureType featureType,
                            Connection cx)
                     throws SQLException,
                            IOException
        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
        IOException

      • 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

      • 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

      • 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

      • getOptimizedBounds

        public List<ReferencedEnvelope> getOptimizedBounds​(String schema,
                                                   SimpleFeatureType featureType,
                                                   Connection cx)
                                            throws IOException
        Description copied from class: SQLDialect
        Returns the bounds of all geometry columns in the layer using any approach that proves to be faster than the plain bounds aggregation (e.g., better than the "plain select extent(geom) from table" on PostGIS), or null if none exists or the fast method has not been enabled (e.g., if the fast method is just an estimate of the bounds you probably want the user to enable it manually)
        Overrides:
        getOptimizedBounds in class SQLDialect
        Parameters:
        schema - The database schema, if any, or null
        featureType - The feature type containing the geometry columns whose bounds need to computed. Mind, it may be retyped and thus contain less geometry columns than the table
        Returns:
        a list of referenced envelopes (some of which may be null or empty)
        Throws:
        IOException