org.geotools.jdbc

Class BasicSQLDialect

Object

SQLDialect

BasicSQLDialect

Direct Known Subclasses:

DB2SQLDialectBasic, H2DialectBasic, MySQLDialectBasic, PostGISDialect, SQLServerDialect

public abstract class BasicSQLDialect
extends SQLDialect

Field Summary

Fields inherited from class SQLDialect

BASE_DBMS_CAPABILITIES, dataStore, LOGGER

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BasicSQLDialect(JDBCDataStore dataStore)

Method Summary

Modifier and Type	Method and Description
FilterToSQL	createFilterToSQL() Creates the filter encoder to be used by the datastore when encoding query predicates.
abstract void	encodeGeometryValue(Geometry value, int dimension, int srid, StringBuffer sql) Encodes a geometry value in an sql statement.
void	encodeValue(Object value, Class type, StringBuffer sql) Encodes a value in an sql statement.
void	onDelete(Statement delete, Connection cx, SimpleFeatureType featureType) Callback invoked before a DELETE statement is executed against the database.
void	onInsert(Statement insert, Connection cx, SimpleFeatureType featureType) Callback invoked before an INSERT statement is executed against the database.
void	onSelect(Statement select, Connection cx, SimpleFeatureType featureType) Callback invoked before a SELECT statement is executed against the database.
void	onUpdate(Statement update, Connection cx, SimpleFeatureType featureType) Callback invoked before an UPDATE statement is executed against the database.

Methods inherited from class SQLDialect

addSupportedHints, applyLimitOffset, canGroupOnGeometry, canSimplifyPoints, convertValue, createCRS, createIndex, decodeGeometryEnvelope, decodeGeometryValue, decodeGeometryValue, dropIndex, encodeColumnAlias, encodeColumnName, encodeColumnType, encodeCreateTable, encodeGeometryColumn, encodeGeometryColumnGeneralized, encodeGeometryColumnSimplified, encodeGeometryEnvelope, encodeJoin, encodeNextSequenceValue, encodePostColumnCreateTable, encodePostCreateTable, encodePostSelect, encodePrimaryKey, encodeSchemaName, encodeTableAlias, encodeTableName, escapeName, getAggregateConverter, getDefaultVarcharSize, getDesiredTablesType, getGeometryDimension, getGeometrySRID, getGeometryTypeName, getIndexes, getLastAutoGeneratedValue, getLastAutoGeneratedValue, getMapping, getNameEscape, getNextAutoGeneratedValue, getNextSequenceValue, getOptimizedBounds, getPkColumnValue, getPrimaryKey, getRestrictions, getResultTypes, getSequenceForColumn, getSQLType, handleSelectHints, handleUserDefinedType, includeTable, initializeConnection, isAggregatedSortSupported, isArray, isAutoCommitQuery, isGroupBySupported, isLimitOffsetSupported, lookupGeneratedValuesPostInsert, ne, postCreateAttribute, postCreateFeatureType, postCreateTable, postDropTable, preDropTable, registerAggregateFunctions, registerClassToSqlMappings, registerSqlTypeNameToClassMappings, registerSqlTypeToClassMappings, registerSqlTypeToSqlTypeNameOverrides, splitFilter, supportsSchemaForIndex

Methods inherited from class Object

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

Constructor Detail

BasicSQLDialect

protected BasicSQLDialect(JDBCDataStore dataStore)

Method Detail

encodeValue

public void encodeValue(Object value,
                        Class type,
                        StringBuffer sql)

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 (').

encodeGeometryValue

public abstract void encodeGeometryValue(Geometry value,
                                         int dimension,
                                         int srid,
                                         StringBuffer sql)
                                  throws IOException

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

Throws:

IOException

createFilterToSQL

public FilterToSQL createFilterToSQL()

Creates the filter encoder to be used by the datastore when encoding query predicates.

Sublcasses can override this method to return a subclass of FilterToSQL if need be.

onSelect

public void onSelect(Statement select,
                     Connection cx,
                     SimpleFeatureType featureType)
              throws SQLException

Callback invoked before a SELECT statement is executed against the database.

The callback is provided with both the statement being executed and the database connection. Neither should be closed. Any statements created from the connection however in this method should be closed.

Parameters:

select - The select statement being executed

cx - The database connection

featureType - The feature type the select is executing against.

Throws:

SQLException

onDelete

public void onDelete(Statement delete,
                     Connection cx,
                     SimpleFeatureType featureType)
              throws SQLException

Callback invoked before a DELETE statement is executed against the database.

The callback is provided with both the statement being executed and the database connection. Neither should be closed. Any statements created from the connection however in this method should be closed.

Parameters:

delete - The delete statement being executed

cx - The database connection

featureType - The feature type the delete is executing against.

Throws:

SQLException

onInsert

public void onInsert(Statement insert,
                     Connection cx,
                     SimpleFeatureType featureType)
              throws SQLException

Callback invoked before an INSERT statement is executed against the database.

The callback is provided with both the statement being executed and the database connection. Neither should be closed. Any statements created from the connection however in this method should be closed.

Parameters:

insert - The delete statement being executed

cx - The database connection

featureType - The feature type the insert is executing against.

Throws:

SQLException

onUpdate

public void onUpdate(Statement update,
                     Connection cx,
                     SimpleFeatureType featureType)
              throws SQLException

Callback invoked before an UPDATE statement is executed against the database.

The callback is provided with both the statement being executed and the database connection. Neither should be closed. Any statements created from the connection however in this method should be closed.

Parameters:

update - The delete statement being executed

cx - The database connection

featureType - The feature type the update is executing against.

Throws:

SQLException