org.apache.metamodel.jdbc.dialects

Class AbstractQueryRewriter

java.lang.Object

org.apache.metamodel.jdbc.dialects.AbstractQueryRewriter

All Implemented Interfaces:

IQueryRewriter

Direct Known Subclasses:

DefaultQueryRewriter

public abstract class AbstractQueryRewriter
extends Object
implements IQueryRewriter

Abstract implementation of query rewriter. This implementation delegates the rewriting of the Query into several subtasks according to the query items to be rendered. This makes it easy to overload single methods in order to correct syntax quirks.

Constructor Summary

Constructors

Constructor and Description
AbstractQueryRewriter(JdbcDataContext dataContext)

Method Summary

Modifier and Type	Method and Description
protected Query	beforeRewrite(Query query) Method to modify query before rewriting begins.
ColumnType	getColumnType(int jdbcType, String nativeType, Integer columnSize) Gets the column type for a specific JDBC type (as defined in Types), native type name and column size.
JdbcDataContext	getDataContext()
Object	getResultSetValue(ResultSet resultSet, int columnIndex, Column column) Retrieves a value from a JDBC ResultSet when the anticipated value is mapped to a particular column.
boolean	isSchemaIncludedInColumnPaths()
protected boolean	isSupportedVersion(String databaseProductName, int databaseVersion)
boolean	isTransactional() Determines if the JDBC data source supports transactions or not.
String	rewriteColumnType(ColumnType columnType, Integer columnSize) Rewrites the name of a column type, as it is written in CREATE TABLE statements.
protected String	rewriteColumnTypeInternal(String columnType, Object columnParameter)
String	rewriteFilterItem(FilterItem item)
protected String	rewriteFromClause(Query query, FromClause fromClause)
String	rewriteFromItem(FromItem item)
protected String	rewriteFromItem(Query query, FromItem item)
protected String	rewriteGroupByClause(Query query, GroupByClause groupByClause)
protected String	rewriteGroupByItem(Query query, GroupByItem item)
protected String	rewriteHavingClause(Query query, FilterClause havingClause)
protected String	rewriteOrderByClause(Query query, OrderByClause orderByClause)
protected String	rewriteOrderByItem(Query query, OrderByItem item)
String	rewriteQuery(Query query)
protected String	rewriteSelectClause(Query query, SelectClause selectClause)
protected String	rewriteSelectItem(Query query, SelectItem item)
protected String	rewriteWhereClause(Query query, FilterClause whereClause)
void	setStatementParameter(PreparedStatement st, int valueIndex, Column column, Object value) Method which handles the action of setting a parameterized value on a statement.
protected Time	toTime(Date value)
protected Timestamp	toTimestamp(Date value)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.metamodel.jdbc.dialects.IQueryRewriter

escapeQuotes, isAggregateFunctionSupported, isFirstRowSupported, isMaxRowsSupported, isPrimaryKeySupported, isScalarFunctionSupported

Constructor Detail

AbstractQueryRewriter

public AbstractQueryRewriter(JdbcDataContext dataContext)

Method Detail

getDataContext

public JdbcDataContext getDataContext()

isTransactional

public boolean isTransactional()

Description copied from interface: IQueryRewriter

Determines if the JDBC data source supports transactions or not. Usually this is the case since JDBC is designed for ACID compliant databases, but in some cases the JDBC interface is used also to facilitate connectivity to non-transactional data source such as Apache Hive and others.

Specified by:

isTransactional in interface IQueryRewriter

Returns:

getColumnType

public ColumnType getColumnType(int jdbcType,
                                String nativeType,
                                Integer columnSize)

Description copied from interface: IQueryRewriter

Gets the column type for a specific JDBC type (as defined in Types), native type name and column size.

Specified by:

getColumnType in interface IQueryRewriter

Returns:

rewriteQuery

public String rewriteQuery(Query query)

Specified by:

rewriteQuery in interface IQueryRewriter

isSchemaIncludedInColumnPaths

public boolean isSchemaIncludedInColumnPaths()

beforeRewrite

protected Query beforeRewrite(Query query)

Method to modify query before rewriting begins. Overwrite this method if you want to change parts of the query that are not just rendering related. Cloning the query before modifying is recommended in order to not violate referential integrity of clients (the query is mutable).

Parameters:

query -

Returns:

the modified query

rewriteColumnType

public String rewriteColumnType(ColumnType columnType,
                                Integer columnSize)

Description copied from interface: IQueryRewriter

Rewrites the name of a column type, as it is written in CREATE TABLE statements. Some databases dont support all column types, or have different names for them. The implementation of this method will do that conversion.

Specified by:

rewriteColumnType in interface IQueryRewriter

Parameters:

columnType - the (non-null) ColumnType to rewrite

columnSize - the (possibly null) column size that may or may not have been specified

Returns:

rewriteColumnTypeInternal

protected String rewriteColumnTypeInternal(String columnType,
                                           Object columnParameter)

rewriteOrderByClause

protected String rewriteOrderByClause(Query query,
                                      OrderByClause orderByClause)

rewriteFromItem

public String rewriteFromItem(FromItem item)

Specified by:

rewriteFromItem in interface IQueryRewriter

rewriteOrderByItem

protected String rewriteOrderByItem(Query query,
                                    OrderByItem item)

rewriteHavingClause

protected String rewriteHavingClause(Query query,
                                     FilterClause havingClause)

rewriteGroupByClause

protected String rewriteGroupByClause(Query query,
                                      GroupByClause groupByClause)

rewriteGroupByItem

protected String rewriteGroupByItem(Query query,
                                    GroupByItem item)

rewriteWhereClause

protected String rewriteWhereClause(Query query,
                                    FilterClause whereClause)

rewriteFilterItem

public String rewriteFilterItem(FilterItem item)

Specified by:

rewriteFilterItem in interface IQueryRewriter

rewriteFromClause

protected String rewriteFromClause(Query query,
                                   FromClause fromClause)

rewriteFromItem

protected String rewriteFromItem(Query query,
                                 FromItem item)

rewriteSelectClause

protected String rewriteSelectClause(Query query,
                                     SelectClause selectClause)

rewriteSelectItem

protected String rewriteSelectItem(Query query,
                                   SelectItem item)

setStatementParameter

public void setStatementParameter(PreparedStatement st,
                                  int valueIndex,
                                  Column column,
                                  Object value)
                           throws SQLException

Description copied from interface: IQueryRewriter

Method which handles the action of setting a parameterized value on a statement. Traditionally this is done using the PreparedStatement.setObject(int, Object) method but for some types we use more specific setter methods.

Specified by:

setStatementParameter in interface IQueryRewriter

Throws:

SQLException

toTime

protected Time toTime(Date value)

toTimestamp

protected Timestamp toTimestamp(Date value)

getResultSetValue

public Object getResultSetValue(ResultSet resultSet,
                                int columnIndex,
                                Column column)
                         throws SQLException

Description copied from interface: IQueryRewriter

Retrieves a value from a JDBC ResultSet when the anticipated value is mapped to a particular column.

Specified by:

getResultSetValue in interface IQueryRewriter

Returns:

Throws:

SQLException

isSupportedVersion

protected boolean isSupportedVersion(String databaseProductName,
                                     int databaseVersion)