org.apache.metamodel.jdbc.dialects

Interface IQueryRewriter

All Known Implementing Classes:

AbstractQueryRewriter, DB2QueryRewriter, DefaultQueryRewriter, H2QueryRewriter, HiveQueryRewriter, HsqldbQueryRewriter, LimitOffsetQueryRewriter, MysqlQueryRewriter, OracleQueryRewriter, PostgresqlQueryRewriter, SQLServerQueryRewriter

public interface IQueryRewriter

A query rewriter can be used for rewriting (part of) a query's string representation. This is usefull for databases that deviate from the SQL 99 compliant syntax which is delievered by the query and it's query item's toString() methods.

See Also:

AbstractQueryRewriter, JdbcDataContext

Method Summary

Methods

Modifier and Type	Method and Description
String	escapeQuotes(String item) Escapes the quotes within a String literal of a query item.
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.
boolean	isFirstRowSupported() Gets whether this query rewriter is able to write the "First row" query property to the query string.
boolean	isMaxRowsSupported() Gets whether this query rewriter is able to write the "Max rows" query property to the query string.
boolean	isScalarFunctionSupported(ScalarFunction function) Determines whether a specific scalar function is supported by the database or not.
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.
String	rewriteFilterItem(FilterItem whereItem)
String	rewriteFromItem(FromItem item)
String	rewriteQuery(Query query)

Method Detail

rewriteFromItem

String rewriteFromItem(FromItem item)

rewriteQuery

String rewriteQuery(Query query)

rewriteFilterItem

String rewriteFilterItem(FilterItem whereItem)

isMaxRowsSupported

boolean isMaxRowsSupported()

Gets whether this query rewriter is able to write the "Max rows" query property to the query string.

Returns:

whether this query rewriter is able to write the "Max rows" query property to the query string.

isFirstRowSupported

boolean isFirstRowSupported()

Gets whether this query rewriter is able to write the "First row" query property to the query string.

Returns:

whether this query rewriter is able to write the "First row" query property to the query string.

isScalarFunctionSupported

boolean isScalarFunctionSupported(ScalarFunction function)

Determines whether a specific scalar function is supported by the database or not. If the function is not supported then MetaModel will handle the function on the client side.

Parameters:

function -

Returns:

escapeQuotes

String escapeQuotes(String item)

Escapes the quotes within a String literal of a query item.

Returns:

String item with quotes escaped.

rewriteColumnType

String rewriteColumnType(ColumnType columnType,
                       Integer columnSize)

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.

Parameters:

columnType - the (non-null) ColumnType to rewrite

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

Returns:

getColumnType

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.

Parameters:

jdbcType -

nativeType -

columnSize -

Returns:

isTransactional

boolean isTransactional()

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.

Returns: