org.hibernate.dialect.pagination

Class SybaseASE157LimitHandler

java.lang.Object

org.hibernate.dialect.pagination.AbstractLimitHandler

org.hibernate.dialect.pagination.SybaseASE157LimitHandler

All Implemented Interfaces:

LimitHandler

public class SybaseASE157LimitHandler
extends AbstractLimitHandler

This limit handler is very conservative and is only triggered in simple cases involving a select or select distinct.

Note that if the query already contains "top" just after the select or select distinct, we don't add anything to the query. It might just be a column name but, in any case, we just don't add the top clause and default to the previous behavior so it's not an issue.

Constructor Summary

Constructors

Constructor and Description
SybaseASE157LimitHandler()

Method Summary

Modifier and Type	Method and Description
String	processSql(String sql, RowSelection selection) Return processed SQL query.
boolean	supportsLimit() Does this handler support some form of limiting query results via a SQL clause?
boolean	supportsLimitOffset() Does this handler's LIMIT support (if any) additionally support specifying an offset?
boolean	supportsVariableLimit() Does this handler support bind variables (i.e., prepared statement parameters) for its limit/offset?
boolean	useMaxForLimit() Does the LIMIT clause take a "maximum" row number instead of a total number of returned rows? This is easiest understood via an example.

Methods inherited from class org.hibernate.dialect.pagination.AbstractLimitHandler

bindLimitParameters, bindLimitParametersAtEndOfQuery, bindLimitParametersAtStartOfQuery, bindLimitParametersFirst, bindLimitParametersInReverseOrder, convertToFirstRowValue, forceLimitUsage, getMaxOrLimit, setMaxRows

Methods inherited from class java.lang.Object

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

Constructor Detail

SybaseASE157LimitHandler

public SybaseASE157LimitHandler()

Method Detail

processSql

public String processSql(String sql,
                         RowSelection selection)

Description copied from interface: LimitHandler

Return processed SQL query.

Specified by:

processSql in interface LimitHandler

Overrides:

processSql in class AbstractLimitHandler

Parameters:

sql - the SQL query to process.

selection - the selection criteria for rows.

Returns:

Query statement with LIMIT clause applied.

supportsLimit

public boolean supportsLimit()

Description copied from interface: LimitHandler

Does this handler support some form of limiting query results via a SQL clause?

Specified by:

supportsLimit in interface LimitHandler

Overrides:

supportsLimit in class AbstractLimitHandler

Returns:

True if this handler supports some form of LIMIT.

supportsLimitOffset

public boolean supportsLimitOffset()

Description copied from interface: LimitHandler

Does this handler's LIMIT support (if any) additionally support specifying an offset?

Specified by:

supportsLimitOffset in interface LimitHandler

Overrides:

supportsLimitOffset in class AbstractLimitHandler

Returns:

True if the handler supports an offset within the limit support.

useMaxForLimit

public boolean useMaxForLimit()

Description copied from class: AbstractLimitHandler

Does the LIMIT clause take a "maximum" row number instead of a total number of returned rows?

This is easiest understood via an example. Consider you have a table with 20 rows, but you only want to retrieve rows number 11 through 20. Generally, a limit with offset would say that the offset = 11 and the limit = 10 (we only want 10 rows at a time); this is specifying the total number of returned rows. Some dialects require that we instead specify offset = 11 and limit = 20, where 20 is the "last" row we want relative to offset (i.e. total number of rows = 20 - 11 = 9)

So essentially, is limit relative from offset? Or is limit absolute?

Overrides:

useMaxForLimit in class AbstractLimitHandler

Returns:

True if limit is relative from offset; false otherwise.

supportsVariableLimit

public boolean supportsVariableLimit()

Description copied from class: AbstractLimitHandler

Does this handler support bind variables (i.e., prepared statement parameters) for its limit/offset?

Overrides:

supportsVariableLimit in class AbstractLimitHandler

Returns:

True if bind variables can be used; false otherwise.