org.hibernate.dialect.pagination

Class TopLimitHandler

java.lang.Object

org.hibernate.dialect.pagination.AbstractLimitHandler

org.hibernate.dialect.pagination.TopLimitHandler

All Implemented Interfaces:

LimitHandler

public class TopLimitHandler
extends AbstractLimitHandler

Constructor Summary

Constructors

Constructor and Description
TopLimitHandler(boolean supportsVariableLimit, boolean bindLimitParametersFirst)

Method Summary

Modifier and Type	Method and Description
boolean	bindLimitParametersFirst() Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?
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	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, bindLimitParametersInReverseOrder, convertToFirstRowValue, forceLimitUsage, getMaxOrLimit, setMaxRows, supportsVariableLimit

Methods inherited from class java.lang.Object

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

Constructor Detail

TopLimitHandler

public TopLimitHandler(boolean supportsVariableLimit,
                       boolean bindLimitParametersFirst)

Method Detail

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.

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.

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.

bindLimitParametersFirst

public boolean bindLimitParametersFirst()

Description copied from class: AbstractLimitHandler

Does the LIMIT clause come at the start of the SELECT statement, rather than at the end?

Overrides:

bindLimitParametersFirst in class AbstractLimitHandler

Returns:

true if limit parameters should come before other parameters

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.