io.ebean.config.dbplatform

Class DbViewHistorySupport

java.lang.Object

io.ebean.config.dbplatform.DbViewHistorySupport

All Implemented Interfaces:

DbHistorySupport

Direct Known Subclasses:

H2HistorySupport, MySqlHistorySupport, PostgresHistorySupport

public abstract class DbViewHistorySupport
extends Object
implements DbHistorySupport

Database view based implementation of DbHistorySupport.

These implementations have explicit history tables, a view to union the base table and history table and triggers to maintain the history.

Constructor Summary

Constructors

Constructor and Description
DbViewHistorySupport()

Method Summary

Modifier and Type	Method and Description
String	getAsOfPredicate(String asOfTableAlias, String asOfSysPeriod) Return the 'as of' predicate clause appended to the end of the normal query predicates.
String	getAsOfViewSuffix(String asOfViewSuffix) Returns the configured view suffix.
int	getBindCount() Return 2 if we have effective start and effective end as 2 columns.
String	getSysPeriodLower(String tableAlias, String sysPeriod) Return the lower bound column prepended with the table alias.
String	getSysPeriodUpper(String tableAlias, String sysPeriod) Return the upper bound column prepended with the table alias.
String	getVersionsBetweenSuffix(String asOfViewSuffix) Returns the configured view suffix (same as getAsOfViewSuffix()).
boolean	isStandardsBased() Return true if the implementation is SQL2011 standards based.

Methods inherited from class java.lang.Object

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

Constructor Detail

DbViewHistorySupport

public DbViewHistorySupport()

Method Detail

isStandardsBased

public boolean isStandardsBased()

Description copied from interface: DbHistorySupport

Return true if the implementation is SQL2011 standards based.

Non standards based means we need to add additional predicates into the JOIN ON clause and add an additional predicate for the base table.

Specified by:

isStandardsBased in interface DbHistorySupport

getAsOfViewSuffix

public String getAsOfViewSuffix(String asOfViewSuffix)

Returns the configured view suffix.

Specified by:

getAsOfViewSuffix in interface DbHistorySupport

Parameters:

asOfViewSuffix - the configured view suffix (typically "_with_history").

Returns:

The suffix appended after the base table name in the from and join clauses.

getVersionsBetweenSuffix

public String getVersionsBetweenSuffix(String asOfViewSuffix)

Returns the configured view suffix (same as getAsOfViewSuffix()).

Specified by:

getVersionsBetweenSuffix in interface DbHistorySupport

Parameters:

asOfViewSuffix - the configured view suffix (typically "_with_history").

getBindCount

public int getBindCount()

Return 2 if we have effective start and effective end as 2 columns. Note that for postgres we can use a single range type so that returns 1.

Specified by:

getBindCount in interface DbHistorySupport

getAsOfPredicate

public String getAsOfPredicate(String asOfTableAlias,
                               String asOfSysPeriod)

Return the 'as of' predicate clause appended to the end of the normal query predicates.

Specified by:

getAsOfPredicate in interface DbHistorySupport

Parameters:

asOfTableAlias - The table alias this predicate is added for

asOfSysPeriod - The name of the 'sys_period' column used for effective date time range.

Returns:

The predicate containing a single ? bind parameter which will be bound to the 'as at' timestamp value

getSysPeriodLower

public String getSysPeriodLower(String tableAlias,
                                String sysPeriod)

Return the lower bound column prepended with the table alias.

Specified by:

getSysPeriodLower in interface DbHistorySupport

Parameters:

tableAlias - the table alias

sysPeriod - the name of the sys_period column

getSysPeriodUpper

public String getSysPeriodUpper(String tableAlias,
                                String sysPeriod)

Return the upper bound column prepended with the table alias.

Specified by:

getSysPeriodUpper in interface DbHistorySupport

Parameters:

tableAlias - the table alias

sysPeriod - the name of the sys_period column