org.hrorm

Enum ChildSelectStrategy

java.lang.Object

java.lang.Enum<ChildSelectStrategy>

org.hrorm.ChildSelectStrategy

All Implemented Interfaces:

Serializable, Comparable<ChildSelectStrategy>

public enum ChildSelectStrategy
extends Enum<ChildSelectStrategy>

Enum Constant Summary

Enum Constants

Enum Constant and Description
ByKeysInClause When reading a collection of entity records, for each child table, issue a select statement with an in-clause containing the IDs of the parent records.
Standard The default strategy.
SubSelectInClause When reading a collection of entity records, for each child table, issue a select statement with an in-clause containing a sub-select for the primary keys of the records originally searched for.

Method Summary

Modifier and Type	Method and Description
static ChildSelectStrategy	valueOf(String name) Returns the enum constant of this type with the specified name.
static ChildSelectStrategy[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

Standard

public static final ChildSelectStrategy Standard

The default strategy. A select will be issued for each child table of the entity for each record found. This is the so-called N+1 Query problem.

ByKeysInClause

public static final ChildSelectStrategy ByKeysInClause

When reading a collection of entity records, for each child table, issue a select statement with an in-clause containing the IDs of the parent records. E.g. generate SQL that looks something like SELECT * FROM CHILD WHERE PARENT_ID IN ( ?, ?, ?, ... )

SubSelectInClause

public static final ChildSelectStrategy SubSelectInClause

When reading a collection of entity records, for each child table, issue a select statement with an in-clause containing a sub-select for the primary keys of the records originally searched for. E.g. generate SQL that looks something like SELECT * FROM CHILD WHERE PARENT_ID IN (SELECT ID FROM PARENT WHERE ...)

Method Detail

values

public static ChildSelectStrategy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ChildSelectStrategy c : ChildSelectStrategy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ChildSelectStrategy valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null