org.hibernate.criterion
Class SimpleProjection

java.lang.Object
  extended by org.hibernate.criterion.SimpleProjection
All Implemented Interfaces:
Serializable, EnhancedProjection, Projection
Direct Known Subclasses:
AggregateProjection, IdentifierProjection, PropertyProjection, RowCountProjection

public abstract class SimpleProjection
extends Object
implements EnhancedProjection

A single-column projection that may be aliased

See Also:
Serialized Form

Constructor Summary
SimpleProjection()
           
 
Method Summary
 Projection as(String alias)
           
 String[] getAliases()
          Get the criteria-level aliases for this projection (ie.
 String[] getColumnAliases(int loc)
          Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery).
 String[] getColumnAliases(int loc, Criteria criteria, CriteriaQuery criteriaQuery)
          Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery).
 String[] getColumnAliases(String alias, int loc)
          Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery) for a particular criteria-level alias.
 String[] getColumnAliases(String alias, int loc, Criteria criteria, CriteriaQuery criteriaQuery)
          Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery) for a particular criteria-level alias.
 int getColumnCount(Criteria criteria, CriteriaQuery criteriaQuery)
           
 Type[] getTypes(String alias, Criteria criteria, CriteriaQuery criteriaQuery)
          Get the return types for a particular user-visible alias.
 boolean isGrouped()
          Is this projection fragment (SELECT clause) also part of the GROUP BY
 String toGroupSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
          Render the SQL fragment to be used in the GROUP BY clause
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.hibernate.criterion.Projection
getTypes, toSqlString
 

Constructor Detail

SimpleProjection

public SimpleProjection()
Method Detail

as

public Projection as(String alias)

getColumnAliases

public String[] getColumnAliases(String alias,
                                 int loc)
Description copied from interface: Projection
Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery) for a particular criteria-level alias.

Specified by:
getColumnAliases in interface Projection
Parameters:
alias - The criteria-level alias
loc - Just as in Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery), represents the number of columns rendered prior to this projection.
Returns:
The columns aliases pertaining to a particular criteria-level alias; expected to return null if this projection does not understand this alias.

getColumnAliases

public String[] getColumnAliases(String alias,
                                 int loc,
                                 Criteria criteria,
                                 CriteriaQuery criteriaQuery)
Description copied from interface: EnhancedProjection
Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery) for a particular criteria-level alias.

Specified by:
getColumnAliases in interface EnhancedProjection
Parameters:
alias - The criteria-level alias
loc - Just as in Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery), represents the number of columns rendered prior to this projection.
criteria - The local criteria to which this project is attached (for resolution).
criteriaQuery - The overall criteria query instance.
Returns:
The columns aliases pertaining to a particular criteria-level alias; expected to return null if this projection does not understand this alias.

getTypes

public Type[] getTypes(String alias,
                       Criteria criteria,
                       CriteriaQuery criteriaQuery)
Description copied from interface: Projection
Get the return types for a particular user-visible alias.

Differs from Projection.getTypes(org.hibernate.Criteria, CriteriaQuery) in that here we are only interested in the types related to the given criteria-level alias.

Specified by:
getTypes in interface Projection
Parameters:
alias - The criteria-level alias for which to find types.
criteria - The local criteria to which this project is attached (for resolution).
criteriaQuery - The overall criteria query instance.
Returns:
The return types; expected to return null if this projection does not understand this alias.

getColumnAliases

public String[] getColumnAliases(int loc)
Description copied from interface: Projection
Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery). Hibernate always uses column aliases to extract data from the JDBC ResultSet, so it is important that these be implemented correctly in order for Hibernate to be able to extract these val;ues correctly.

Specified by:
getColumnAliases in interface Projection
Parameters:
loc - Just as in Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery), represents the number of columns rendered prior to this projection.
Returns:
The columns aliases.

getColumnCount

public int getColumnCount(Criteria criteria,
                          CriteriaQuery criteriaQuery)

getColumnAliases

public String[] getColumnAliases(int loc,
                                 Criteria criteria,
                                 CriteriaQuery criteriaQuery)
Description copied from interface: EnhancedProjection
Get the SQL column aliases used by this projection for the columns it writes for inclusion into the SELECT clause (Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery). Hibernate always uses column aliases to extract data from the JDBC ResultSet, so it is important that these be implemented correctly in order for Hibernate to be able to extract these val;ues correctly.

Specified by:
getColumnAliases in interface EnhancedProjection
Parameters:
loc - Just as in Projection.toSqlString(org.hibernate.Criteria, int, org.hibernate.criterion.CriteriaQuery), represents the number of columns rendered prior to this projection.
criteria - The local criteria to which this project is attached (for resolution).
criteriaQuery - The overall criteria query instance.
Returns:
The columns aliases.

getAliases

public String[] getAliases()
Description copied from interface: Projection
Get the criteria-level aliases for this projection (ie. the ones that will be passed to the ResultTransformer)

Specified by:
getAliases in interface Projection
Returns:
The aliases

toGroupSqlString

public String toGroupSqlString(Criteria criteria,
                               CriteriaQuery criteriaQuery)
Description copied from interface: Projection
Render the SQL fragment to be used in the GROUP BY clause

Specified by:
toGroupSqlString in interface Projection
Parameters:
criteria - The local criteria to which this project is attached (for resolution).
criteriaQuery - The overall criteria query instance.
Returns:
The SQL fragment to plug into the GROUP BY

isGrouped

public boolean isGrouped()
Description copied from interface: Projection
Is this projection fragment (SELECT clause) also part of the GROUP BY

Specified by:
isGrouped in interface Projection
Returns:
True if the projection is also part of the GROUP BY; false otherwise.


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