git-svn-id: https://svn.jboss.org/repos/hibernate/core/trunk@15281 1b8cb986-b30d-0410-93ca-fae66ebed9b2
This commit is contained in:
Steve Ebersole 2008-10-08 11:44:03 +00:00
parent 4c110150e4
commit 0741fdc495
1 changed files with 79 additions and 46 deletions

View File

@ -32,73 +32,106 @@ import org.hibernate.HibernateException;
import org.hibernate.type.Type;
/**
* An object-oriented representation of a query result set projection
* in a <tt>Criteria</tt> query. Built-in projection types are provided
* by the <tt>Projections</tt> factory class.
* This interface might be implemented by application classes that
* define custom projections.
* An object-oriented representation of a query result set projection in a {@link Criteria} query.
* Built-in projection types are provided by the {@link Projections} factory class. This interface might be
* implemented by application classes that define custom projections.
*
* @see Projections
* @see org.hibernate.Criteria
* @author Gavin King
* @author Steve Ebersole
* @see Projections
* @see Criteria
*/
public interface Projection extends Serializable {
/**
* Render the SQL fragment
* @param criteriaQuery
* @param columnAlias
* @return String
* @throws HibernateException
* Render the SQL fragment to be used in the <tt>SELECT</tt> clause.
*
* @param criteria The local criteria to which this project is attached (for resolution).
* @param position The number of columns rendered in the <tt>SELECT</tt> clause before this projection. Generally
* speaking this is useful to ensure uniqueness of the individual columns aliases.
* @param criteriaQuery The overall criteria query instance.
* @return The SQL fragment to plug into the <tt>SELECT</tt>
* @throws HibernateException Indicates a problem performing the rendering
*/
public String toSqlString(Criteria criteria, int position, CriteriaQuery criteriaQuery)
throws HibernateException;
public String toSqlString(Criteria criteria, int position, CriteriaQuery criteriaQuery)
throws HibernateException;
/**
* Render the SQL fragment to be used in the group by clause
* @param criteriaQuery
* @param columnAlias
* @return String
* @throws HibernateException
* Render the SQL fragment to be used in the <tt>GROUP BY</tt> clause
*
* @param criteria The local criteria to which this project is attached (for resolution).
* @param criteriaQuery The overall criteria query instance.
* @return The SQL fragment to plug into the <tt>GROUP BY</tt>
* @throws HibernateException Indicates a problem performing the rendering
*/
public String toGroupSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException;
public String toGroupSqlString(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException;
/**
* Return types returned by the rendered SQL fragment
* @param criteria
* @param criteriaQuery
* @return Type[]
* @throws HibernateException
* Types returned by the rendered SQL {@link #toSqlString fragment}. In other words what are the types
* that would represent the values this projection asked to be pulled into the result set?
*
* @param criteria The local criteria to which this project is attached (for resolution).
* @param criteriaQuery The overall criteria query instance.
* @return The return types.
* @throws HibernateException Indicates a problem resolving the types
*/
public Type[] getTypes(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException;
public Type[] getTypes(Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException;
/**
* Return types for a particular user-visible alias
* Get the return types for a particular user-visible alias.
* <p/>
* Differs from {@link #getTypes(org.hibernate.Criteria, CriteriaQuery)} in that here we are only interested in
* the types related to the given criteria-level alias.
*
* @param alias The criteria-level alias for which to find types.
* @param criteria The local criteria to which this project is attached (for resolution).
* @param criteriaQuery The overall criteria query instance.
* @return The return types; expected to return null if this projection does not understand this alias.
* @throws HibernateException Indicates a problem resolving the types
*/
public Type[] getTypes(String alias, Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException;
public Type[] getTypes(String alias, Criteria criteria, CriteriaQuery criteriaQuery)
throws HibernateException;
/**
* Get the SQL select clause column aliases
* Get the SQL column aliases used by this projection for the columns it writes for inclusion into the
* <tt>SELECT</tt> clause ({@link #toSqlString}. Hibernate always uses column aliases to extract data from the
* JDBC {@link java.sql.ResultSet}, so it is important that these be implemented correctly in order for
* Hibernate to be able to extract these val;ues correctly.
*
* @param position Just as in {@link #toSqlString}, represents the number of <b>columns</b> rendered
* prior to this projection.
* @return The columns aliases.
*/
public String[] getColumnAliases(int loc);
public String[] getColumnAliases(int position);
/**
* Get the SQL select clause column aliases for a particular
* user-visible alias
* Get the SQL column aliases used by this projection for the columns it writes for inclusion into the
* <tt>SELECT</tt> clause ({@link #toSqlString} <i>for a particular criteria-level alias</i>.
*
* @param alias The criteria-level alias
* @param position Just as in {@link #toSqlString}, represents the number of <b>columns</b> rendered
* prior to this projection.
* @return The columns aliases pertaining to a particular criteria-level alias; expected to return null if
* this projection does not understand this alias.
*/
public String[] getColumnAliases(String alias, int loc);
public String[] getColumnAliases(String alias, int position);
/**
* Get the user-visible aliases for this projection
* (ie. the ones that will be passed to the
* <tt>ResultTransformer</tt>)
* Get the criteria-level aliases for this projection (ie. the ones that will be passed to the
* {@link org.hibernate.transform.ResultTransformer})
*
* @return The aliases
*/
public String[] getAliases();
/**
* Does this projection specify grouping attributes?
* Is this projection fragment (<tt>SELECT</tt> clause) also part of the <tt>GROUP BY</tt>
*
* @return True if the projection is also part of the <tt>GROUP BY</tt>; false otherwise.
*/
public boolean isGrouped();
}