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A library for relational-database-based persistence in Java.

There is a newer version: 1.7.5

//
// Depot library - a Java relational persistence library
// https://github.com/threerings/depot/blob/master/LICENSE

package com.samskivert.depot.clause;

import java.util.Collection;

import com.samskivert.depot.PersistentRecord;
import com.samskivert.depot.expression.SQLExpression;
import com.samskivert.depot.impl.FragmentVisitor;

/**
 * Represents a {@code DISTINCT [ON ]} clause. Note: You almost certainly only ever want to use
 * this in a SELECT statement.
 */
public class Distinct implements QueryClause
{
    public Distinct (SQLExpression on)
    {
        _on = on;
    }

    public SQLExpression getDistinctOn ()
    {
        return _on;
    }

    // from SQLExpression
    public Object accept (FragmentVisitor builder)
    {
        return builder.visit(this);
    }

    // from SQLExpression
    public void addClasses (Collection> classSet)
    {
    }

    /** The expression to distinguish by, for DISTINCT ON, or null for mere DISTINCT. */
    protected SQLExpression _on;

}