CaseExpression.java

/* ================================================================
 * JSQLParser : java based sql parser
 * ================================================================
 *
 * Project Info:  http://jsqlparser.sourceforge.net
 * Project Lead:  Leonardo Francalanci (leoonardoo@yahoo.it);
 *
 * (C) Copyright 2004, by Leonardo Francalanci
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 */
package net.sf.jsqlparser.expression;

import java.util.List;
import net.sf.jsqlparser.statement.select.PlainSelect;

/**
 * CASE/WHEN expression.
 *
 * Syntax:
 * <code>
 * CASE
 * WHEN condition THEN expression
 * [WHEN condition THEN expression]...
 * [ELSE expression]
 * END
 * </code>
 *
 * or <br>
 *
 * <code>
 * CASE expression
 * WHEN condition THEN expression
 * [WHEN condition THEN expression]...
 * [ELSE expression]
 * END
 * </code>
 *
 * See also: https://aurora.vcu.edu/db2help/db2s0/frame3.htm#casexp
 *  http://sybooks.sybase.com/onlinebooks/group-as/asg1251e/commands/
 *
 * ?ebt-link;pt=5954?target=%25N%15_52628_START_RESTART_N%25
 *
 *
 * @author Havard Rast Blok
 */
public class CaseExpression implements Expression {

    private Expression switchExpression;
    private List<WhenClause> whenClauses;
    private Expression elseExpression;
    private String commentCase;
    private String commentElse;
    private String commentEnd;

    /* (non-Javadoc)
     * @see net.sf.jsqlparser.expression.Expression#accept(net.sf.jsqlparser.expression.ExpressionVisitor)
     */
    @Override
    public void accept(ExpressionVisitor expressionVisitor) {
        expressionVisitor.visit(this);
    }

    /**
     * @return Returns the switchExpression.
     */
    public Expression getSwitchExpression() {
        return switchExpression;
    }

    /**
     * @param switchExpression The switchExpression to set.
     */
    public void setSwitchExpression(Expression switchExpression) {
        this.switchExpression = switchExpression;
    }

    /**
     * @return Returns the elseExpression.
     */
    public Expression getElseExpression() {
        return elseExpression;
    }

    /**
     * @param elseExpression The elseExpression to set.
     */
    public void setElseExpression(Expression elseExpression) {
        this.elseExpression = elseExpression;
    }

    /**
     * @return Returns the whenClauses.
     */
    public List<WhenClause> getWhenClauses() {
        return whenClauses;
    }

    /**
     * @param whenClauses The whenClauses to set.
     */
    public void setWhenClauses(List<WhenClause> whenClauses) {
        this.whenClauses = whenClauses;
    }

    @Override
    public String toString() {
        return (getCommentCase() != null ? getCommentCase() + " " : "") + "CASE "
                + ((switchExpression != null) ? switchExpression + " " : "")
                + PlainSelect.getStringList(whenClauses, false, false) + " "
                + ((elseExpression != null) ? (getCommentElse() != null ? getCommentElse() + " " : "")
                + "ELSE " + elseExpression + " " : "")
                + (getCommentEnd() != null ? getCommentEnd() + " " : "") + "END";
    }

    /**
     * @return the commentCase
     */
    public String getCommentCase() {
        return commentCase;
    }

    /**
     * @param commentCase the commentCase to set
     */
    public void setCommentCase(String commentCase) {
        this.commentCase = commentCase;
    }

    /**
     * @return the commentElse
     */
    public String getCommentElse() {
        return commentElse;
    }

    /**
     * @param commentElse the commentElse to set
     */
    public void setCommentElse(String commentElse) {
        this.commentElse = commentElse;
    }

    /**
     * @return the commentEnd
     */
    public String getCommentEnd() {
        return commentEnd;
    }

    /**
     * @param commentEnd the commentEnd to set
     */
    public void setCommentEnd(String commentEnd) {
        this.commentEnd = commentEnd;
    }
}