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The jBATIS persistence framework will help you to significantly reduce the amount of Java code that you normally need to access a relational database. iBATIS simply maps JavaBeans to SQL statements using a very simple XML descriptor.

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package org.ibatis.persist.impl.expression;

import org.ibatis.persist.criteria.Expression;

import org.ibatis.persist.impl.CriteriaBuilderImpl;
import org.ibatis.persist.impl.Renderable;
import org.ibatis.persist.impl.RenderingContext;

/**
 * Models an ANSI SQL NULLIF expression.  NULLIF is a specialized CASE statement.
 */
@SuppressWarnings("unchecked")
public class NullifExpression extends ExpressionImpl {
	private final Expression primaryExpression;
	private final Expression secondaryExpression;

	public NullifExpression(
			CriteriaBuilderImpl criteriaBuilder,
			Class javaType,
			Expression primaryExpression,
			Expression secondaryExpression) {
		super( criteriaBuilder, (Class)determineType(javaType, primaryExpression) );
		this.primaryExpression = primaryExpression;
		this.secondaryExpression = secondaryExpression;
	}

	public NullifExpression(
			CriteriaBuilderImpl criteriaBuilder,
			Class javaType,
			Expression primaryExpression,
			Object secondaryExpression) {
		super( criteriaBuilder, (Class)determineType(javaType, primaryExpression) );
		this.primaryExpression = primaryExpression;
		this.secondaryExpression = new LiteralExpression( criteriaBuilder, secondaryExpression );
	}

	private static Class determineType(Class javaType, Expression primaryExpression) {
		return javaType != null ? javaType : primaryExpression.getJavaType();
	}

	public Expression getPrimaryExpression() {
		return primaryExpression;
	}

	public Expression getSecondaryExpression() {
		return secondaryExpression;
	}

    public void render(RenderingContext rc) {
        rc.append("nullif(");
        ((Renderable) getPrimaryExpression()).render(rc);
        rc.append(',');
        ((Renderable) getSecondaryExpression()).render(rc);
        rc.append(")");
    }

    public void renderProjection(RenderingContext rc) {
        render(rc);
        if (getAlias() != null) {
            rc.append(" AS ").append(getAlias());
        }
    }
}