builder.WriteByte('*')
	}
}

func (s Select) MergeClause(clause *Clause) {
	if s.Expression != nil {
		if s.Distinct {
			if expr, ok := s.Expression.(Expr); ok {
				expr.SQL = "DISTINCT " + expr.SQL
				clause.Expression = expr
				return
			}
		}

		clause.Expression = s.Expression
	} else {
		clause.Expression = s
	}
}

// CommaExpression represents a group of expressions separated by commas.

    <description> This is the MavenProject instance for the parent of the current POM.
    </description>
  </expression>
  <expression>
    <syntax>project.file</syntax>
    <description> This is the File instance that refers to the location of the current POM on
      disk.
    </description>
  </expression>
  <expression>
    <syntax>project.artifacts</syntax>
    <configuration>
      <![CDATA[
<dependencies>
  ...

	if !selectAST.Expression.All &&
		len(selectAST.Expression.Expressions) == 1 &&
		len(selectAST.Expression.Expressions[0].Expression.And) == 1 &&
		len(selectAST.Expression.Expressions[0].Expression.And[0].Condition) == 1 &&
		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand != nil &&
		selectAST.Expression.Expressions[0].Expression.And[0].Condition[0].Operand.Operand.Left != nil &&

import org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;

/**
 * Evaluator for plugin parameters expressions. Content surrounded by <code>${</code> and <code>}</code> is evaluated.
 * Recognized values are:
 * <table border="1">
 * <caption>Expression matrix</caption>

    }

    public Iterator<?> getIteratorForXPathExpression(String expression) {
        return context.iterate(expression);
    }

    public boolean containsXPathExpression(String expression) {
        return context.getValue(expression) != null;
    }

    public Object getValue(String expression) {
        try {
            return context.getValue(expression);
        } catch (JXPathNotFoundException e) {
            return null;

	Desc    bool
	Reorder bool
}

type OrderBy struct {
	Columns    []OrderByColumn
	Expression Expression
}

// Name where clause name
func (orderBy OrderBy) Name() string {
	return "ORDER BY"
}

// Build build where clause
func (orderBy OrderBy) Build(builder Builder) {
	if orderBy.Expression != nil {
		orderBy.Expression.Build(builder)
	} else {
		for idx, column := range orderBy.Columns {
			if idx > 0 {

	strippedTableAlias string
	strippedPathExpr   []*JSONPathElement
}

// AliasedExpression is an expression that can be optionally named
type AliasedExpression struct {
	Expression *Expression `parser:"@@"`
	As         string      `parser:"[ \"AS\" @Ident | \"AS\" @LitString ]"`
}

// Grammar for Expression
//
// Expression          → AndCondition ("OR" AndCondition)*
// AndCondition        → Condition ("AND" Condition)*

func (where Where) MergeClause(clause *Clause) {
	if w, ok := clause.Expression.(Where); ok {
		exprs := make([]Expression, len(w.Exprs)+len(where.Exprs))
		copy(exprs, w.Exprs)
		copy(exprs[len(w.Exprs):], where.Exprs)
		where.Exprs = exprs
	}

	clause.Expression = where
}

func And(exprs ...Expression) Expression {
	if len(exprs) == 0 {
		return nil
	}

	if len(exprs) == 1 {

     *  @param expression A valid XPath string.
     *  @return A XPathNodes, should never be null.
     *
     * @throws XPathExpressionException if an XPath expression error occurs.
     */
    public XPathNodes selectNodeList(final Node contextNode, final String expression) throws XPathExpressionException {
        return xPath.evaluateExpression(expression, contextNode, XPathNodes.class);
    }

    /**

      </codeSegments>
    </class>
    <class>
      <version>1.0.0</version>
      <name>Expression</name>
      <description>A plugin parameter expression supported by Maven</description>
      <fields>
        <field>
          <version>1.0.0</version>
          <name>syntax</name>
          <description>The syntax of the expression</description>
          <type>String</type>
          <required>true</required>
        </field>