protected virtual string GetOperator(BinaryExpression u)
{
switch (u.NodeType)
{
case SqlExpressionType.Add:
return "+";
case SqlExpressionType.Subtract:
return "-";
case SqlExpressionType.Multiply:
return "*";
case SqlExpressionType.Divide:
return "/";
case SqlExpressionType.Modulo:
return "%";
case SqlExpressionType.And:
return "AND";
case SqlExpressionType.Or:
return "OR";
case SqlExpressionType.LessThan:
return "<";
case SqlExpressionType.LessThanOrEqual:
return "<=";
case SqlExpressionType.GreaterThan:
return ">";
case SqlExpressionType.GreaterThanOrEqual:
return ">=";
case SqlExpressionType.Equal:
return "=";
case SqlExpressionType.NotEqual:
return "<>";
case SqlExpressionType.RightShift:
return ">>";
case SqlExpressionType.LeftShift:
return "<<";
case SqlExpressionType.ExclusiveOr:
return "^";
default:
throw new NotSupportedException("不支持的操作符：" + u.NodeType);
}
}
protected override SqlExpression VisitBinary(BinaryExpression expr)
{
this.Write("(");
this.Visit(expr.Left);
this.Write(") ");
this.Write(GetOperator(expr));
this.Write(" (");
this.Visit(expr.Right);
this.Write(") ");
return expr;
}