/// <summary>
/// 初始化 <see cref="AliasedExpression"/> 类的新实例。
/// </summary>
/// <param name="nodeType">表达式的类型。</param>
/// <param name="type">表达式的数据类型。</param>
/// <param name="alias">表的别名。</param>
public AliasedExpression(DbExpressionType nodeType, Type type, TableAlias alias)
: base(nodeType, type)
{
Alias = alias;
}
internal static SelectExpression AddRedundantSelect(this SelectExpression select, TableAlias newAlias)
{
var newColumns = select.Columns.Select(d =>
new ColumnDeclaration(d.Name,
new ColumnExpression(
d.Expression.Type,
newAlias, d.Name,
d.Expression is ColumnExpression ? ((ColumnExpression)d.Expression).MapInfo : null
)));
var newFrom = new SelectExpression(newAlias, select.Columns, select.From, select.Where, select.OrderBy, select.GroupBy, select.IsDistinct, select.Skip, select.Take, select.Segment, select.Having, select.IsReverse);
return(new SelectExpression(select.Alias, newColumns, newFrom, null, null, null, false, null, null, null, null, false));
}
public TableExpression(TableAlias alias, string name, Type entityType)
: base(DbExpressionType.Table, entityType, alias)
{
Name = name;
}
internal SubqueryColumnExpression(Type type, TableAlias alias, string name, string subquery)
: base(type, alias, name, null)
{
Subquery = subquery;
}
