public override AstElement Clone(Dictionary<AstElement, AstElement> alreadyClonedElements)
{
SelectColumn result = new SelectColumn();
if (_expression != null)
result.Expression = (ExpressionNode)_expression.Clone(alreadyClonedElements);
result.Alias = _alias;
return result;
}
public override AstElement Clone(Dictionary <AstElement, AstElement> alreadyClonedElements)
{
SelectColumn result = new SelectColumn();
if (_expression != null)
{
result.Expression = (ExpressionNode)_expression.Clone(alreadyClonedElements);
}
result.Alias = _alias;
return(result);
}
private void WriteColumns(SelectColumn[] selectColumns)
{
for (int i = 0; i < selectColumns.Length; i++)
{
SelectColumn selectSelectColumn = selectColumns[i];
_xmlWriter.WriteStartElement("column");
_xmlWriter.WriteAttributeString("index", XmlConvert.ToString(i));
_xmlWriter.WriteAttributeString("isStar", XmlConvert.ToString(selectSelectColumn.IsAsterisk));
if (selectSelectColumn.Alias != null)
_xmlWriter.WriteAttributeString("alias", selectSelectColumn.Alias.ToSource());
if (selectSelectColumn.Expression != null)
Visit(selectSelectColumn.Expression);
_xmlWriter.WriteEndElement();
}
}
private void WriteColumns(SelectColumn[] selectColumns)
{
for (int i = 0; i < selectColumns.Length; i++)
{
SelectColumn selectSelectColumn = selectColumns[i];
_xmlWriter.WriteStartElement("column");
_xmlWriter.WriteAttributeString("index", XmlConvert.ToString(i));
_xmlWriter.WriteAttributeString("isStar", XmlConvert.ToString(selectSelectColumn.IsAsterisk));
if (selectSelectColumn.Alias != null)
{
_xmlWriter.WriteAttributeString("alias", selectSelectColumn.Alias.ToSource());
}
if (selectSelectColumn.Expression != null)
{
Visit(selectSelectColumn.Expression);
}
_xmlWriter.WriteEndElement();
}
}
private void ValidateColumnNames(SelectColumn[] columns, CommonTableExpression commonTableExpression)
{
if (commonTableExpression.ColumnNames == null)
{
// Check that all columns have aliases.
for (int i = 0; i < columns.Length; i++)
{
SelectColumn selectColumn = columns[i];
if (selectColumn.Alias == null)
ErrorReporter.NoColumnAliasSpecified(commonTableExpression.TableNameSourceRange, i, commonTableExpression.TableName);
}
}
else
{
if (commonTableExpression.ColumnNames.Length < columns.Length)
ErrorReporter.CteHasMoreColumnsThanSpecified(commonTableExpression.TableName);
else if (commonTableExpression.ColumnNames.Length > columns.Length)
ErrorReporter.CteHasFewerColumnsThanSpecified(commonTableExpression.TableName);
else
{
// Check that all specified column names are unique.
Dictionary<string, object> nameSet = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
foreach (Identifier columnName in commonTableExpression.ColumnNames)
{
if (nameSet.ContainsKey(columnName.Text))
ErrorReporter.CteHasDuplicateColumnName(columnName, commonTableExpression.TableName);
else
nameSet.Add(columnName.Text, null);
}
}
if (!ErrorReporter.ErrorsSeen)
{
// Write explictly given column names into the real column list as aliases.
for (int i = 0; i < columns.Length; i++)
columns[i].Alias = commonTableExpression.ColumnNames[i];
}
}
}
private void ResolveOrderBy(SelectColumn[] inputSelectColumns, IEnumerable<OrderByColumn> orderByColumns)
{
// 1. ORDER BY expressions allow simple integer literals. They refer to an expression
// in the selection list.
//
// 2. ORDER BY allows to specify the column alias.
foreach (OrderByColumn orderByColumn in orderByColumns)
{
orderByColumn.ColumnIndex = -1;
// Check for positional form.
bool expressionResolved = false;
LiteralExpression literalExpression = orderByColumn.Expression as LiteralExpression;
if (literalExpression != null && literalExpression.IsInt32Value)
{
int selectionListPos = literalExpression.AsInt32;
if (selectionListPos < 1 || selectionListPos > inputSelectColumns.Length)
ErrorReporter.OrderByColumnPositionIsOutOfRange(selectionListPos);
else
{
int index = selectionListPos - 1;
orderByColumn.Expression = inputSelectColumns[index].Expression;
orderByColumn.ColumnIndex = index;
}
expressionResolved = true;
}
else
{
// Check for column alias form.
NameExpression nameExpression = orderByColumn.Expression as NameExpression;
if (nameExpression != null)
{
for (int i = 0; i < inputSelectColumns.Length; i++)
{
SelectColumn selectColumn = inputSelectColumns[i];
if (nameExpression.Name == selectColumn.Alias)
{
orderByColumn.Expression = selectColumn.Expression;
orderByColumn.ColumnIndex = i;
expressionResolved = true;
break;
}
}
}
}
if (!expressionResolved)
{
orderByColumn.Expression = VisitExpression(orderByColumn.Expression);
for (int i = 0; i < inputSelectColumns.Length; i++)
{
SelectColumn selectColumn = inputSelectColumns[i];
if (selectColumn.Expression.IsStructuralEqualTo(orderByColumn.Expression))
{
orderByColumn.ColumnIndex = i;
break;
}
}
}
}
}
