protected void ValidateColumnExpression(QuerySpecification qs, ColumnExpression ce)
{
// TODO: delete
// eliminate star queries
/*if (ce.ColumnReference.IsStar)
{
throw CreateException(ExceptionMessages.StarColumnNotAllowed, null, null, ce);
}*/
foreach (ColumnIdentifier ci in ce.EnumerateDescendantsRecursive<ColumnIdentifier>(null))
{
ValidateColumnIdentifier(qs, ci);
}
// *** TODO: look for duplicate aliases
}
public static SelectList Create(ColumnReference cr)
{
// Create new expression
var nsl = new SelectList();
var nce = new ColumnExpression();
nce.ColumnReference = new ColumnReference(cr);
nsl.Stack.AddLast(nce);
var nex = new Expression();
nce.Stack.AddLast(nex);
var nav = new AnyVariable();
nex.Stack.AddLast(nav);
nav.Stack.AddLast(ColumnIdentifier.Create(new ColumnReference(cr)));
return nsl;
}
private void InitializeMembers()
{
this.columnExpression = null;
this.columnIdentifier = null;
this.tableReference = null;
this.columnName = null;
this.dataType = DataType.Unknown;
this.columnAlias = null;
this.isStar = false;
this.isComplexExpression = false;
this.selectListIndex = -1;
this.columnContext = Graywulf.SqlParser.ColumnContext.None;
}
private void CopyMembers(ColumnReference old)
{
this.columnExpression = old.columnExpression;
this.columnIdentifier = old.columnIdentifier;
this.tableReference = old.tableReference;
this.columnName = old.columnName;
this.dataType = old.dataType;
this.columnAlias = old.columnAlias;
this.isStar = old.isStar;
this.isComplexExpression = old.isComplexExpression;
this.selectListIndex = old.selectListIndex;
this.columnContext = old.columnContext;
}
/// <summary>
///
/// </summary>
/// <param name="ce"></param>
/// <returns></returns>
/// <remarks></remarks>
public static ColumnReference Interpret(ColumnExpression ce)
{
var exp = ce.FindDescendant<Expression>();
var cr = new ColumnReference();
if (exp.IsSingleColumn)
{
cr.isComplexExpression = false;
cr = Interpret(exp.FindDescendantRecursive<ColumnIdentifier>());
}
else
{
cr.isComplexExpression = true;
}
ColumnAlias ca = ce.FindDescendant<ColumnAlias>();
if (ca != null)
{
cr.columnAlias = ca.Value;
}
cr.columnExpression = ce;
return cr;
}
public abstract bool WriteColumnExpression(ColumnExpression node);
/// <summary>
/// Writes a column expression
/// </summary>
/// <param name="node"></param>
/// <returns></returns>
public virtual void WriteColumnExpression(ColumnExpression node)
{
// A column expression is in the form of an expression,
// optionally followed by a column alias in the form of
// 'AS alias'
if (resolveNames)
{
// Write the expression first as it is
var exp = node.FindDescendant<Expression>();
WriteNode(exp);
// If it's not a * column and there's an alias, write it
if (!node.ColumnReference.IsStar && !String.IsNullOrEmpty(node.ColumnReference.ColumnAlias))
{
Writer.Write(
" AS {0}",
QuoteIdentifier(node.ColumnReference.ColumnAlias));
}
}
else
{
// Fall back to original behavior
base.WriteNode(node);
}
}