INode MakeSubstring(FunctionCall substringCall)
{
if (substringCall == null)
{
throw new ArgumentNullException("substringCall");
}
substringCall.Name = TailorUtil.GetCapitalized(TailorUtil.MID);
ExpressionItem val = substringCall.ExpressionArguments;
if (val == null)
{
throw new InvalidOperationException("No parameters for SUBSTRING.");
}
ExpressionItem start = val.Next;
if (start == null)
{
throw new InvalidOperationException("Too few parameters for SUBSTRING.");
}
ExpressionItem len = start.Next;
INode cond = MakeNotNullCheck(start); // Mid actually handles NULL
// in the first parameter
if (len == null)
{
// We don't need to add length in the normal case, but it's
// useful when the start position is too large and the call
// ought to fail (which Mid doesn't, unless it's called with
// a negative length).
IExpression argument = TailorUtil.MakeLenArg(start.Expression,
val.Expression, "Len");
start.Add(new ExpressionItem(argument));
}
else
{
if (len.Next != null)
{
throw new InvalidOperationException("Too many parameters for SUBSTRING.");
}
}
if (cond == null)
{
return(substringCall);
}
else
{
FunctionCall iifCall = new FunctionCall("Iif");
iifCall.ExpressionArguments = new ExpressionItem(cond);
iifCall.ExpressionArguments.Add(new ExpressionItem(NullValue.Value));
iifCall.ExpressionArguments.Add(new ExpressionItem(substringCall));
return(iifCall);
}
}
public override void PerformBefore(DbObject node)
{
if (node == null)
{
throw new ArgumentNullException("node");
}
if (!node.HasNext)
{
if (TailorUtil.IsSysdate(node.Identifier))
{
ReplaceTerm(node, new FunctionCall(
TailorUtil.GetCapitalized(TailorUtil.NOW)));
}
if (!m_inSelectItems && (m_selectItemAliases != null))
{
string key = Identifier.Canonicalize(node.Identifier.ID);
if (m_selectItemAliases.ContainsKey(key))
{
AliasedItem orig = m_selectItemAliases[key];
ReplaceTerm(node, orig.Item.Clone());
}
}
}
base.PerformBefore(node);
}
public override void PerformBefore(FunctionCall node)
{
if (node == null)
{
throw new ArgumentNullException("node");
}
base.PerformBefore(node);
string name = node.Name.ToLowerInvariant();
if (name.Equals(TailorUtil.GETDATE))
{
node.Name = TailorUtil.GetCapitalized(TailorUtil.NOW);
}
else if (name.Equals(TailorUtil.COALESCE))
{
CoalesceToIif(node);
}
}