public override ISqlNode VisitSelectStatementNode(SelectStatementNode node, object parameter)
{
if (Processed)
{
return(node);
}
if (RowNumberColumnSpecified)
{
return(base.VisitSelectStatementNode(node, parameter));
}
Processed = true;
var subStatement = new SelectStatementNode();
subStatement.SelectClauseNode = node.SelectClauseNode;
subStatement.FromClauseNode = node.FromClauseNode;
subStatement.WhereClauseNode = node.WhereClauseNode;
subStatement.GroupByClauseNode = node.GroupByClauseNode;
subStatement.HavingClauseNode = node.HavingClauseNode;
subStatement.OrderByClauseNode = node.OrderByClauseNode;
var selectNode = new SelectClauseNode("select");
selectNode.AddNode(new FragmentNode(" * "));
var fromNode = new FromClauseNode("from");
fromNode.AddNode(new FragmentNode($" ( select temp_.*, rownum {RowNumberColumnName} from ( "));
fromNode.AddNode(subStatement);
fromNode.AddNode(new FragmentNode(" ) temp_ ) "));
var whereNode = new WhereClauseNode("where");
whereNode.AddNode(new FragmentNode(" "));
if (Offset >= 0)
{
whereNode.AddNode(new FragmentNode($"{RowNumberColumnName} > "));
whereNode.AddNode(new FragmentNode(Offset.ToString()));
}
if (Limit > 0)
{
if (Offset >= 0)
{
whereNode.AddNode(new FragmentNode(" and "));
}
whereNode.AddNode(new FragmentNode($"{RowNumberColumnName} <= "));
var bias = Offset < 0 ? 0 : Offset;
whereNode.AddNode(new FragmentNode((bias + Limit).ToString()));
}
var result = new SelectStatementNode();
result.SelectClauseNode = selectNode;
result.FromClauseNode = fromNode;
result.WhereClauseNode = whereNode;
result.ForUpdateClauseNode = node.ForUpdateClauseNode;
result.OptionClauseNode = node.OptionClauseNode;
return(result);
}
private void ParseWhereNode()
{
Validate();
var node = new WhereClauseNode(_token);
if (IsInWhereClauseAwareNode())
{
RemoveNodesTo <IWhereClauseAwareNode>();
var whereClauseAwareNode = (IWhereClauseAwareNode)Peek();
whereClauseAwareNode.WhereClauseNode = node;
}
else
{
AppendNode(node);
}
_nodeStack.Push(node);
}
public override ISqlNode VisitSelectStatementNode(SelectStatementNode node, object parameter)
{
if (Processed)
{
return(node);
}
Processed = true;
var originalOrderBy = node.OrderByClauseNode;
if (originalOrderBy == null)
{
throw new SqlTransformException(ExceptionMessageId.Esp2201);
}
var subStatement = new SelectStatementNode();
subStatement.SelectClauseNode = node.SelectClauseNode;
subStatement.FromClauseNode = node.FromClauseNode;
subStatement.WhereClauseNode = node.WhereClauseNode;
subStatement.GroupByClauseNode = node.GroupByClauseNode;
subStatement.HavingClauseNode = node.HavingClauseNode;
var orderBy = new OrderByClauseNode(originalOrderBy.WordNode);
foreach (var child in originalOrderBy.Children)
{
if (child is WordNode wordNode)
{
var word = wordNode.Word;
var names = word.Split('.');
if (names.Length == 2)
{
orderBy.AddNode(new WordNode("temp_." + names[1]));
}
else
{
orderBy.AddNode(child);
}
}
else
{
orderBy.AddNode(child);
}
}
var selectNode = new SelectClauseNode("select");
selectNode.AddNode(new FragmentNode(" * "));
var fromNode = new FromClauseNode("from");
fromNode.AddNode(new FragmentNode(" ( select temp_.*, row_number() over( "));
fromNode.AddNode(orderBy);
fromNode.AddNode(new FragmentNode($" ) as {RowNumberColumnName} from ( "));
fromNode.AddNode(subStatement);
fromNode.AddNode(new FragmentNode(") as temp_ ) as temp2_ "));
var whereNode = new WhereClauseNode("where");
whereNode.AddNode(new FragmentNode(" "));
if (Offset >= 0)
{
whereNode.AddNode(new FragmentNode($"{RowNumberColumnName} > "));
whereNode.AddNode(new FragmentNode(Offset.ToString()));
}
if (Limit > 0)
{
if (Offset >= 0)
{
whereNode.AddNode(new FragmentNode(" and "));
}
var bias = Offset < 0 ? 0 : Offset;
whereNode.AddNode(new FragmentNode($"{RowNumberColumnName} <= "));
whereNode.AddNode(new FragmentNode((bias + Limit).ToString()));
}
var result = new SelectStatementNode();
result.SelectClauseNode = selectNode;
result.FromClauseNode = fromNode;
result.WhereClauseNode = whereNode;
result.ForUpdateClauseNode = node.ForUpdateClauseNode;
result.OptionClauseNode = node.OptionClauseNode;
return(result);
}
public object VisitWhereClauseNode(WhereClauseNode node, Context parameter)
{
return(HandleConditionalClauseNode(node, parameter));
}
public virtual void VisitWhereClause(WhereClauseNode node) => throw new NotImplementedException();
