protected override ISqlNode OnChildNode(ISqlNode node)
{
if (node.NodeName == "sql_query_expression") {
QueryExpression = node as SqlQueryExpressionNode;
} else if (node.NodeName == "order_opt") {
GetOrderBy(node);
}
return base.OnChildNode(node);
}
/// <inheritdoc/>
protected override ISqlNode OnChildNode(ISqlNode node)
{
if (node is SqlQueryExpressionNode) {
Query = (SqlQueryExpressionNode)node;
} else if (node.NodeName == "select_as_opt") {
Alias = (IdentifierNode)node.ChildNodes.FirstOrDefault();
}
return base.OnChildNode(node);
}
public virtual void VisitQueryExpression(SqlQueryExpressionNode node)
{
}
private IEnumerable<SelectColumn> GetSelectColumns(SqlQueryExpressionNode node)
{
if (node.IsAll) {
return new[] {new SelectColumn(SqlExpression.Reference(new ObjectName("*")))};
}
var items = new List<SelectColumn>();
foreach (var item in node.SelectItems) {
SqlExpression exp;
if (item.Name != null) {
exp = SqlExpression.Reference(ObjectName.Parse(item.Name.Name));
} else if (item.Expression != null) {
exp = Build(item.Expression);
} else {
throw new InvalidOperationException();
}
string alias = null;
if (item.Alias != null)
alias = item.Alias.Text;
items.Add(new SelectColumn(exp, alias));
}
return items.ToArray();
}
public override void VisitQueryExpression(SqlQueryExpressionNode node)
{
var selectColumns = GetSelectColumns(node);
var exp = new SqlQueryExpression(selectColumns);
if (node.FromClause != null) {
SetFromClause(exp.FromClause, node.FromClause);
}
if (node.WhereExpression != null) {
exp.WhereExpression = Build(node.WhereExpression);
}
if (node.GroupBy != null) {
var groupBy = new List<SqlExpression>();
if (node.GroupBy.GroupExpressions != null)
groupBy.AddRange(node.GroupBy.GroupExpressions.Select(Build));
exp.GroupBy = groupBy.ToList();
var having = node.GroupBy.HavingExpression;
if (having != null)
exp.HavingExpression = Build(having);
}
if (node.Composite != null) {
var compositeExp = Build(node.Composite.QueryExpression);
exp.NextComposite = compositeExp as SqlQueryExpression;
exp.IsCompositeAll = node.Composite.IsAll;
exp.CompositeFunction = GetCompositeFunction(node.Composite.CompositeFunction);
}
outputExpression = exp;
}
