public virtual void Execute(SelectStatement selectStatement)
{
// Validate top level query specifications
foreach (QuerySpecification qs in selectStatement.EnumerateQuerySpecifications())
{
ValidateQuerySpecification(qs);
}
// Validate Order By
OrderByClause orderby = selectStatement.FindDescendant<OrderByClause>();
if (orderby != null)
{
// **** TODO
}
}
public void Execute(SelectStatement selectStatement)
{
NormalizeSelectStatement(selectStatement);
}
public void NormalizeSelectStatement(SelectStatement selectStatement)
{
NormalizeQueryExpression(selectStatement.QueryExpression);
}
protected void ResolveSelectStatement(SelectStatement selectStatement, int depth)
{
// The SqlParser build the parsing tree and tags many nodes with TableReference and ColumnReference objects.
// At this point these references only contain information directly available in the query, but names are
// not verified against the database schema.
// A query consists of a set of query specifications combined using set operators (UNION, EXCEPT etc.)
// Each query specification has a FROM clause with a complex table expression. A table expression is a
// set of table sources combined with join operators. A table source can be any of the following four:
// a table (or view), a table-valued function, a table-valued variable or a subquery.
// The WHERE clause main contain additional semi-join criteria which contain subqueries.
// Steps of name resolution:
// 1. Identify all query specifications and execute name resolution on each of them
// 2. For each query specification, substitute default values if null is found
// 3. Collect column descriptions from table sources
// 4. Resolve column aliases
// 5. Resolve table aliases
// 6. Assign default column aliases
SubstituteFunctionDefaults(selectStatement);
ResolveFunctionReferences(selectStatement);
var qe = selectStatement.QueryExpression;
ResolveQueryExpression(qe, depth);
var firstqs = qe.FindDescendant<QuerySpecification>();
var orderby = selectStatement.OrderByClause;
ResolveOrderByClause(orderby, firstqs);
}
/// <summary>
/// Executes the name resolution over a query
/// </summary>
/// <param name="selectStatement"></param>
public void Execute(SelectStatement selectStatement)
{
ResolveSelectStatement(selectStatement, 0);
}
private void GetSearchCondition(string query, out SelectStatement select, out SearchCondition where)
{
var p = new SqlParser();
select = (SelectStatement)p.Execute(new SelectStatement(), query);
where = select.FindDescendantRecursive<WhereClause>().FindDescendant<SearchCondition>();
}
private void CopyMembers(SelectStatement old)
{
}
public SelectStatement(SelectStatement old)
: base(old)
{
CopyMembers(old);
}
private void InitializeMembers(StreamingContext context)
{
this.syncRoot = new object();
this.context = null;
this.scheduler = null;
this.queryFactoryTypeName = null;
this.queryFactory = new Lazy<QueryFactory>(() => (QueryFactory)Activator.CreateInstance(Type.GetType(queryFactoryTypeName)), false);
this.federationReference = new EntityProperty<Federation>();
this.queryString = null;
this.defaultDataset = null;
this.temporaryDataset = null;
this.codeDataset = null;
this.customDatasets = new List<DatasetBase>();
/*this.databaseVersionName = null;
this.defaultDatasetName = null;
this.defaultSchemaName = null;*/
this.executionMode = ExecutionMode.SingleServer;
this.isCanceled = false;
this.cancelableTasks = new Dictionary<string, ICancelableTask>();
this.assignedServerInstanceReference = new EntityProperty<ServerInstance>();
this.interpretedQueryString = null;
this.selectStatement = null;
this.temporaryDatabaseInstanceReference = new EntityProperty<DatabaseInstance>();
this.temporaryTables = new ConcurrentDictionary<string, Table>(SchemaManager.Comparer);
this.temporaryViews = new ConcurrentDictionary<string, View>(SchemaManager.Comparer);
this.codeDatabaseInstanceReference = new EntityProperty<DatabaseInstance>();
}
/// <summary>
/// Parses the query
/// </summary>
protected void Parse(bool forceReinitialize)
{
// Reparse only if needed
if (selectStatement == null || forceReinitialize)
{
var parser = queryFactory.Value.CreateParser();
selectStatement = (SelectStatement)parser.Execute(queryString);
}
}
