/// <summary>
/// Collect list of table sources and load columns from the schema.
/// </summary>
/// <remarks>
/// Source tables are put into a dictionary that is keyed by table alias
/// or table name.
/// </remarks>
/// <param name="qs"></param>
private void CollectSourceTableReferences(QuerySpecification qs)
{
// --- Collect column references from subqueries or load from the database schema
foreach (var tr in qs.EnumerateSourceTableReferences(false))
{
string tablekey;
if (tr.IsSubquery || tr.IsComputed || tr.IsUdf || tr.Alias != null)
{
tablekey = tr.Alias;
}
else
{
// If no alias is used then use table name
tablekey = tr.DatabaseObjectName;
}
// Make sure that table key is used only once
if (qs.SourceTableReferences.ContainsKey(tablekey))
{
throw CreateException(ExceptionMessages.DuplicateTableAlias, null, tablekey, tr.Node);
}
else
{
var ntr = new TableReference(tr);
if (!ntr.IsSubquery && !ntr.IsComputed)
{
// Load table description from underlying schema
// Attempt to load dataset and throw exception of name cannot be resolved
DatasetBase ds;
try
{
ds = schemaManager.Datasets[ntr.DatasetName];
}
catch (KeyNotFoundException ex)
{
throw CreateException(ExceptionMessages.UnresolvableDatasetReference, ex, ntr.DatasetName, ntr.Node);
}
catch (SchemaException ex)
{
throw CreateException(ExceptionMessages.UnresolvableDatasetReference, ex, ntr.DatasetName, ntr.Node);
}
ntr.DatabaseObject = ds.GetObject(ntr.DatabaseName, ntr.SchemaName, ntr.DatabaseObjectName);
// Load column descriptions for the table
ntr.LoadColumnReferences(schemaManager);
}
qs.SourceTableReferences.Add(tablekey, ntr);
}
}
}
/// <summary>
/// Collect list of table sources and load columns from the schema.
/// </summary>
/// <remarks>
/// Source tables are put into a dictionary that is keyed by table alias
/// or table name.
/// </remarks>
/// <param name="qs"></param>
private void CollectSourceTableReferences(QuerySpecification qs)
{
// --- Collect column references from subqueries or load from the database schema
foreach (var tr in qs.EnumerateSourceTableReferences(false))
{
string tablekey;
if (tr.IsSubquery || tr.IsComputed || tr.IsUdf || tr.Alias != null)
{
tablekey = tr.Alias;
}
else
{
// If no alias is used then use table name
tablekey = tr.DatabaseObjectName;
}
// Make sure that table key is used only once
if (qs.SourceTableReferences.ContainsKey(tablekey))
{
throw CreateException(ExceptionMessages.DuplicateTableAlias, null, tablekey, tr.Node);
}
else
{
var ntr = new TableReference(tr);
if (!ntr.IsSubquery && !ntr.IsComputed)
{
// Load table description from underlying schema
// Attempt to load dataset and throw exception of name cannot be resolved
DatasetBase ds;
try
{
ds = schemaManager.Datasets[ntr.DatasetName];
}
catch (KeyNotFoundException ex)
{
throw CreateException(ExceptionMessages.UnresolvableDatasetReference, ex, ntr.DatasetName, ntr.Node);
}
catch (SchemaException ex)
{
throw CreateException(ExceptionMessages.UnresolvableDatasetReference, ex, ntr.DatasetName, ntr.Node);
}
ntr.DatabaseObject = ds.GetObject(ntr.DatabaseName, ntr.SchemaName, ntr.DatabaseObjectName);
// Load column descriptions for the table
ntr.LoadColumnReferences(schemaManager);
}
qs.SourceTableReferences.Add(tablekey, ntr);
}
}
}
