public void NormalizeQuerySpecification(QuerySpecification qs)
{
foreach (var sq in qs.EnumerateSubqueries())
{
NormalizeSelectStatement(sq.SelectStatement);
}
// Process join conditions
conditions = new List <LogicalExpressions.Expression>();
var from = qs.FindDescendant <FromClause>();
if (from != null)
{
var tablesource = from.FindDescendant <TableSourceExpression>();
foreach (JoinedTable jt in tablesource.EnumerateDescendantsRecursive <JoinedTable>(typeof(Subquery)))
{
// CROSS JOIN queries have no search condition
SearchCondition sc = jt.FindDescendant <SearchCondition>();
if (sc != null)
{
conditions.Add(GetConjunctiveNormalForm(sc));
}
}
}
// Process where clause
WhereClause where = qs.FindDescendant <WhereClause>();
if (where != null)
{
var sc = where.FindDescendant <SearchCondition>();
conditions.Add(GetConjunctiveNormalForm(sc));
}
}
protected void ValidateQuerySpecification(QuerySpecification qs)
{
// Call recursively for subqueries
#if false
foreach (var sq in qs.EnumerateSubqueries())
{
ValidateQuerySpecification(sq);
}
#endif
ValidateTableReferences(qs);
ValidateStarInSelectList(qs);
// Loop through all column expressions of the select list and try to resolve them
foreach (ColumnExpression ce in qs.FindDescendant <SelectList>().EnumerateDescendants <ColumnExpression>())
{
ValidateColumnExpression(qs, ce);
}
}
/// <summary>
/// Internal routine to perform the name resolution steps on a single
/// query specification
/// </summary>
/// <param name="qs"></param>
protected void ResolveQuerySpecification(QuerySpecification qs, int depth)
{
// At this point the table and column references are all parsed
// from the query but no name resolution and cross-identification
// of these references have happened yet. After the cross-idenfication
// routine, the same tables and columns will be tagged by the
// same TableReference and ColumnReference instances.
// First of all, call everything recursively for subqueries. Subqueries
// can appear within the table sources and in the where clause semi-join
// expressions
foreach (var sq in qs.EnumerateSubqueries())
{
ResolveSelectStatement(sq.SelectStatement, depth + 1);
}
// Substitute default dataset names and schema names
// This is typically the MYDB and dbo
SubstituteTableAndColumnDefaults(qs);
// Column references will be stored under the query specification
CollectSourceTableReferences(qs);
// Column identifiers can contain table names, aliases or nothing,
// resolve them now
ResolveTableReferences(qs);
// Substitute SELECT * expressions
SubstituteStars(qs);
// Resolve column references of each occurance
ResolveColumnReferences(qs);
// Copy resultset columns to the appropriate collection
CopyResultsColumns(qs);
// Add default aliases to column expressions in the form of tablealias_columnname
if (depth == 0)
{
AssignDefaultColumnAliases(qs);
}
}
public void NormalizeQuerySpecification(QuerySpecification qs)
{
foreach (var sq in qs.EnumerateSubqueries())
{
NormalizeSelectStatement(sq.SelectStatement);
}
// Process join conditions
conditions = new List<LogicalExpressions.Expression>();
var from = qs.FindDescendant<FromClause>();
if (from != null)
{
var tablesource = from.FindDescendant<TableSourceExpression>();
foreach (JoinedTable jt in tablesource.EnumerateDescendantsRecursive<JoinedTable>(typeof(Subquery)))
{
// CROSS JOIN queries have no search condition
SearchCondition sc = jt.FindDescendant<SearchCondition>();
if (sc != null)
{
conditions.Add(GetConjunctiveNormalForm(sc));
}
}
}
// Process where clause
WhereClause where = qs.FindDescendant<WhereClause>();
if (where != null)
{
var sc = where.FindDescendant<SearchCondition>();
conditions.Add(GetConjunctiveNormalForm(sc));
}
}
/// <summary>
/// Internal routine to perform the name resolution steps on a single
/// query specification
/// </summary>
/// <param name="qs"></param>
protected void ResolveQuerySpecification(QuerySpecification qs, int depth)
{
// At this point the table and column references are all parsed
// from the query but no name resolution and cross-identification
// of these references have happened yet. After the cross-idenfication
// routine, the same tables and columns will be tagged by the
// same TableReference and ColumnReference instances.
// First of all, call everything recursively for subqueries. Subqueries
// can appear within the table sources and in the where clause semi-join
// expressions
foreach (var sq in qs.EnumerateSubqueries())
{
ResolveSelectStatement(sq.SelectStatement, depth + 1);
}
// Substitute default dataset names and schema names
// This is typically the MYDB and dbo
SubstituteDefaults(qs);
// Column references will be stored under the query specification
CollectSourceTableReferences(qs);
// Column identifiers can contain table names, aliases or nothing,
// resolve them now
ResolveTableReferences(qs);
// Substitute SELECT * expressions
SubstituteStars(qs);
// Resolve column references of each occurance
ResolveColumnReferences(qs);
// Copy resultset columns to the appropriate collection
CopyResultsColumns(qs);
// Add default aliases to column expressions in the form of tablealias_columnname
if (depth == 0)
{
AssignDefaultColumnAliases(qs);
}
}
protected void ValidateQuerySpecification(QuerySpecification qs)
{
// Call recursively for subqueries
#if false
foreach (var sq in qs.EnumerateSubqueries())
{
ValidateQuerySpecification(sq);
}
#endif
ValidateTableReferences(qs);
ValidateStarInSelectList(qs);
// Loop through all column expressions of the select list and try to resolve them
foreach (ColumnExpression ce in qs.FindDescendant<SelectList>().EnumerateDescendants<ColumnExpression>())
{
ValidateColumnExpression(qs, ce);
}
}
