protected virtual IQueryPlanNode VisitSubset(SubsetNode node)
{
var child = node.Child;
if (child != null)
{
child = VisitNode(child);
}
return(new SubsetNode(child, node.OriginalColumnNames, node.AliasColumnNames));
}
private static IQueryPlanNode PlanForOrderBy(IQueryPlanNode plan, IList<SortColumn> orderBy, QueryExpressionFrom queryFrom, IList<SelectColumn> selectedColumns)
{
// Sort on the ORDER BY clause
if (orderBy.Count > 0) {
int sz = orderBy.Count;
var orderList = new ObjectName[sz];
var ascendingList = new bool[sz];
var functionOrders = new List<SqlExpression>();
for (int i = 0; i < sz; ++i) {
var column = orderBy[i];
SqlExpression exp = column.Expression;
ascendingList[i] = column.Ascending;
var v = exp.AsReferenceName();
if (v != null) {
var newV = queryFrom.ResolveReference(v);
if (newV == null)
throw new InvalidOperationException(String.Format("Could not resolve ORDER BY column '{0}' in expression", v));
newV = ReplaceAliasedVariable(newV, selectedColumns);
orderList[i] = newV;
} else {
// Otherwise we must be ordering by an expression such as
// '0 - a'.
// Resolve the expression,
exp = exp.Prepare(queryFrom.ExpressionPreparer);
// Make sure we substitute any aliased columns in the order by
// columns.
exp = ReplaceAliasedVariables(exp, selectedColumns);
// The new ordering functions are called 'FUNCTIONTABLE.#ORDER-n'
// where n is the number of the ordering expression.
orderList[i] = new ObjectName(FunctionTableName, "#ORDER-" + functionOrders.Count);
functionOrders.Add(exp);
}
}
// If there are functional orderings,
// For this we must define a new FunctionTable with the expressions,
// then order by those columns, and then use another SubsetNode
// command node.
int fsz = functionOrders.Count;
if (fsz > 0) {
var funs = new SqlExpression[fsz];
var fnames = new String[fsz];
for (int n = 0; n < fsz; ++n) {
funs[n] = functionOrders[n];
fnames[n] = "#ORDER-" + n;
}
if (plan is SubsetNode) {
// If the top plan is a SubsetNode then we use the
// information from it to create a new SubsetNode that
// doesn't include the functional orders we have attached here.
var topSubsetNode = (SubsetNode)plan;
var mappedNames = topSubsetNode.AliasColumnNames;
// Defines the sort functions
plan = new CreateFunctionsNode(plan, funs, fnames);
// Then plan the sort
plan = new SortNode(plan, orderList, ascendingList);
// Then plan the subset
plan = new SubsetNode(plan, mappedNames, mappedNames);
} else {
// Defines the sort functions
plan = new CreateFunctionsNode(plan, funs, fnames);
// Plan the sort
plan = new SortNode(plan, orderList, ascendingList);
}
} else {
// No functional orders so we only need to sort by the columns
// defined.
plan = new SortNode(plan, orderList, ascendingList);
}
}
return plan;
}
private IQueryPlanNode PlanQuery(IQueryContext context, SqlQueryExpression queryExpression,
QueryExpressionFrom queryFrom, IList<SortColumn> sortColumns)
{
// ----- Resolve the SELECT list
// If there are 0 columns selected, then we assume the result should
// show all of the columns in the result.
bool doSubsetColumn = (queryExpression.SelectColumns.Any());
// What we are selecting
var columns = BuildSelectColumns(queryExpression, queryFrom);
// Prepare the column_set,
var preparedColumns = columns.Prepare(context);
sortColumns = ResolveOrderByRefs(preparedColumns, sortColumns);
// -----
// Set up plans for each table in the from clause of the command. For
// sub-queries, we recurse.
var tablePlanner = CreateTablePlanner(context, queryFrom);
// -----
// The WHERE and HAVING clauses
var whereClause = queryExpression.WhereExpression;
var havingClause = queryExpression.HavingExpression;
PrepareJoins(tablePlanner, queryExpression, queryFrom, ref whereClause);
// Prepare the WHERE and HAVING clause, qualifies all variables and
// prepares sub-queries.
whereClause = PrepareSearchExpression(context, queryFrom, whereClause);
havingClause = PrepareSearchExpression(context, queryFrom, havingClause);
// Any extra Aggregate functions that are part of the HAVING clause that
// we need to add. This is a list of a name followed by the expression
// that contains the aggregate function.
var extraAggregateFunctions = new List<SqlExpression>();
if (havingClause != null)
havingClause = FilterHaving(havingClause, extraAggregateFunctions, context);
// Any GROUP BY functions,
ObjectName[] groupByList;
IList<SqlExpression> groupByFunctions;
var gsz = ResolveGroupBy(queryExpression, queryFrom, context, out groupByList, out groupByFunctions);
// Resolve GROUP MAX variable to a reference in this from set
var groupmaxColumn = ResolveGroupMax(queryExpression, queryFrom);
// -----
// Now all the variables should be resolved and correlated variables set
// up as appropriate.
// If nothing in the FROM clause then simply evaluate the result of the
// select
if (queryFrom.SourceCount == 0)
return EvaluateToSingle(preparedColumns);
// Plan the where clause. The returned node is the plan to evaluate the
// WHERE clause.
var node = tablePlanner.PlanSearchExpression(whereClause);
SqlExpression[] defFunList;
string[] defFunNames;
var fsz = MakeupFunctions(preparedColumns, extraAggregateFunctions, out defFunList, out defFunNames);
var groupInfo = new GroupInfo {
Columns = preparedColumns,
FunctionCount = fsz,
FunctionNames = defFunNames,
FunctionExpressions = defFunList,
GroupByCount = gsz,
GroupByNames = groupByList,
GroupByExpressions = groupByFunctions.ToArray(),
GroupMax = groupmaxColumn
};
node = PlanGroup(node, groupInfo);
// The result column list
var selectColumns = preparedColumns.SelectedColumns.ToList();
int sz = selectColumns.Count;
// Evaluate the having clause if necessary
if (havingClause != null) {
// Before we evaluate the having expression we must substitute all the
// aliased variables.
var havingExpr = havingClause;
// TODO: this requires a visitor to modify the having expression
havingExpr = ReplaceAliasedVariables(havingExpr, selectColumns);
var source = tablePlanner.SinglePlan;
source.UpdatePlan(node);
node = tablePlanner.PlanSearchExpression(havingExpr);
}
// Do we have a composite select expression to process?
IQueryPlanNode rightComposite = null;
if (queryExpression.NextComposite != null) {
var compositeExpr = queryExpression.NextComposite;
var compositeFrom = QueryExpressionFrom.Create(context, compositeExpr);
// Form the right plan
rightComposite = PlanQuery(context, compositeExpr, compositeFrom, null);
}
// Do we do a final subset column?
ObjectName[] aliases = null;
if (doSubsetColumn) {
// Make up the lists
var subsetVars = new ObjectName[sz];
aliases = new ObjectName[sz];
for (int i = 0; i < sz; ++i) {
SelectColumn scol = selectColumns[i];
subsetVars[i] = scol.InternalName;
aliases[i] = scol.ResolvedName;
}
// If we are distinct then add the DistinctNode here
if (queryExpression.Distinct)
node = new DistinctNode(node, subsetVars);
// Process the ORDER BY?
// Note that the ORDER BY has to occur before the subset call, but
// after the distinct because distinct can affect the ordering of the
// result.
if (rightComposite == null && sortColumns != null)
node = PlanForOrderBy(node, sortColumns, queryFrom, selectColumns);
// Rename the columns as specified in the SELECT
node = new SubsetNode(node, subsetVars, aliases);
} else {
// Process the ORDER BY?
if (rightComposite == null && sortColumns != null)
node = PlanForOrderBy(node, sortColumns, queryFrom, selectColumns);
}
// Do we have a composite to merge in?
if (rightComposite != null) {
// For the composite
node = new CompositeNode(node, rightComposite, queryExpression.CompositeFunction, queryExpression.IsCompositeAll);
// Final order by?
if (sortColumns != null)
node = PlanForOrderBy(node, sortColumns, queryFrom, selectColumns);
// Ensure a final subset node
if (!(node is SubsetNode) && aliases != null) {
node = new SubsetNode(node, aliases, aliases);
}
}
return node;
}
private static IQueryPlanNode PlanForOrderBy(IQueryPlanNode plan, IList <SortColumn> orderBy, QueryExpressionFrom queryFrom, IList <SelectColumn> selectedColumns)
{
// Sort on the ORDER BY clause
if (orderBy.Count > 0)
{
int sz = orderBy.Count;
var orderList = new ObjectName[sz];
var ascendingList = new bool[sz];
var functionOrders = new List <SqlExpression>();
for (int i = 0; i < sz; ++i)
{
var column = orderBy[i];
SqlExpression exp = column.Expression;
ascendingList[i] = column.Ascending;
var v = exp.AsReferenceName();
if (v != null)
{
var newV = queryFrom.ResolveReference(v);
if (newV == null)
{
throw new InvalidOperationException(String.Format("Could not resolve ORDER BY column '{0}' in expression", v));
}
newV = ReplaceAliasedVariable(newV, selectedColumns);
orderList[i] = newV;
}
else
{
// Otherwise we must be ordering by an expression such as
// '0 - a'.
// Resolve the expression,
exp = exp.Prepare(queryFrom.ExpressionPreparer);
// Make sure we substitute any aliased columns in the order by
// columns.
exp = ReplaceAliasedVariables(exp, selectedColumns);
// The new ordering functions are called 'FUNCTIONTABLE.#ORDER-n'
// where n is the number of the ordering expression.
orderList[i] = new ObjectName(FunctionTableName, "#ORDER-" + functionOrders.Count);
functionOrders.Add(exp);
}
}
// If there are functional orderings,
// For this we must define a new FunctionTable with the expressions,
// then order by those columns, and then use another SubsetNode
// command node.
int fsz = functionOrders.Count;
if (fsz > 0)
{
var funs = new SqlExpression[fsz];
var fnames = new String[fsz];
for (int n = 0; n < fsz; ++n)
{
funs[n] = functionOrders[n];
fnames[n] = "#ORDER-" + n;
}
if (plan is SubsetNode)
{
// If the top plan is a SubsetNode then we use the
// information from it to create a new SubsetNode that
// doesn't include the functional orders we have attached here.
var topSubsetNode = (SubsetNode)plan;
var mappedNames = topSubsetNode.AliasColumnNames;
// Defines the sort functions
plan = new CreateFunctionsNode(plan, funs, fnames);
// Then plan the sort
plan = new SortNode(plan, orderList, ascendingList);
// Then plan the subset
plan = new SubsetNode(plan, mappedNames, mappedNames);
}
else
{
// Defines the sort functions
plan = new CreateFunctionsNode(plan, funs, fnames);
// Plan the sort
plan = new SortNode(plan, orderList, ascendingList);
}
}
else
{
// No functional orders so we only need to sort by the columns
// defined.
plan = new SortNode(plan, orderList, ascendingList);
}
}
return(plan);
}
private IQueryPlanNode PlanQuery(IRequest context, SqlQueryExpression queryExpression,
QueryExpressionFrom queryFrom, IList <SortColumn> sortColumns, QueryLimit limit)
{
// ----- Resolve the SELECT list
// If there are 0 columns selected, then we assume the result should
// show all of the columns in the result.
bool doSubsetColumn = (queryExpression.SelectColumns.Any());
// What we are selecting
var columns = BuildSelectColumns(queryExpression, queryFrom);
// Prepare the column_set,
var preparedColumns = columns.Prepare(context);
sortColumns = ResolveOrderByRefs(preparedColumns, sortColumns);
// -----
// Set up plans for each table in the from clause of the command. For
// sub-queries, we recurse.
var tablePlanner = CreateTablePlanner(context, queryFrom);
// -----
// The WHERE and HAVING clauses
var whereClause = queryExpression.WhereExpression;
var havingClause = queryExpression.HavingExpression;
PrepareJoins(tablePlanner, queryExpression, queryFrom, ref whereClause);
// Prepare the WHERE and HAVING clause, qualifies all variables and
// prepares sub-queries.
whereClause = PrepareSearchExpression(context, queryFrom, whereClause);
havingClause = PrepareSearchExpression(context, queryFrom, havingClause);
// Any extra Aggregate functions that are part of the HAVING clause that
// we need to add. This is a list of a name followed by the expression
// that contains the aggregate function.
var extraAggregateFunctions = new List <SqlExpression>();
if (havingClause != null)
{
havingClause = FilterHaving(havingClause, extraAggregateFunctions, context);
}
// Any GROUP BY functions,
ObjectName[] groupByList;
IList <SqlExpression> groupByFunctions;
var gsz = ResolveGroupBy(queryExpression, queryFrom, context, out groupByList, out groupByFunctions);
// Resolve GROUP MAX variable to a reference in this from set
var groupmaxColumn = ResolveGroupMax(queryExpression, queryFrom);
// -----
// Now all the variables should be resolved and correlated variables set
// up as appropriate.
// If nothing in the FROM clause then simply evaluate the result of the
// select
if (queryFrom.SourceCount == 0)
{
return(EvaluateToSingle(preparedColumns));
}
// Plan the where clause. The returned node is the plan to evaluate the
// WHERE clause.
var node = tablePlanner.PlanSearchExpression(whereClause);
SqlExpression[] defFunList;
string[] defFunNames;
var fsz = MakeupFunctions(preparedColumns, extraAggregateFunctions, out defFunList, out defFunNames);
var groupInfo = new GroupInfo {
Columns = preparedColumns,
FunctionCount = fsz,
FunctionNames = defFunNames,
FunctionExpressions = defFunList,
GroupByCount = gsz,
GroupByNames = groupByList,
GroupByExpressions = groupByFunctions.ToArray(),
GroupMax = groupmaxColumn
};
node = PlanGroup(node, groupInfo);
// The result column list
var selectColumns = preparedColumns.SelectedColumns.ToList();
int sz = selectColumns.Count;
// Evaluate the having clause if necessary
if (havingClause != null)
{
// Before we evaluate the having expression we must substitute all the
// aliased variables.
var havingExpr = havingClause;
// TODO: this requires a visitor to modify the having expression
havingExpr = ReplaceAliasedVariables(havingExpr, selectColumns);
var source = tablePlanner.SinglePlan;
source.UpdatePlan(node);
node = tablePlanner.PlanSearchExpression(havingExpr);
}
// Do we have a composite select expression to process?
IQueryPlanNode rightComposite = null;
if (queryExpression.NextComposite != null)
{
var compositeExpr = queryExpression.NextComposite;
var compositeFrom = QueryExpressionFrom.Create(context, compositeExpr);
// Form the right plan
rightComposite = PlanQuery(context, compositeExpr, compositeFrom, null, null);
}
// Do we do a final subset column?
ObjectName[] aliases = null;
if (doSubsetColumn)
{
// Make up the lists
var subsetVars = new ObjectName[sz];
aliases = new ObjectName[sz];
for (int i = 0; i < sz; ++i)
{
SelectColumn scol = selectColumns[i];
subsetVars[i] = scol.InternalName;
aliases[i] = scol.ResolvedName;
}
// If we are distinct then add the DistinctNode here
if (queryExpression.Distinct)
{
node = new DistinctNode(node, subsetVars);
}
// Process the ORDER BY?
// Note that the ORDER BY has to occur before the subset call, but
// after the distinct because distinct can affect the ordering of the
// result.
if (rightComposite == null && sortColumns != null)
{
node = PlanForOrderBy(node, sortColumns, queryFrom, selectColumns);
}
// Rename the columns as specified in the SELECT
node = new SubsetNode(node, subsetVars, aliases);
}
else
{
// Process the ORDER BY?
if (rightComposite == null && sortColumns != null)
{
node = PlanForOrderBy(node, sortColumns, queryFrom, selectColumns);
}
}
// Do we have a composite to merge in?
if (rightComposite != null)
{
// For the composite
node = new CompositeNode(node, rightComposite, queryExpression.CompositeFunction, queryExpression.IsCompositeAll);
// Final order by?
if (sortColumns != null)
{
node = PlanForOrderBy(node, sortColumns, queryFrom, selectColumns);
}
// Ensure a final subset node
if (!(node is SubsetNode) && aliases != null)
{
node = new SubsetNode(node, aliases, aliases);
}
}
if (limit != null)
{
node = new LimitNode(node, limit.Offset, limit.Count);
}
return(node);
}
protected virtual IQueryPlanNode VisitSubset(SubsetNode node)
{
var child = node.Child;
if (child != null)
child = VisitNode(child);
return new SubsetNode(child, node.OriginalColumnNames, node.AliasColumnNames);
}
protected override SqlPreparedStatement PrepareStatement(IExpressionPreparer preparer, IQueryContext context)
{
var viewName = context.ResolveTableName(ViewName);
var queryFrom = QueryExpressionFrom.Create(context, QueryExpression);
var queryPlan = context.DatabaseContext().QueryPlanner().PlanQuery(context, QueryExpression, null);
var colList = ColumnNames == null ? new string[0] : ColumnNames.ToArray();
// Wrap the result around a SubsetNode to alias the columns in the
// table correctly for this view.
int sz = colList.Length;
var originalNames = queryFrom.GetResolvedColumns();
var newColumnNames = new ObjectName[originalNames.Length];
if (sz > 0) {
if (sz != originalNames.Length)
throw new InvalidOperationException("Column list is not the same size as the columns selected.");
for (int i = 0; i < sz; ++i) {
var colName = colList[i];
newColumnNames[i] = new ObjectName(viewName, colName);
}
} else {
sz = originalNames.Length;
for (int i = 0; i < sz; ++i) {
newColumnNames[i] = new ObjectName(viewName, originalNames[i].Name);
}
}
// Check there are no repeat column names in the table.
for (int i = 0; i < sz; ++i) {
var columnName = newColumnNames[i];
for (int n = i + 1; n < sz; ++n) {
if (newColumnNames[n].Equals(columnName))
throw new InvalidOperationException(String.Format("Duplicate column name '{0}' in view. A view may not contain duplicate column names.", columnName));
}
}
// Wrap the plan around a SubsetNode plan
queryPlan = new SubsetNode(queryPlan, originalNames, newColumnNames);
// We have to execute the plan to get the TableInfo that represents the
// result of the view execution.
var table = queryPlan.Evaluate(context);
var tableInfo = table.TableInfo.Alias(viewName);
return new Prepared(tableInfo, QueryExpression, queryPlan, ReplaceIfExists);
}
IStatement IPreparableStatement.Prepare(IRequest context)
{
var viewName = context.Query.ResolveTableName(ViewName);
var queryFrom = QueryExpressionFrom.Create(context, QueryExpression);
var queryPlan = context.Query.Context.QueryPlanner().PlanQuery(new QueryInfo(context, QueryExpression));
var colList = ColumnNames == null ? new string[0] : ColumnNames.ToArray();
// Wrap the result around a SubsetNode to alias the columns in the
// table correctly for this view.
int sz = colList.Length;
var originalNames = queryFrom.GetResolvedColumns();
var newColumnNames = new ObjectName[originalNames.Length];
if (sz > 0) {
if (sz != originalNames.Length)
throw new InvalidOperationException("Column list is not the same size as the columns selected.");
for (int i = 0; i < sz; ++i) {
var colName = colList[i];
newColumnNames[i] = new ObjectName(viewName, colName);
}
} else {
sz = originalNames.Length;
for (int i = 0; i < sz; ++i) {
newColumnNames[i] = new ObjectName(viewName, originalNames[i].Name);
}
}
// Check there are no repeat column names in the table.
for (int i = 0; i < sz; ++i) {
var columnName = newColumnNames[i];
for (int n = i + 1; n < sz; ++n) {
if (newColumnNames[n].Equals(columnName))
throw new InvalidOperationException(String.Format("Duplicate column name '{0}' in view. A view may not contain duplicate column names.", columnName));
}
}
// Wrap the plan around a SubsetNode plan
queryPlan = new SubsetNode(queryPlan, originalNames, newColumnNames);
return new Prepared(viewName, QueryExpression, queryPlan, ReplaceIfExists);
}
