public static SqlQueryExpression Form(IContext context, PlSqlParser.SubqueryContext subquery,
out SqlParseIntoClause into)
{
var query = Form(context, subquery.subqueryBasicElements(), out @into);
var opPart = subquery.subquery_operation_part();
if (opPart.Length > 0)
{
if (@into != null)
{
throw new InvalidOperationException("Cannot SELECT INTO in a composite query.");
}
foreach (var part in opPart)
{
CompositeFunction function;
if (part.MINUS() != null || part.EXCEPT() != null)
{
function = CompositeFunction.Except;
}
else if (part.UNION() != null)
{
function = CompositeFunction.Union;
}
else if (part.INTERSECT() != null)
{
function = CompositeFunction.Intersect;
}
else
{
throw new ParseCanceledException("Invalid composite function.");
}
bool isAll = part.ALL() != null;
var next = Form(context, part.subqueryBasicElements());
var prev = query.NextComposite;
if (prev == null)
{
prev = new SqlQueryExpressionComposite(function, isAll, next);
}
else
{
prev.Expression.NextComposite = new SqlQueryExpressionComposite(function, isAll, next);
}
query.NextComposite = prev;
}
}
return(query);
}
private static SqlQueryExpression Form(IContext context,
PlSqlParser.SubqueryBasicElementsContext basicElements, out SqlParseIntoClause into)
{
var sub = basicElements.subquery();
if (sub != null && !sub.IsEmpty)
{
return(Form(context, sub, out @into));
}
return(Form(context, basicElements.queryBlock(), out @into));
}
private static SqlQueryExpression Form(IContext context, PlSqlParser.QueryBlockContext queryBlock,
out SqlParseIntoClause into)
{
var fromClause = FromClauseBuilder.Build(context, queryBlock.fromClause());
SqlQueryExpressionItem[] columns;
if (queryBlock.all != null)
{
columns = new[] { new SqlQueryExpressionItem(SqlExpression.Reference(new ObjectName("*"))) };
}
else
{
columns = queryBlock.selectedElement().Select(x => SelectElement.BuildColumn(context, x)).ToArray();
}
var query = new SqlQueryExpression();
foreach (var column in columns)
{
query.Items.Add(column);
}
@into = null;
if (queryBlock.DISTINCT() != null ||
queryBlock.UNIQUE() != null)
{
query.Distinct = true;
}
var intoClause = queryBlock.into_clause();
if (intoClause != null)
{
@into = new SqlParseIntoClause();
if (intoClause.objectName() != null)
{
@into.TableName = SqlParseUtil.Name.Object(intoClause.objectName());
}
else if (intoClause.variable_name() != null)
{
@into.Variables = intoClause.variable_name().Select(Name.Variable).ToArray();
}
}
if (fromClause != null)
{
query.From = fromClause;
}
var groupBy = queryBlock.groupByClause();
if (groupBy != null && !groupBy.IsEmpty)
{
query.GroupBy = groupBy.groupByElements().expression()
.Select(x => new PlSqlExpressionVisitor(context).Visit(x)).ToList();
var having = groupBy.havingClause();
if (having != null)
{
query.Having = new PlSqlExpressionVisitor(context).Visit(having.condition());
}
}
var groupMax = queryBlock.groupMaxClause();
if (groupMax != null && !groupMax.IsEmpty)
{
var maxColumn = Name.Object(groupMax.objectName());
query.GroupMax = maxColumn;
}
var whereClause = queryBlock.whereClause();
if (whereClause != null && !whereClause.IsEmpty)
{
var currentOf = whereClause.current_of_clause();
if (currentOf != null && !currentOf.IsEmpty)
{
var cursorName = Name.Simple(currentOf.cursor_name());
throw new NotImplementedException();
}
else
{
query.Where = new PlSqlExpressionVisitor(context).Visit(whereClause.conditionWrapper());
}
}
//TODO: in case of a SELECT INTO cause create a statement
return(query);
}