public async ValueTask <object> ExecuteScalar(string sql, SqlParameters parameters = null, object data = null)
{
sql = OffsetLimitUtils.TransformQuery(sql);
var tree = _sqlParser.Parse(sql);
var mainVisitor = new MainVisitor(new VisitorMetadata(parameters, _tablesMetadata, _searchExpressionProvider, _operationsProvider));
tree.Accept(mainVisitor);
//Convert into execute stages
var executeStages = _stageConverter.Convert(mainVisitor.Stages);
var result = await _queryExecutor.Execute(executeStages, data);
var enumerator = result.Result.GetEnumerator();
if (!enumerator.MoveNext())
{
return(null);
}
else
{
var obj = enumerator.Current;
return(AnonTypeUtils.GetDelegates(obj.GetType())[0](obj));
}
}
private IReadOnlyList <IQueryStage> GetStages(StatementList tree, SqlParameters parameters)
{
var mainVisitor = new MainVisitor(new VisitorMetadata(parameters, _tablesMetadata, _searchExpressionProvider, _operationsProvider));
tree.Accept(mainVisitor);
return(mainVisitor.Stages);
}
static void Main(string[] args)
{
var fstream = new FileStream(args [0], FileMode.Open);
var foutstream = new StreamWriter(args [1]);
var input = new AntlrInputStream(fstream);
var lexer = new graLexer(input);
var tokens = new CommonTokenStream(lexer);
var parser = new graParser(tokens);
MainVisitor vis = new MainVisitor();
List <String> code = (List <String>)vis.VisitProgram(parser.program());
foreach (String s in code)
{
foutstream.Write(s);
foutstream.Write(Environment.NewLine);
}
foutstream.Close();
//Console.Read();
}
private IReadOnlyList <IQueryStage> GetStages(string sql, SqlParameters parameters)
{
if (string.IsNullOrEmpty(sql))
{
throw new SqlErrorException("Empty query string");
}
var tree = _sqlParser.Parse(sql, out var errors);
if (errors.Count > 0)
{
var firstError = errors.FirstOrDefault();
throw new SqlErrorException(firstError.Message);
}
var mainVisitor = new MainVisitor(new VisitorMetadata(parameters, _tablesMetadata, _searchExpressionProvider, _operationsProvider));
tree.Accept(mainVisitor);
return(mainVisitor.Stages);
}
public override void VisitFromClause(FromClause fromClause)
{
var tableReference = fromClause.TableReference;
if (tableReference is FromTableReference namedTableReference)
{
var tableName = namedTableReference.TableName;
Debug.Assert(tableName != null);
if (!_visitorMetadata.TablesMetadata.TryGetTable(tableName, out _table))
{
throw new SqlErrorException($"The table '{tableName}' was not found");
}
//Add the table name to the aliases as well, to support using the tablename infront of columns
FromAliases.AddAlias(tableName);
var alias = namedTableReference?.Alias;
if (alias != null)
{
FromAliases.AddAlias(alias);
}
}
else if (tableReference is Subquery queryDerivedTable)
{
MainVisitor mainVisitor = new MainVisitor(_visitorMetadata);
queryDerivedTable.Accept(mainVisitor);
Stages = mainVisitor.Stages;
var alias = queryDerivedTable?.Alias;
if (alias != null)
{
FromAliases.AddAlias(alias);
}
}
else
{
throw new SqlErrorException("Subqueries or joins are not supported at this time");
}
}
public MainParser(MainVisitor mainVisitor)
{
_mainVisitor = mainVisitor;
}
