public QueryResult Execute(Session session, PreparedQuery preparedQuery)
{
if (preparedQuery.QueryType == Constants.QueryType.Select)
{
return(core.Documents.ExecuteSelect(session, preparedQuery));
}
throw new LeafSQLExecutionException("The query type has not been implemented.");
}
static public PreparedQuery ParseQuery(string query)
{
PreparedQuery result = new PreparedQuery();
Utilities.CleanQueryText(ref query);
Dictionary <string, string> literalStrings = Utilities.SwapOutLiteralStrings(ref query);
int position = 0;
string token = string.Empty;
token = Utilities.GetNextToken(query, ref position);
QueryType queryType = QueryType.Select;
if (Enum.TryParse <QueryType>(token, true, out queryType) == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected select, insert, update or delete.");
}
result.QueryType = queryType;
//--------------------------------------------------------------------------------------------------------------------------------------------
if (queryType == QueryType.Delete)
{
token = Utilities.GetNextToken(query, ref position);
if (token.ToLower() == "top")
{
token = Utilities.GetNextToken(query, ref position);
int rowLimit = 0;
if (Int32.TryParse(token, out rowLimit) == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected numeric row limit.");
}
result.RowLimit = rowLimit;
//Get schema name:
token = Utilities.GetNextToken(query, ref position);
}
if (token == string.Empty || Utilities.IsValidIdentifier(token, "/\\") == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected schema name.");
}
result.Schema = token;
token = Utilities.GetNextToken(query, ref position);
if (token.ToLower() == "where")
{
string conditionText = query.Substring(position).Trim();
if (conditionText == string.Empty)
{
throw new Exception("Invalid query. Found [" + token + "], expected list of conditions.");
}
result.Conditions = ParseConditions(conditionText);
}
else if (token != string.Empty)
{
throw new Exception("Invalid query. Found [" + token + "], expected end of statement.");
}
}
//--------------------------------------------------------------------------------------------------------------------------------------------
else if (queryType == QueryType.Update)
{
token = Utilities.GetNextToken(query, ref position);
if (token.ToLower() == "top")
{
token = Utilities.GetNextToken(query, ref position);
int rowLimit = 0;
if (Int32.TryParse(token, out rowLimit) == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected numeric row limit.");
}
result.RowLimit = rowLimit;
//Get schema name:
token = Utilities.GetNextToken(query, ref position);
}
if (token == string.Empty || Utilities.IsValidIdentifier(token, "/\\") == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected schema name.");
}
result.Schema = token;
token = Utilities.GetNextToken(query, ref position);
if (token.ToLower() != "set")
{
throw new Exception("Invalid query. Found [" + token + "], expected [SET].");
}
result.UpsertKeyValuePairs = ParseUpsertKeyValues(query, ref position);
token = Utilities.GetNextToken(query, ref position);
if (token != string.Empty && token.ToLower() != "where")
{
throw new Exception("Invalid query. Found [" + token + "], expected [WHERE] or end of statement.");
}
if (token.ToLower() == "where")
{
string conditionText = query.Substring(position).Trim();
if (conditionText == string.Empty)
{
throw new Exception("Invalid query. Found [" + token + "], expected list of conditions.");
}
result.Conditions = ParseConditions(conditionText);
}
else if (token != string.Empty)
{
throw new Exception("Invalid query. Found [" + token + "], expected end of statement.");
}
}
//--------------------------------------------------------------------------------------------------------------------------------------------
else if (queryType == QueryType.Select)
{
token = Utilities.GetNextToken(query, ref position);
if (token.ToLower() == "top")
{
token = Utilities.GetNextToken(query, ref position);
int rowLimit = 0;
if (Int32.TryParse(token, out rowLimit) == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected numeric row limit.");
}
result.RowLimit = rowLimit;
token = Utilities.GetNextToken(query, ref position); //Select the first column name for the loop below.
}
while (true)
{
if (token.ToLower() == "from" || token == string.Empty)
{
break;
}
if (Utilities.IsValidIdentifier(token) == false && token != "*")
{
throw new Exception("Invalid token. Found [" + token + "] a valid identifier.");
}
result.SelectFields.Add(token);
token = Utilities.GetNextToken(query, ref position);
}
if (token.ToLower() != "from")
{
throw new Exception("Invalid query. Found [" + token + "], expected [FROM].");
}
token = Utilities.GetNextToken(query, ref position);
if (token == string.Empty || Utilities.IsValidIdentifier(token, ":") == false)
{
throw new Exception("Invalid query. Found [" + token + "], expected schema name.");
}
result.Schema = token;
token = Utilities.GetNextToken(query, ref position);
if (token != string.Empty && token.ToLower() != "where")
{
throw new Exception("Invalid query. Found [" + token + "], expected [WHERE] or end of statement.");
}
if (token.ToLower() == "where")
{
string conditionText = query.Substring(position).Trim();
if (conditionText == string.Empty)
{
throw new Exception("Invalid query. Found [" + token + "], expected list of conditions.");
}
result.Conditions = ParseConditions(conditionText);
}
else if (token != string.Empty)
{
throw new Exception("Invalid query. Found [" + token + "], expected end of statement.");
}
}
//--------------------------------------------------------------------------------------------------------------------------------------------
foreach (var literalString in literalStrings)
{
if (result.Conditions != null)
{
foreach (var kvp in result.Conditions.Flattened)
{
kvp.Key = kvp.Key.Replace(literalString.Key, literalString.Value);
kvp.Value = kvp.Value.Replace(literalString.Key, literalString.Value);
}
}
if (result.UpsertKeyValuePairs != null)
{
foreach (var kvp in result.UpsertKeyValuePairs.Collection)
{
kvp.Key = kvp.Key.Replace(literalString.Key, literalString.Value);
kvp.Value = kvp.Value.Replace(literalString.Key, literalString.Value);
}
}
}
if (result.Conditions != null)
{
foreach (var kvp in result.Conditions.Flattened)
{
if (kvp.Key.StartsWith("\'") && kvp.Key.EndsWith("\'"))
{
kvp.Key = kvp.Key.Substring(1, kvp.Key.Length - 2);
kvp.IsKeyConstant = true;
}
if (kvp.Value.StartsWith("\'") && kvp.Value.EndsWith("\'"))
{
kvp.Value = kvp.Value.Substring(1, kvp.Value.Length - 2);
kvp.IsValueConstant = true;
}
//Process escape sequences:
kvp.Key = kvp.Key.Replace("\\'", "\'");
kvp.Value = kvp.Value.Replace("\\'", "\'");
if (kvp.Key.All(Char.IsDigit))
{
kvp.IsKeyConstant = true;
}
if (kvp.Value.All(Char.IsDigit))
{
kvp.IsValueConstant = true;
}
}
}
if (result.UpsertKeyValuePairs != null)
{
foreach (var kvp in result.UpsertKeyValuePairs.Collection)
{
if (kvp.Key.StartsWith("\'") && kvp.Key.EndsWith("\'"))
{
kvp.Key = kvp.Key.Substring(1, kvp.Key.Length - 2);
kvp.IsKeyConstant = true;
}
if (kvp.Value.StartsWith("\'") && kvp.Value.EndsWith("\'"))
{
kvp.Value = kvp.Value.Substring(1, kvp.Value.Length - 2);
kvp.IsValueConstant = true;
}
//Process escape sequences:
kvp.Key = kvp.Key.Replace("\\'", "\'");
kvp.Value = kvp.Value.Replace("\\'", "\'");
if (kvp.Key.All(Char.IsDigit))
{
kvp.IsKeyConstant = true;
}
if (kvp.Value.All(Char.IsDigit))
{
kvp.IsValueConstant = true;
}
}
}
result.Conditions.MakeLowerCase();
return(result);
}
