public override void Retract (Term Term, VarStack stack, Term where)
{
StringBuilder deleteStat = new StringBuilder ("DELETE FROM " + dbEntity);
TableColumnCollection tcc = (TableColumnCollection)MetaDataCollection;
ListDictionary varNrs = new ListDictionary ();
bool first = true;
for (int i = 0; i < Term.Arity; i++)
{
Term arg = Term.Arg (i);
string colName = tcc [i].Name;
if (arg.IsAtom || arg.IsString)
deleteStat.AppendFormat ("{0} {1}={2}", Conj (ref first), colName, Utils.EnsureQuoted (arg.Functor));
else if (arg.IsNumber)
deleteStat.AppendFormat ("{0} {1}={2}", Conj (ref first), colName, arg.Functor);
else if (arg.IsVar)
{
object prevColNo;
// check whether value occurred as argument before (anonymous vars always have a unique varNo)
if ((prevColNo = varNrs [arg.VarNo]) != null) // ... yes
deleteStat.AppendFormat ("{0} {1}={2}", Conj (ref first), tcc [(int)prevColNo].Name, colName);
varNrs [arg.VarNo] = i; // save for comparison with next argument(s)
}
else if (!arg.IsVar)
IO.Error ("Illegal argument {0} for retract of persistent clause {1}", arg, Term);
}
if (where != null) // add the extra where-clause (if any)
{
// Copy the ref-table of column numers into a ref-table of corresponding column names
ListDictionary varNames = new ListDictionary (); // ... in-situ modifications of Collection-values is not possible
foreach (DictionaryEntry de in varNrs) varNames [(int)de.Key] = tcc [(int)de.Value].Name;
deleteStat.AppendFormat ("{0} {1}", Conj (ref first), where.ToStringSql (varNames));
}
if (first)
IO.Warning ("Retract -- DELETE without WHERE -- will NOT be executed !!!!!!!!");
else
ExecuteSqlCommand (deleteStat.ToString ());
}
protected ClauseNode GetSelectablePersistentData (Term t, Term where)
{
ListDictionary varNrs = new ListDictionary ();
ProcParamCollection ppc = (ProcParamCollection)MetaDataCollection;
bool first;
int varNo;
if (ppc.Count != t.Arity)
IO.Error ("Number of parameters ({0}) for stored procedure '{1}' does not match the arity of persistent predicate {2}/{3}",
ppc.Count, dbEntity, name, arity);
// get all arguments from t and construct the corresponding SELECT-statement.
// The arguments must be either atomic or var, but may not be compound (apart from date(...))
StringBuilder fetchStat = new StringBuilder ("SELECT NULL");
for (int i = inputParamCount; i < ppc.Count; i++) fetchStat.AppendFormat (", {0}", ppc [i].Name); // output parameters only
fetchStat.Append (" FROM ");
int keyStart = fetchStat.Length; // Dataset key, to test whether the query result has already been executed before
fetchStat.Append (dbEntity);
// append stored procedure input parameters (if any)
if (inputParamCount > 0)
{
fetchStat.Append (" (");
varNo = 0;
first = true;
for (int i = 0; i < inputParamCount; i++)
{
if (first) first = false; else fetchStat.Append (", ");
Term tt = t.Arg (varNo++);
if (tt.IsAtom || tt.IsString)
fetchStat.Append ("'" + tt.Functor + "'");
else if (tt.IsNumber)
fetchStat.Append (tt.Functor);
else
IO.Error ("Illegal stored procedure input parameter {0} in persistent term {1}", tt, t);
}
fetchStat.Append (")");
}
// construct a condition in a where-clause for each instantiated (output) argument of t
varNo = 0; // t.Arg (0) is first output parameter (if any)
first = true;
for (int colNo = inputParamCount; colNo < ppc.Count; colNo++)
{
string colName = ppc [colNo].Name;
Term tt = t.Arg (varNo);
if (tt.IsVar)
{
object prevColNo;
// check whether value occurred as argument before (anonymous vars always have a unique varNo)
if ((prevColNo = varNrs [tt.VarNo]) != null) // ... yes
fetchStat.AppendFormat ("{0} {1}={2}", Conj (ref first), ppc [(int)prevColNo].Name, colName);
varNrs [tt.VarNo] = colNo; // save for comparison with next argument(s)
}
else if (!(tt.IsAtom || tt.IsString || tt.IsNumber))
IO.Error ("Illegal argument {0} in persistent term {1}", tt, t);
varNo++;
}
// add the extra where-clause (if any)
if (where != null)
{
// Copy the ref-table of column numers into a ref-table of corresponding column names
ListDictionary varNames = new ListDictionary (); // ... in-situ modifications of Collection-values is not possible
foreach (DictionaryEntry de in varNrs)
varNames [(int)de.Key] = ppc [(int)de.Value].Name;
fetchStat.AppendFormat ("{0} {1}", Conj (ref first), where.ToStringSql (varNames));
}
fetchStat.Append (";");
//Console.WriteLine ("ProcedurePredDescr.GetPersistentData -- fetchStat = \"{0}\"", fetchStat);
DataRowCollection drc = GetResultsetForSelect (fetchStat.ToString (), keyStart); // get the data
return (drc == null || drc.Count == 0) ? null : new PersistentClauseNode (drc, 0, this);
}
protected override ClauseNode GetPersistentData (Term t, Term where)
{
query = t;
ListDictionary varNrs = new ListDictionary ();
TableColumnCollection tcc = (TableColumnCollection)MetaDataCollection;
if (tcc.Count != t.Arity)
IO.Error ("Number of columns ({0}) in table/view '{1}' does not match the arity of persistent predicate {2}/{3}",
tcc.Count, dbEntity, name, arity);
// get all output arguments from t and construct the corresponding SELECT-statement.
StringBuilder fetchStat = new StringBuilder ("SELECT NULL");
for (int i = 0; i < tcc.Count; i++)
if (t.Args [i].IsVar) fetchStat.AppendFormat (", {0}", tcc [i].Name);
fetchStat.Append (" FROM ");
int keyStart = fetchStat.Length; // Dataset key, to test whether the query result has already been executed before
fetchStat.Append (dbEntity);
int colNo = 0;
bool first = true;
// construct a condition in a where-clause for each instantiated argument of t
foreach (Term tt in t.Args)
{
string colName = tcc [colNo].Name;
if (tt.IsAtom || tt.IsString)
fetchStat.AppendFormat ("{0} {1}={2}", Conj (ref first), colName, Utils.EnsureQuoted (tt.Functor));
else if (tt.IsNumber)
fetchStat.AppendFormat ("{0} {1}={2}", Conj (ref first), colName, tt.Functor);
else if (tt.IsVar)
{
object prevColNo;
// check whether value occurred as argument before (anonymous vars always have a unique varNo)
if ((prevColNo = varNrs [tt.VarNo]) != null) // ... yes
fetchStat.AppendFormat ("{0} {1}={2}", Conj (ref first), tcc [(int)prevColNo].Name, colName);
varNrs [tt.VarNo] = colNo; // save for comparison with next argument(s)
}
else
IO.Error ("Illegal argument {0} in persistent term {1}", tt, t);
colNo++;
}
if (where != null) // add the extra where-clause
{
// Copy the ref-table of column numers into a ref-table of corresponding column names
ListDictionary varNames = new ListDictionary (); // ... in-situ modifications of Collection-values is not possible
foreach (DictionaryEntry de in varNrs)
varNames [(int)de.Key] = tcc [(int)de.Value].Name;
fetchStat.AppendFormat ("{0} {1}", Conj (ref first), where.ToStringSql (varNames));
}
fetchStat.Append (";");
//Console.WriteLine ("TablePredDescr.GetPersistentData -- fetchStat = \"{0}\"", fetchStat);
DataRowCollection drc = GetResultsetForSelect (fetchStat.ToString (), keyStart); // get the data
return (drc == null || drc.Count == 0) ? null : new PersistentClauseNode (drc, 0, this);
}
