private void Select(Resource templateSubject, Resource templatePredicate, Resource templateObject, Resource templateMeta, LiteralFilter[] litFilters, StatementSink result, int limit) {
if (result == null) throw new ArgumentNullException();
lock (syncroot) {
Init();
RunAddBuffer();
// Don't select on columns that we already know from the template.
// But grab the URIs and literal values for MultiRes selection.
SelectColumnFilter columns = new SelectColumnFilter();
columns.SubjectId = (templateSubject == null) || templateSubject is MultiRes;
columns.PredicateId = (templatePredicate == null) || templatePredicate is MultiRes;
columns.ObjectId = (templateObject == null) || templateObject is MultiRes;
columns.MetaId = (templateMeta == null) || templateMeta is MultiRes;
columns.SubjectUri = templateSubject == null;
columns.PredicateUri = templatePredicate == null;
columns.ObjectData = templateObject == null || (templateObject is MultiRes && ((MultiRes)templateObject).ContainsLiterals());
columns.MetaUri = templateMeta == null;
if (isOrContains(templatePredicate, rdfs_member)) {
columns.PredicateId = true;
columns.PredicateUri = true;
}
// Meta URIs tend to be repeated a lot, so we don't
// want to ever select them from the database.
// This preloads them, although it makes the first
// select quite slow.
/*if (templateMeta == null && SupportsSubquery) {
LoadMetaEntities();
columns.MetaUri = false;
}*/
// Have to select something
bool fakeSubjectIdSelect = false;
if (!columns.SubjectId && !columns.PredicateId && !columns.ObjectId && !columns.MetaId) {
columns.SubjectId = true;
fakeSubjectIdSelect = true;
}
// Pre-cache the IDs of resources in a MultiRes. TODO: Pool these into one array.
foreach (Resource r in new Resource[] { templateSubject, templatePredicate, templateObject, templateMeta }) {
MultiRes mr = r as MultiRes;
if (mr == null) continue;
PrefetchResourceIds(mr.items);
CleanMultiRes(mr);
if (mr.items.Length == 0) // no possible values
return;
}
// SQLite has a problem with LEFT JOIN: When a condition is made on the
// first table in the ON clause (q.objecttype=0/1), when it fails,
// it excludes the row from the first table, whereas it should only
// exclude the results of the join.
System.Text.StringBuilder cmd = new System.Text.StringBuilder("SELECT ");
if (!SupportsLimitClause && limit >= 1) {
cmd.Append("TOP ");
cmd.Append(limit);
cmd.Append(' ');
}
if (!HasUniqueStatementsConstraint)
cmd.Append("DISTINCT ");
SelectFilterColumns(columns, cmd);
cmd.Append(" FROM ");
cmd.Append(table);
cmd.Append("_statements AS q");
SelectFilterTables(columns, cmd);
cmd.Append(' ');
bool wroteWhere;
if (!WhereClause(templateSubject, templatePredicate, templateObject, templateMeta, cmd, out wroteWhere)) return;
// Transform literal filters into SQL.
if (litFilters != null) {
foreach (LiteralFilter f in litFilters) {
string s = FilterToSQL(f, "lit.value");
if (s != null) {
if (!wroteWhere) { cmd.Append(" WHERE "); wroteWhere = true; }
else { cmd.Append(" AND "); }
cmd.Append(' ');
cmd.Append(s);
}
}
}
if (SupportsLimitClause && limit >= 1) {
cmd.Append(" LIMIT ");
cmd.Append(limit);
}
cmd.Append(';');
if (Debug) {
string cmd2 = cmd.ToString();
//if (cmd2.Length > 80) cmd2 = cmd2.Substring(0, 80);
Console.Error.WriteLine(cmd2);
}
Hashtable entMap = new Hashtable();
// Be sure if a MultiRes is involved we hash the
// ids of the entities so we can return them
// without creating new ones.
CacheMultiObjects(entMap, templateSubject);
CacheMultiObjects(entMap, templatePredicate);
CacheMultiObjects(entMap, templateObject);
CacheMultiObjects(entMap, templateMeta);
using (IDataReader reader = RunReader(cmd.ToString())) {
while (reader.Read()) {
int col = 0;
Int64 sid = -1, pid = -1, ot = -1, oid = -1, mid = -1;
string suri = null, puri = null, ouri = null, muri = null;
string lv = null, ll = null, ld = null;
if (columns.SubjectId) { sid = reader.GetInt64(col++); }
if (columns.PredicateId) { pid = reader.GetInt64(col++); }
if (columns.ObjectId) { oid = reader.GetInt64(col++); }
if (columns.MetaId) { mid = reader.GetInt64(col++); }
if (columns.SubjectUri) { suri = AsString(reader[col++]); }
if (columns.PredicateUri) { puri = AsString(reader[col++]); }
if (columns.ObjectData) { ot = reader.GetInt64(col++); ouri = AsString(reader[col++]); lv = AsString(reader[col++]); ll = AsString(reader[col++]); ld = AsString(reader[col++]);}
if (columns.MetaUri) { muri = AsString(reader[col++]); }
Entity subject = GetSelectedEntity(sid, suri, templateSubject, columns.SubjectId && !fakeSubjectIdSelect, columns.SubjectUri, entMap);
Entity predicate = GetSelectedEntity(pid, puri, templatePredicate, columns.PredicateId, columns.PredicateUri, entMap);
Resource objec = GetSelectedResource(oid, ot, ouri, lv, ll, ld, templateObject, columns.ObjectId, columns.ObjectData, entMap);
Entity meta = GetSelectedEntity(mid, muri, templateMeta, columns.MetaId, columns.MetaUri, templateMeta != null ? entMap : null);
if (litFilters != null && !LiteralFilter.MatchesFilters(objec, litFilters, this))
continue;
bool ret = result.Add(new Statement(subject, predicate, objec, meta));
if (!ret) break;
}
}
} // lock
}
private void SelectFilterTables(SelectColumnFilter filter, StringBuilder cmd) {
if (filter.SubjectUri) {
cmd.Append(" LEFT JOIN ");
cmd.Append(table);
cmd.Append("_entities AS suri ON q.subject = suri.id");
}
if (filter.PredicateUri) {
cmd.Append(" LEFT JOIN ");
cmd.Append(table);
cmd.Append("_entities AS puri ON q.predicate = puri.id");
}
if (filter.ObjectData) {
cmd.Append(" LEFT JOIN ");
cmd.Append(table);
cmd.Append("_entities AS ouri ON q.object = ouri.id");
cmd.Append(" LEFT JOIN ");
cmd.Append(table);
cmd.Append("_literals AS lit ON q.object=lit.id");
}
if (filter.MetaUri) {
cmd.Append(" LEFT JOIN ");
cmd.Append(table);
cmd.Append("_entities AS muri ON q.meta = muri.id");
}
}
private void Select2(SelectFilter filter, StatementSink result)
{
// Don't select on columns that we already know from the template.
SelectColumnFilter columns = new SelectColumnFilter();
columns.Subject = (filter.Subjects == null) || (filter.Subjects.Length > 1);
columns.Predicate = (filter.Predicates == null) || (filter.Predicates.Length > 1);
columns.Object = (filter.Objects == null) || (filter.Objects.Length > 1);
columns.Meta = (filter.Metas == null) || (filter.Metas.Length > 1);;
if (filter.Predicates != null | Array.IndexOf(filter.Predicates, rdfs_member) != 1)
{
columns.Predicate = true;
}
// Have to select something
if (!columns.Subject && !columns.Predicate && !columns.Object && !columns.Meta)
{
columns.Subject = true;
}
System.Text.StringBuilder cmd = new System.Text.StringBuilder("SELECT ");
if (!connection.AreStatementsUnique)
{
cmd.Append("DISTINCT ");
}
ArrayList cols = new ArrayList();
if (columns.Subject)
{
cols.Add("sinfo.type"); cols.Add("sinfo.value");
}
if (columns.Predicate)
{
cols.Add("pinfo.type"); cols.Add("pinfo.value");
}
if (columns.Object)
{
cols.Add("oinfo.type"); cols.Add("oinfo.value"); cols.Add("oinfo.language"); cols.Add("oinfo.datatype");
}
if (columns.Meta)
{
cols.Add("minfo.type"); cols.Add("minfo.value");
}
cmd.Append(String.Join(", ", (String[])cols.ToArray(typeof(String))));
cmd.Append(" FROM ");
cmd.Append(prefix);
cmd.Append("_statements AS q");
if (columns.Subject)
{
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS sinfo ON q.subject = sinfo.id");
}
if (columns.Predicate)
{
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS pinfo ON q.predicate = pinfo.id");
}
if (columns.Object)
{
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS oinfo ON q.object = oinfo.id");
}
if (columns.Meta)
{
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS minfo ON q.meta = minfo.id");
}
cmd.Append(' ');
bool wroteWhere = WhereClause(filter, cmd);
// Transform literal filters into SQL.
if (filter.LiteralFilters != null)
{
foreach (LiteralFilter f in filter.LiteralFilters)
{
string s = FilterToSQL(f, "oinfo.value");
if (s != null)
{
if (!wroteWhere)
{
cmd.Append(" WHERE "); wroteWhere = true;
}
else
{
cmd.Append(" AND ");
}
cmd.Append(' ');
cmd.Append(s);
}
}
}
if (filter.Limit >= 1)
{
cmd.Append(" LIMIT ");
cmd.Append(filter.Limit);
}
cmd.Append(';');
if (Debug)
{
string cmd2 = cmd.ToString();
//if (cmd2.Length > 80) cmd2 = cmd2.Substring(0, 80);
Console.Error.WriteLine(cmd2);
}
using (IDataReader reader = connection.RunReader(cmd.ToString())) {
while (reader.Read())
{
Entity s = columns.Subject ? null : filter.Subjects[0];
Entity p = columns.Predicate ? null : filter.Predicates[0];
Resource o = columns.Object ? null : filter.Objects[0];
Entity m = columns.Meta ? null : filter.Metas[0];
int col = 0;
if (columns.Subject)
{
s = SelectEntity(reader.GetInt32(col++), reader.GetString(col++));
}
if (columns.Predicate)
{
p = SelectEntity(reader.GetInt32(col++), reader.GetString(col++));
}
if (columns.Object)
{
o = SelectResource(reader.GetInt32(col++), reader.GetString(col++), reader.GetString(col++), reader.GetString(col++));
}
if (columns.Meta)
{
m = SelectEntity(reader.GetInt32(col++), reader.GetString(col++));
}
if (filter.LiteralFilters != null && !LiteralFilter.MatchesFilters(o, filter.LiteralFilters, this))
{
continue;
}
bool ret = result.Add(new Statement(s, p, o, m));
if (!ret)
{
break;
}
}
}
}
private static void SelectFilterColumns(SelectColumnFilter filter, StringBuilder cmd) {
bool f = true;
if (filter.SubjectId) { cmd.Append("q.subject"); f = false; }
if (filter.PredicateId) { AppendComma(cmd, "q.predicate", !f); f = false; }
if (filter.ObjectId) { AppendComma(cmd, "q.object", !f); f = false; }
if (filter.MetaId) { AppendComma(cmd, "q.meta", !f); f = false; }
if (filter.SubjectUri) { AppendComma(cmd, "suri.value", !f); f = false; }
if (filter.PredicateUri) { AppendComma(cmd, "puri.value", !f); f = false; }
if (filter.ObjectData) { AppendComma(cmd, "q.objecttype, ouri.value, lit.value, lit.language, lit.datatype", !f); f = false; }
if (filter.MetaUri) { AppendComma(cmd, "muri.value", !f); f = false; }
}
private void Select2(SelectFilter filter, StatementSink result)
{
// Don't select on columns that we already know from the template.
SelectColumnFilter columns = new SelectColumnFilter();
columns.Subject = (filter.Subjects == null) || (filter.Subjects.Length > 1);
columns.Predicate = (filter.Predicates == null) || (filter.Predicates.Length > 1);
columns.Object = (filter.Objects == null) || (filter.Objects.Length > 1);
columns.Meta = (filter.Metas == null) || (filter.Metas.Length > 1);;
if (filter.Predicates != null | Array.IndexOf(filter.Predicates, rdfs_member) != 1)
columns.Predicate = true;
// Have to select something
if (!columns.Subject && !columns.Predicate && !columns.Object && !columns.Meta)
columns.Subject = true;
System.Text.StringBuilder cmd = new System.Text.StringBuilder("SELECT ");
if (!connection.AreStatementsUnique)
cmd.Append("DISTINCT ");
ArrayList cols = new ArrayList();
if (columns.Subject) { cols.Add("sinfo.type"); cols.Add("sinfo.value"); }
if (columns.Predicate) { cols.Add("pinfo.type"); cols.Add("pinfo.value"); }
if (columns.Object) { cols.Add("oinfo.type"); cols.Add("oinfo.value"); cols.Add("oinfo.language"); cols.Add("oinfo.datatype"); }
if (columns.Meta) { cols.Add("minfo.type"); cols.Add("minfo.value"); }
cmd.Append(String.Join(", ", (String[])cols.ToArray(typeof(String))));
cmd.Append(" FROM ");
cmd.Append(prefix);
cmd.Append("_statements AS q");
if (columns.Subject) {
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS sinfo ON q.subject = sinfo.id");
}
if (columns.Predicate) {
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS pinfo ON q.predicate = pinfo.id");
}
if (columns.Object) {
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS oinfo ON q.object = oinfo.id");
}
if (columns.Meta) {
cmd.Append(" LEFT JOIN ");
cmd.Append(prefix);
cmd.Append("_values AS minfo ON q.meta = minfo.id");
}
cmd.Append(' ');
bool wroteWhere = WhereClause(filter, cmd);
// Transform literal filters into SQL.
if (filter.LiteralFilters != null) {
foreach (LiteralFilter f in filter.LiteralFilters) {
string s = FilterToSQL(f, "oinfo.value");
if (s != null) {
if (!wroteWhere) { cmd.Append(" WHERE "); wroteWhere = true; }
else { cmd.Append(" AND "); }
cmd.Append(' ');
cmd.Append(s);
}
}
}
if (filter.Limit >= 1) {
cmd.Append(" LIMIT ");
cmd.Append(filter.Limit);
}
cmd.Append(';');
if (Debug) {
string cmd2 = cmd.ToString();
//if (cmd2.Length > 80) cmd2 = cmd2.Substring(0, 80);
Console.Error.WriteLine(cmd2);
}
using (IDataReader reader = connection.RunReader(cmd.ToString())) {
while (reader.Read()) {
Entity s = columns.Subject ? null : filter.Subjects[0];
Entity p = columns.Predicate ? null : filter.Predicates[0];
Resource o = columns.Object ? null : filter.Objects[0];
Entity m = columns.Meta ? null : filter.Metas[0];
int col = 0;
if (columns.Subject) { s = SelectEntity(reader.GetInt32(col++), reader.GetString(col++)); }
if (columns.Predicate) { p = SelectEntity(reader.GetInt32(col++), reader.GetString(col++)); }
if (columns.Object) { o = SelectResource(reader.GetInt32(col++), reader.GetString(col++), reader.GetString(col++), reader.GetString(col++)); }
if (columns.Meta) { m = SelectEntity(reader.GetInt32(col++), reader.GetString(col++)); }
if (filter.LiteralFilters != null && !LiteralFilter.MatchesFilters(o, filter.LiteralFilters, this))
continue;
bool ret = result.Add(new Statement(s, p, o, m));
if (!ret) break;
}
}
}
