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added groupby support (actually a statical emulation thereof) for embedded database

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hns 2001-02-06 09:43:50 +00:00
parent 63e52f7f72
commit 4719197ea7
2 changed files with 75 additions and 29 deletions
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94
src/helma/objectmodel/db/Node.java
View file

@ -621,6 +621,29 @@ public class Node implements INode, Serializable {
loadNodes ();
// check if this node has a group-by subnode-relation
if (dbmap != null) {
Relation srel = dbmap.getSubnodeRelation ();
if (srel != null && srel.groupby != null) try {
Relation groupbyRel = (Relation) srel.other.db2prop.get (srel.groupby);
String groupbyProp = (groupbyRel != null) ?
groupbyRel.propname : srel.groupby;
String groupbyValue = node.getString (groupbyProp, false);
INode groupbyNode = getNode (groupbyValue, false);
// if group-by node doesn't exist, we'll create it
if (groupbyNode == null)
groupbyNode = getGroupbySubnode (groupbyValue, true);
groupbyNode.addNode (node);
checkBackLink (node);
return node;
} catch (Exception x) {
System.err.println ("Error adding groupby: "+x);
// x.printStackTrace ();
return null;
}
}
if (where < 0 || where > numberOfNodes ())
where = numberOfNodes ();
if (node.getParent () != null) {
@ -666,6 +689,15 @@ public class Node implements INode, Serializable {
}
}
checkBackLink (node);
lastmodified = System.currentTimeMillis ();
lastSubnodeChange = lastmodified;
// Server.throwNodeEvent (new NodeEvent (this, NodeEvent.SUBNODE_ADDED, node));
return node;
}
private void checkBackLink (Node node) {
// check if the subnode is in relational db and needs to link back to this
// in order to make it a subnode
if (dbmap != null) {
@ -675,18 +707,13 @@ public class Node implements INode, Serializable {
if (backlink != null && backlink.propname != null) {
if (node.get (backlink.propname, false) == null) {
if (this.state == VIRTUAL)
node.setString (backlink.propname, getParent().getID());
node.setString (backlink.propname, getNonVirtualHomeID());
else
node.setString (backlink.propname, getID());
}
}
}
}
lastmodified = System.currentTimeMillis ();
lastSubnodeChange = lastmodified;
// Server.throwNodeEvent (new NodeEvent (this, NodeEvent.SUBNODE_ADDED, node));
return node;
}
public INode createNode () {
@ -796,30 +823,43 @@ public class Node implements INode, Serializable {
return retval;
}
public Node getGroupbySubnode (String sid) {
public Node getGroupbySubnode (String sid, boolean create) {
loadNodes ();
if (subnodes.contains (sid)) try {
Node node = new Node (this, sid, nmgr, null);
// set "groupname" property to value of groupby field
node.setString ("groupname", sid);
if (subnodes == null)
subnodes = new ExternalizableVector ();
if (subnodes.contains (sid) || create) try {
Relation srel = dbmap.getSubnodeRelation ();
Relation prel = dbmap.getPropertyRelation ();
DbMapping dbm = new DbMapping ();
Relation gsrel = srel.getGroupbySubnodeRelation();
dbm.setSubnodeMapping (srel.other);
dbm.setSubnodeRelation (gsrel);
if (prel != null) {
dbm.setPropertyMapping (prel.other);
dbm.setPropertyRelation (prel.getGroupbyPropertyRelation());
boolean relational = srel.other != null && srel.other.isRelational ();
if (relational || create) {
Node node = relational ? new Node (this, sid, nmgr, null) : new Node ("groupby-"+sid, nmgr);
// set "groupname" property to value of groupby field
node.setString ("groupname", sid);
if (relational) {
DbMapping dbm = new DbMapping ();
Relation gsrel = srel.getGroupbySubnodeRelation();
dbm.setSubnodeMapping (srel.other);
dbm.setSubnodeRelation (gsrel);
if (prel != null) {
dbm.setPropertyMapping (prel.other);
dbm.setPropertyRelation (prel.getGroupbyPropertyRelation());
}
node.setDbMapping (dbm);
String snrel = "WHERE "+srel.groupby +"='"+sid+"'";
if (gsrel.direction == Relation.BACKWARD)
snrel += " AND "+gsrel.getRemoteField()+"='"+getNonVirtualHomeID()+"'";
if (gsrel.order != null)
snrel += " ORDER BY "+gsrel.order;
node.setSubnodeRelation (snrel);
} else {
subnodes.addElement (node.getID ());
setNode (sid, node);
}
return node;
}
node.setDbMapping (dbm);
String snrel = "WHERE "+srel.groupby +"='"+sid+"'";
if (gsrel.direction == Relation.BACKWARD)
snrel += " AND "+gsrel.getRemoteField()+"='"+getNonVirtualHomeID()+"'";
if (gsrel.order != null)
snrel += " ORDER BY "+gsrel.order;
node.setSubnodeRelation (snrel);
return node;
} catch (Exception noluck) {
IServer.getLogger ().log ("Error creating group-by node for "+sid+": "+noluck);
}
@ -1042,7 +1082,7 @@ public class Node implements INode, Serializable {
// return true if a change in subnodes can be ignored because it is
// stored in the subnodes themselves.
Relation rel = dbmap == null ? null : dbmap.getSubnodeRelation();
return (rel != null && rel.direction == Relation.BACKWARD);
return (rel != null && rel.other != null && rel.other.isRelational() && rel.direction == Relation.BACKWARD);
}
/**

10
src/helma/objectmodel/db/NodeManager.java
View file

@ -536,7 +536,7 @@ public final class NodeManager {
}
// set order, if specified and if not using subnode's relation
if (rel.groupby != null)
q += " GROUP BY "+rel.groupby+" ORDER BY "+rel.groupby;
q += " GROUP BY "+rel.groupby+" ORDER BY "+(rel.groupbyorder == null ? rel.groupby : rel.groupbyorder);
else if (rel.order != null)
q += " ORDER BY "+rel.order;
qds = new QueryDataSet (con, q);
@ -749,13 +749,19 @@ public final class NodeManager {
}
} else if (rel != null && rel.groupby != null) {
return home.getGroupbySubnode (kstr);
node = home.getGroupbySubnode (kstr, false);
if (node == null && (rel.other == null || !rel.other.isRelational ())) {
node = db.getNode (txn, kstr);
node.nmgr = safe;
}
return node;
} else if (rel == null || rel.other == null || !rel.other.isRelational ()) {
node = db.getNode (txn, kstr);
node.nmgr = safe;
node.setDbMapping (rel.other);
return node;
} else {
TableDataSet tds = null;
try {