From b8cf9b2e4cdfe65cf007893c2a94758e03e6864a Mon Sep 17 00:00:00 2001
From: hns <hannesw@gmail.com>
Date: Wed, 20 Nov 2002 19:31:31 +0000
Subject: [PATCH] Fetch database records in natural order

---
 src/helma/objectmodel/db/DbMapping.java   | 45 +++++++++++++----------
 src/helma/objectmodel/db/Node.java        | 12 +++---
 src/helma/objectmodel/db/NodeManager.java | 24 +++++++-----
 3 files changed, 45 insertions(+), 36 deletions(-)

diff --git a/src/helma/objectmodel/db/DbMapping.java b/src/helma/objectmodel/db/DbMapping.java
index 0369f39d..f89347eb 100644
--- a/src/helma/objectmodel/db/DbMapping.java
+++ b/src/helma/objectmodel/db/DbMapping.java
@@ -52,8 +52,8 @@ public final class DbMapping implements Updatable {
     HashMap prop2db;
      // Map of db columns to Relations objects
     HashMap db2prop;
-    // prerendered list of columns to fetch from db
-    String columns = null;
+    // list of columns to fetch from db
+    String[] columns = null;
     // pre-rendered select statement
     String select = null;
 
@@ -139,8 +139,6 @@ public final class DbMapping implements Updatable {
      * for rewire to work, all other db mappings must have been initialized and registered.
      */
     public synchronized void update () {
-	// reset columns
-	columns = select = null;
 	// read in properties
 	table = props.getProperty ("_table");
 	idgen = props.getProperty ("_idgen");
@@ -184,9 +182,13 @@ public final class DbMapping implements Updatable {
 	}
 
 	lastTypeChange = props.lastModified ();
-	// set the cached schema & keydef to null so it's rebuilt the next time around
+	// null the cached schema & keydef so it's rebuilt the next time around
 	schema = null;
 	keydef = null;
+	// same with columns and select string
+	columns = null;
+	select = null;
+
 
 	if (extendsProto != null) {
 	    parentMapping = app.getDbMapping (extendsProto);
@@ -574,12 +576,12 @@ public final class DbMapping implements Updatable {
     /**
      * Return a Village Schema object for this DbMapping.
      */
-    public synchronized String getColumns() throws ClassNotFoundException, SQLException {
+    public synchronized String[] getColumns() throws ClassNotFoundException, SQLException {
 	if (!isRelational ())
 	    throw new SQLException ("Can't get Schema for non-relational data mapping");
 	if (source == null && parentMapping != null)
 	    return parentMapping.getColumns ();
-	// Use local variable s to avoid synchronization (schema may be nulled elsewhere)
+	// Use local variable cols to avoid synchronization (schema may be nulled elsewhere)
 	if (columns == null) {
 	    // we do two things here: set the SQL type on the Relation mappings
 	    // and build a string of column names.
@@ -590,18 +592,16 @@ public final class DbMapping implements Updatable {
 	        throw new SQLException ("Error retrieving DB scheme for "+this);
 	    ResultSetMetaData meta = rs.getMetaData ();
 	    // ok, we have the meta data, now loop through mapping...
-	    // StringBuffer cbuffer = new StringBuffer (getIDField ());
-	    for (Iterator i=getDBPropertyIterator(); i.hasNext(); ) {
-	        Relation rel = (Relation) i.next ();
-	        if (rel.reftype != Relation.PRIMITIVE && rel.reftype != Relation.REFERENCE)
+	    int ncols = meta.getColumnCount ();
+	    columns = new String[ncols];
+	    for (int i=0; i<ncols; i++) {
+	        columns[i] = meta.getColumnName (i+1);
+	        Relation rel = columnNameToRelation (columns[i]);
+	        if (rel == null || (rel.reftype != Relation.PRIMITIVE &&
+	                            rel.reftype != Relation.REFERENCE))
 	            continue;
-	        // cbuffer.append (",");
-	        // cbuffer.append (rel.getDbField());
-	        int idx = rs.findColumn (rel.getDbField());
-	        rel.setColumnType (meta.getColumnType (idx));
+	        rel.setColumnType (meta.getColumnType (i+1));
 	    }
-	    // columns = cbuffer.toString();
-	    columns = "*";
 	}
 	return columns;
     }
@@ -610,9 +610,14 @@ public final class DbMapping implements Updatable {
 	String sel = select;
 	if (sel != null)
 	    return new StringBuffer (sel);
-	StringBuffer s = new StringBuffer ("select ");
-	s.append (getColumns ());
-	s.append (" from ");
+	StringBuffer s = new StringBuffer ("SELECT * FROM ");
+	/* String[] cols = getColumns ();
+	for (int i=0; i<cols.length; i++) {
+	    if (i>0)
+	        s.append (",");
+	    s.append (cols[i]);
+	}
+	s.append (" FROM "); */
 	s.append (getTableName ());
 	s.append (" ");
 	// cache rendered string for later calls.
diff --git a/src/helma/objectmodel/db/Node.java b/src/helma/objectmodel/db/Node.java
index 4feaf3d2..dba3415d 100644
--- a/src/helma/objectmodel/db/Node.java
+++ b/src/helma/objectmodel/db/Node.java
@@ -235,7 +235,8 @@ public final class Node implements INode, Serializable {
     /**
      * Constructor used for nodes being stored in a relational database table.
      */
-    public Node (DbMapping dbm, ResultSet rs, WrappedNodeManager nmgr) throws SQLException {
+    public Node (DbMapping dbm, ResultSet rs, String[] columns, WrappedNodeManager nmgr)
+                 throws SQLException {
 
 	this.nmgr = nmgr;
 	// see what prototype/DbMapping this object should use
@@ -268,12 +269,11 @@ public final class Node implements INode, Serializable {
 
 	created = lastmodified = System.currentTimeMillis ();
 
-	for (Iterator i=dbmap.getDBPropertyIterator(); i.hasNext(); ) {
+	for (int i=0; i<columns.length; i++) {
 
-	    Relation rel = (Relation) i.next ();
-	    // NOTE: this should never be the case, since we're just looping through
-	    // mappnigs with a local db column
-	    if (rel.reftype != Relation.PRIMITIVE && rel.reftype != Relation.REFERENCE)
+	    Relation rel = dbm.columnNameToRelation (columns[i]);
+	    if (rel == null || (rel.reftype != Relation.PRIMITIVE &&
+	                        rel.reftype != Relation.REFERENCE))
 	        continue;
 
 	    Property newprop = new Property (rel.propName, this);
diff --git a/src/helma/objectmodel/db/NodeManager.java b/src/helma/objectmodel/db/NodeManager.java
index eace5848..f11b628d 100644
--- a/src/helma/objectmodel/db/NodeManager.java
+++ b/src/helma/objectmodel/db/NodeManager.java
@@ -750,6 +750,7 @@ public final class NodeManager {
 
 	    Connection con = dbm.getConnection ();
 	    Statement stmt = con.createStatement ();
+	    String[] columns = dbm.getColumns ();
 	    StringBuffer q = dbm.getSelect ();
 	    try {
 	        if (home.getSubnodeRelation() != null) {
@@ -771,7 +772,7 @@ public final class NodeManager {
 
 	        while (rs.next()) {
 	            // create new Nodes.
-	            Node node = new Node (rel.otherType, rs, safe);
+	            Node node = new Node (rel.otherType, rs, columns, safe);
 	            Key primKey = node.getKey ();
 	            retval.add (new NodeHandle (primKey));
 	            // do we need to synchronize on primKey here?
@@ -807,13 +808,14 @@ public final class NodeManager {
 	    if (missing > 0) {
 	        Connection con = dbm.getConnection ();
 	        Statement stmt = con.createStatement ();
+	        String[] columns = dbm.getColumns ();
 	        StringBuffer q = dbm.getSelect ();
 	        try {
 	            String idfield = rel.groupby != null ? rel.groupby : dbm.getIDField ();
 	            boolean needsQuotes = dbm.needsQuotes (idfield);
-	            q.append (" where ");
+	            q.append ("WHERE ");
 	            q.append (idfield);
-	            q.append (" in (");
+	            q.append (" IN (");
 	            boolean first = true;
 	            for (int i=0; i<keys.length; i++) {
 	                if (keys[i] != null) {
@@ -855,7 +857,7 @@ public final class NodeManager {
 
 	            while (rs.next ()) {
 	                // create new Nodes.
-	                Node node = new Node (dbm, rs, safe);
+	                Node node = new Node (dbm, rs, columns, safe);
 	                Key primKey = node.getKey ();
 
 	                // for grouped nodes, collect subnode lists for the intermediary
@@ -1035,8 +1037,9 @@ public final class NodeManager {
 	        Connection con = dbm.getConnection ();
 	        stmt = con.createStatement ();
 
+	        String[] columns = dbm.getColumns ();
 	        StringBuffer q = dbm.getSelect ();
-	        q.append (" where ");
+	        q.append ("WHERE ");
 	        q.append (idfield);
 	        q.append (" = ");
 	        q.append (kstr);
@@ -1048,7 +1051,7 @@ public final class NodeManager {
 
 	        if (!rs.next ())
 	            return null;
-	        node = new Node (dbm, rs, safe);
+	        node = new Node (dbm, rs, columns, safe);
 	        if (rs.next ())
 	            throw new RuntimeException ("More than one value returned by query.");
 
@@ -1093,12 +1096,13 @@ public final class NodeManager {
 	    Statement stmt = null;
 	    try {
 	        DbMapping dbm = rel.otherType;
-	
+
 	        Connection con = dbm.getConnection ();
+	        String[] columns = dbm.getColumns ();
 	        StringBuffer q = dbm.getSelect ();
 	        if (home.getSubnodeRelation () != null) {
 	            // combine our key with the constraints in the manually set subnode relation
-	            q.append (" WHERE ");
+	            q.append ("WHERE ");
 	            q.append (rel.accessor);
 	            q.append (" = '");
 	            q.append (escape(kstr));
@@ -1106,7 +1110,7 @@ public final class NodeManager {
 	            q.append (" AND ");
                     q.append (home.getSubnodeRelation().trim().substring(5));
 	        } else {
-	            q.append (rel.buildQuery (home, home.getNonVirtualParent (), kstr, " WHERE ", false));
+	            q.append (rel.buildQuery (home, home.getNonVirtualParent (), kstr, "WHERE ", false));
 	        }
 	        if (logSql)
 	            app.logEvent ("### getNodeByRelation: "+q.toString());
@@ -1116,7 +1120,7 @@ public final class NodeManager {
 
 	        if (!rs.next ())
 	            return null;
-	        node = new Node (rel.otherType, rs, safe);
+	        node = new Node (rel.otherType, rs, columns, safe);
 	        if (rs.next ())
 	            throw new RuntimeException ("More than one value returned by query.");