Linked tables now support default values.

h2/src/main/org/h2/command/dml/Update.java

@@ -96,15 +96,7 @@ public class Update extends Prepared {
                             newValue = oldRow.getValue(i);
                         } else if (newExpr == ValueExpression.getDefault()) {
                             Column column = table.getColumn(i);
-                            Expression defaultExpr = column.getDefaultExpression();
-                            Value v;
-                            if (defaultExpr == null) {
-                                v = column.validateConvertUpdateSequence(session, null);
-                            } else {
-                                v = defaultExpr.getValue(session);
-                            }
-                            int type = column.getType();
-                            newValue = v.convertTo(type);
+                            newValue = table.getDefaultValue(session, column);
                         } else {
                             Column column = table.getColumn(i);
                             newValue = newExpr.getValue(session).convertTo(column.getType());

h2/src/main/org/h2/index/LinkedIndex.java

@@ -55,8 +55,10 @@ public class LinkedIndex extends BaseIndex {
         buff.append(targetTableName).append(" VALUES(");
         for (int i = 0; i < row.getColumnCount(); i++) {
             Value v = row.getValue(i);
-            buff.appendExceptFirst(",");
-            if (isNull(v)) {
+            buff.appendExceptFirst(", ");
+            if (v == null) {
+                buff.append("DEFAULT");
+            } else if (isNull(v)) {
                 buff.append("NULL");
             } else {
                 buff.append('?');
@@ -221,7 +223,13 @@ public class LinkedIndex extends BaseIndex {
         buff.append(targetTableName).append(" SET ");
         for (int i = 0; i < newRow.getColumnCount(); i++) {
             buff.appendExceptFirst(", ");
-            buff.append(table.getColumn(i).getSQL()).append("=?");
+            buff.append(table.getColumn(i).getSQL()).append('=');
+            Value v = newRow.getValue(i);
+            if (v == null) {
+                buff.append("DEFAULT");
+            } else {
+                buff.append('?');
+            }
         }
         buff.append(" WHERE ");
         buff.resetCount();
@@ -243,8 +251,11 @@ public class LinkedIndex extends BaseIndex {
                 int j = 1;
                 PreparedStatement prep = link.getPreparedStatement(sql, false);
                 for (int i = 0; i < newRow.getColumnCount(); i++) {
-                    newRow.getValue(i).set(prep, j);
-                    j++;
+                    Value v = newRow.getValue(i);
+                    if (v != null) {
+                        v.set(prep, j);
+                        j++;
+                    }
                 }
                 for (int i = 0; i < oldRow.getColumnCount(); i++) {
                     Value v = oldRow.getValue(i);

h2/src/main/org/h2/result/RowList.java

@@ -62,24 +62,29 @@ public class RowList {
         buff.writeInt(r.getStorageId());
         for (int i = 0; i < r.getColumnCount(); i++) {
             Value v = r.getValue(i);
-            if (v.getType() == Value.CLOB || v.getType() == Value.BLOB) {
-                // need to keep a reference to temporary lobs,
-                // otherwise the temp file is deleted
-                ValueLob lob = (ValueLob) v;
-                if (lob.getSmall() == null && lob.getTableId() == 0) {
-                    if (lobs == null) {
-                        lobs = ObjectArray.newInstance();
+            if (v == null) {
+                buff.writeByte((byte) 0);
+            } else {
+                buff.writeByte((byte) 1);
+                if (v.getType() == Value.CLOB || v.getType() == Value.BLOB) {
+                    // need to keep a reference to temporary lobs,
+                    // otherwise the temp file is deleted
+                    ValueLob lob = (ValueLob) v;
+                    if (lob.getSmall() == null && lob.getTableId() == 0) {
+                        if (lobs == null) {
+                            lobs = ObjectArray.newInstance();
+                        }
+                        // need to create a copy, otherwise,
+                        // if stored multiple times, it may be renamed
+                        // and then not found
+                        lob = lob.copyToTemp();
+                        lobs.add(lob);
+                        v = lob;
                     }
-                    // need to create a copy, otherwise,
-                    // if stored multiple times, it may be renamed
-                    // and then not found
-                    lob = lob.copyToTemp();
-                    lobs.add(lob);
-                    v = lob;
                 }
+                buff.checkCapacity(buff.getValueLen(v));
+                buff.writeValue(v);
             }
-            buff.checkCapacity(buff.getValueLen(v));
-            buff.writeValue(v);
         }
     }
 
@@ -180,13 +185,18 @@ public class RowList {
         int storageId = buff.readInt();
         Value[] values = new Value[columnCount];
         for (int i = 0; i < columnCount; i++) {
-            Value v = buff.readValue();
-            if (v.isLinked()) {
-                ValueLob lob = (ValueLob) v;
-                // the table id is 0 if it was linked when writing
-                // a temporary entry
-                if (lob.getTableId() == 0) {
-                    session.unlinkAtCommit(lob);
+            Value v;
+            if (buff.readByte() == 0) {
+                v = null;
+            } else {
+                v = buff.readValue();
+                if (v.isLinked()) {
+                    ValueLob lob = (ValueLob) v;
+                    // the table id is 0 if it was linked when writing
+                    // a temporary entry
+                    if (lob.getTableId() == 0) {
+                        session.unlinkAtCommit(lob);
+                    }
                 }
             }
             values[i] = v;

h2/src/main/org/h2/table/Table.java

@@ -18,6 +18,7 @@ import org.h2.engine.Constants;
 import org.h2.engine.DbObject;
 import org.h2.engine.Right;
 import org.h2.engine.Session;
+import org.h2.expression.Expression;
 import org.h2.expression.ExpressionVisitor;
 import org.h2.index.Index;
 import org.h2.index.IndexType;
@@ -936,4 +937,23 @@ public abstract class Table extends SchemaObjectBase {
         return compareMode;
     }
 
+    /**
+     * Get or generate a default value for the given column.
+     *
+     * @param session the session
+     * @param column the column
+     * @return the value
+     */
+    public Value getDefaultValue(Session session, Column column) throws SQLException {
+        Expression defaultExpr = column.getDefaultExpression();
+        Value v;
+        if (defaultExpr == null) {
+            v = column.validateConvertUpdateSequence(session, null);
+        } else {
+            v = defaultExpr.getValue(session);
+        }
+        int type = column.getType();
+        return  v.convertTo(type);
+    }
+
 }

h2/src/main/org/h2/table/TableLink.java

@@ -33,6 +33,7 @@ import org.h2.util.New;
 import org.h2.util.ObjectArray;
 import org.h2.util.StringUtils;
 import org.h2.value.DataType;
+import org.h2.value.Value;
 import org.h2.value.ValueDate;
 import org.h2.value.ValueTime;
 import org.h2.value.ValueTimestamp;
@@ -542,4 +543,37 @@ public class TableLink extends Table {
         return false;
     }
 
+    /**
+     * Convert the values if required. Default values are not set (kept as
+     * null).
+     *
+     * @param session the session
+     * @param row the row
+     */
+    public void validateConvertUpdateSequence(Session session, Row row) throws SQLException {
+        for (int i = 0; i < columns.length; i++) {
+            Value value = row.getValue(i);
+            if (value != null) {
+                // null means use the default value
+                Column column = columns[i];
+                Value v2 = column.validateConvertUpdateSequence(session, value);
+                if (v2 != value) {
+                    row.setValue(i, v2);
+                }
+            }
+        }
+    }
+
+    /**
+     * Get or generate a default value for the given column. Default values are
+     * not set (kept as null).
+     *
+     * @param session the session
+     * @param column the column
+     * @return the value
+     */
+    public Value getDefaultValue(Session session, Column column) {
+        return null;
+    }
+
 }

h2/src/test/org/h2/test/db/TestLinkedTable.java

@@ -33,6 +33,7 @@ public class TestLinkedTable extends TestBase {
     }
 
     public void test() throws SQLException {
+        testDefaultValues();
         testHiddenSQL();
         // testLinkAutoAdd();
         testNestedQueriesToSameTable();
@@ -50,6 +51,47 @@ public class TestLinkedTable extends TestBase {
         deleteDb("linkedTable");
     }
 
+    private void testDefaultValues() throws SQLException {
+        if (config.memory) {
+            return;
+        }
+        deleteDb("linkedTable");
+        Connection connMain = DriverManager.getConnection("jdbc:h2:mem:linkedTable");
+        Statement statMain = connMain.createStatement();
+        statMain.execute("create table test(id identity, name varchar default 'test')");
+
+        Connection conn = getConnection("linkedTable");
+        Statement stat = conn.createStatement();
+        stat.execute("create linked table test1('', 'jdbc:h2:mem:linkedTable', '', '', 'TEST') emit updates");
+        stat.execute("create linked table test2('', 'jdbc:h2:mem:linkedTable', '', '', 'TEST')");
+        stat.execute("insert into test1 values(default, default)");
+        stat.execute("insert into test2 values(default, default)");
+        stat.execute("merge into test2 values(3, default)");
+        stat.execute("update test1 set name=default where id=1");
+        stat.execute("update test2 set name=default where id=2");
+
+        ResultSet rs = statMain.executeQuery("select * from test order by id");
+        rs.next();
+        assertEquals(1, rs.getInt(1));
+        assertEquals("test", rs.getString(2));
+        rs.next();
+        assertEquals(2, rs.getInt(1));
+        assertEquals("test", rs.getString(2));
+        rs.next();
+        assertEquals(3, rs.getInt(1));
+        assertEquals("test", rs.getString(2));
+        assertFalse(rs.next());
+
+        stat.execute("delete from test1 where id=1");
+        stat.execute("delete from test2 where id=2");
+        stat.execute("delete from test2 where id=3");
+        conn.close();
+        rs = statMain.executeQuery("select * from test order by id");
+        assertFalse(rs.next());
+
+        connMain.close();
+    }
+
     private void testHiddenSQL() throws SQLException {
         if (config.memory || !SysProperties.SHARE_LINKED_CONNECTIONS) {
             return;