--no commit message

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h2/src/docsrc/html/changelog.html

@@ -15,7 +15,7 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
-<li>-
+<li>UPDATE SET column=DEFAULT is now supported.
 </li></ul>
 
 <h2>Version 1.0.67 (2008-02-22)</h2>

h2/src/main/org/h2/command/Parser.java

@@ -635,7 +635,12 @@ public class Parser {
             do {
                 Column column = readTableColumn(filter);
                 read("=");
-                Expression expression = readExpression();
+                Expression expression;
+                if (readIf("DEFAULT")) {
+                    expression = ValueExpression.DEFAULT;
+                } else {
+                    expression = readExpression();
+                }
                 command.setAssignment(column, expression);
             } while (readIf(","));
         }

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

@@ -11,6 +11,7 @@ import org.h2.constant.ErrorCode;
 import org.h2.engine.Right;
 import org.h2.engine.Session;
 import org.h2.expression.Expression;
+import org.h2.expression.ValueExpression;
 import org.h2.message.Message;
 import org.h2.result.LocalResult;
 import org.h2.result.Row;
@@ -80,6 +81,9 @@ public class Update extends Prepared {
                         Value newValue;
                         if (newExpr == null) {
                             newValue = oldRow.getValue(i);
+                        } else if (newExpr == ValueExpression.DEFAULT) {
+                            Column column = table.getColumn(i);
+                            newValue = column.getDefaultExpression().getValue(session).convertTo(column.getType());
                         } else {
                             Column column = table.getColumn(i);
                             newValue = newExpr.getValue(session).convertTo(column.getType());

h2/src/main/org/h2/expression/ValueExpression.java

@@ -22,6 +22,7 @@ public class ValueExpression extends Expression {
     private Value value;
 
     public static final ValueExpression NULL = new ValueExpression(ValueNull.INSTANCE);
+    public static final ValueExpression DEFAULT = new ValueExpression(ValueNull.INSTANCE);
 
     public static ValueExpression get(Value v) {
         if (v == ValueNull.INSTANCE) {
@@ -86,8 +87,12 @@ public class ValueExpression extends Expression {
     }
 
     public String getSQL() {
+        if (this == DEFAULT) {
+            return "DEFAULT";
+        } else {
             return value.getSQL();
         }
+    }
 
     public void updateAggregate(Session session) throws SQLException {
     }

h2/src/main/org/h2/res/help.csv

@@ -29,7 +29,7 @@ INSERT INTO TEST VALUES(1, 'Hello')
 
 "Commands (DML)","UPDATE","
 UPDATE tableName
-SET {columnName=expression} [,...]
+SET {columnName= {DEFAULT | expression} } [,...]
 [WHERE expression]
 ","
 Updates data in a table.

h2/src/test/org/h2/test/test.in.txt

 --- special grammar and test cases ---------------------------------------------------------------------------------------------
+create table test(a int, b int default 1);
+> ok
+
+insert into test values(1, default), (2, 2), (3, null);
+> update count: 3
+
+select * from test;
+> A B
+> - ----
+> 1 1
+> 2 2
+> 3 null
+> rows: 3
+
+update test set b = default where a = 2;
+> update count: 1
+
+explain update test set b = default where a = 2;
+> PLAN
+> ---------------------------------------------------------------------------
+> UPDATE PUBLIC.TEST /* PUBLIC.TEST_TABLE_SCAN */ SET B = DEFAULT WHERE A = 2
+> rows: 1
+
+select * from test;
+> A B
+> - ----
+> 1 1
+> 2 1
+> 3 null
+> rows: 3
+
+drop table test;
+> ok
+
 CREATE ROLE X;
 > ok