Issue #694: Support for Oracle style parenthesised column modification:

ALTER TABLE foo MODIFY (bar VARCHAR2(255) NOT NULL)

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

@@ -6143,6 +6143,7 @@ public class Parser {
         } else if (readIf("MODIFY")) {
             // MySQL compatibility
             readIf("COLUMN"); // optional
+            boolean hasOpeningBracket = readIf("("); // Oracle specifies (but will not require) an opening parenthesis
             String columnName = readColumnIdentifier();
             AlterTableAlterColumn command = null;
             NullConstraintType nullConstraint = parseNotNullConstraint();
@@ -6167,6 +6168,9 @@ public class Parser {
                 throw DbException.get(ErrorCode.UNKNOWN_MODE_1,
                         "Internal Error - unhandled case: " + nullConstraint.name());
             }
+            if(hasOpeningBracket) {
+                read(")");
+            }
             return command;
         } else if (readIf("ALTER")) {
             readIf("COLUMN");

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

@@ -52,6 +52,7 @@ public class TestAlter extends TestBase {
         testAlterTableAddMultipleColumnsAfter();
         testAlterTableModifyColumn();
         testAlterTableModifyColumnSetNull();
+        testAlterTableModifyColumnNotNullOracle();
         conn.close();
         deleteDb(getTestName());
     }
@@ -317,4 +318,16 @@ public class TestAlter extends TestBase {
         stat.execute("insert into T values(null)"); // <- Fixed in v1.4.196 - NULL is allowed
         stat.execute("drop table T");
     }
+
+    private void testAlterTableModifyColumnNotNullOracle() throws SQLException {
+        stat.execute("create table foo (bar varchar(255))");
+        stat.execute("alter table foo modify (bar varchar(255) not null)");
+        try {
+            stat.execute("insert into foo values(null)");
+            fail("Null should not be allowed after modification.");
+        }
+        catch(SQLException e) {
+            // This is what we expect, fails to insert null.
+        }
+    }
 }