Add support for ALTER TABLE ... RENAME CONSTRAINT .. TO ...

h2/src/docsrc/help/help.csv

@@ -246,6 +246,15 @@ This command commits an open transaction in this connection.
 ALTER TABLE TEST ADD CONSTRAINT NAME_UNIQUE UNIQUE(NAME)
 "
 
+"Commands (DDL)","ALTER TABLE RENAME CONSTRAINT","
+ALTER TABLE tableName RENAME oldConstraintName TO newConstraintName
+","
+Renames a constraint.
+This command commits an open transaction in this connection.
+","
+ALTER TABLE TEST RENAME CONSTRAINT FOO TO BAR
+"
+
 "Commands (DDL)","ALTER TABLE ALTER COLUMN","
 ALTER TABLE tableName ALTER COLUMN columnName
 { { dataType [ DEFAULT expression ] [ [ NOT ] NULL ] [ AUTO_INCREMENT | IDENTITY ] }

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Add support for ALTER TABLE ... RENAME CONSTRAINT .. TO ...
+</li>
 <li>Add support for PostgreSQL ALTER TABLE ... RENAME COLUMN .. TO ...
 </li>
 <li>Improve performance of cleaning up temp tables - patch from Eric Faulhaber.

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

@@ -451,6 +451,11 @@ public interface CommandInterface {
      */
     int SHUTDOWN_DEFRAG = 84;
 
+    /**
+     * The type of a ALTER TABLE RENAME CONSTRAINT statement.
+     */
+    int ALTER_TABLE_RENAME_CONSTRAINT = 85;
+
     /**
      * Get command type.
      *

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

@@ -25,6 +25,7 @@ import org.h2.command.ddl.AlterTableAlterColumn;
 import org.h2.command.ddl.AlterTableDropConstraint;
 import org.h2.command.ddl.AlterTableRename;
 import org.h2.command.ddl.AlterTableRenameColumn;
+import org.h2.command.ddl.AlterTableRenameConstraint;
 import org.h2.command.ddl.AlterUser;
 import org.h2.command.ddl.AlterView;
 import org.h2.command.ddl.Analyze;
@@ -5434,6 +5435,17 @@ public class Parser {
                 String newName = readColumnIdentifier();
                 command.setNewColumnName(newName);
                 return command;
+            } else if (readIf("CONSTRAINT")) {
+                String constraintName = readIdentifierWithSchema(table
+                        .getSchema().getName());
+                checkSchema(table.getSchema());
+                read("TO");
+                AlterTableRenameConstraint command = new AlterTableRenameConstraint(
+                        session, table.getSchema());
+                command.setConstraintName(constraintName);
+                String newName = readColumnIdentifier();
+                command.setNewConstraintName(newName);
+                return command;
             } else {
                 read("TO");
                 String newName = readIdentifierWithSchema(table.getSchema()

h2/src/main/org/h2/command/ddl/AlterTableRenameConstraint.java

+/*
+ * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
+ * and the EPL 1.0 (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.command.ddl;
+
+import org.h2.api.ErrorCode;
+import org.h2.command.CommandInterface;
+import org.h2.constraint.Constraint;
+import org.h2.engine.Right;
+import org.h2.engine.Session;
+import org.h2.message.DbException;
+import org.h2.schema.Schema;
+
+/**
+ * This class represents the statement
+ * ALTER TABLE RENAME CONSTRAINT
+ */
+public class AlterTableRenameConstraint extends SchemaCommand {
+
+    private String constraintName;
+    private String newConstraintName;
+
+    public AlterTableRenameConstraint(Session session, Schema schema) {
+        super(session, schema);
+    }
+
+    public void setConstraintName(String string) {
+        constraintName = string;
+    }
+    public void setNewConstraintName(String newName) {
+        this.newConstraintName = newName;
+    }
+
+    @Override
+    public int update() {
+        session.commit(true);
+        Constraint constraint = getSchema().findConstraint(session, constraintName);
+        if (constraint == null) {
+            throw DbException.get(ErrorCode.CONSTRAINT_NOT_FOUND_1, constraintName);
+        }
+        if (getSchema().findConstraint(session, newConstraintName) != null ||
+                newConstraintName.equals(constraintName)) {
+            throw DbException.get(ErrorCode.CONSTRAINT_ALREADY_EXISTS_1,
+                    newConstraintName);
+        }
+        session.getUser().checkRight(constraint.getTable(), Right.ALL);
+        session.getUser().checkRight(constraint.getRefTable(), Right.ALL);
+        session.getDatabase().renameSchemaObject(session, constraint, newConstraintName);
+        return 0;
+    }
+
+    @Override
+    public int getType() {
+        return CommandInterface.ALTER_TABLE_RENAME_CONSTRAINT;
+    }
+
+}

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

@@ -35,6 +35,7 @@ public class TestAlter extends TestBase {
         deleteDb(getTestName());
         conn = getConnection(getTestName());
         stat = conn.createStatement();
+        testAlterTableRenameConstraint();
         testAlterTableAlterColumnAsSelfColumn();
         testAlterTableDropColumnWithReferences();
         testAlterTableDropMultipleColumns();
@@ -140,6 +141,13 @@ public class TestAlter extends TestBase {
         stat.execute("drop table test");
     }
 
+    private void testAlterTableRenameConstraint() throws SQLException {
+        stat.execute("create table test(id int, name varchar(255))");
+        stat.execute("alter table test add constraint x check (id > name)");
+        stat.execute("alter table test rename constraint x to x2");
+        stat.execute("drop table test");
+    }
+
     private void testAlterTableDropIdentityColumn() throws SQLException {
         stat.execute("create table test(id int auto_increment, name varchar)");
         stat.execute("alter table test drop column id");