Issue 478: Support for "SHOW TRANSACTION ISOLATION LEVEL", patch from Andrew Franklin

h2/src/docsrc/html/changelog.html

@@ -34,6 +34,7 @@ Change Log
 </li><li>Fix potential UTF8 encoding issue in org.h2.store.FileStore, reported by Juerg Spiess
 </li><li>Improve error message when check constraint is broken, test case from Gili (cowwoc)
 </li><li>Improve error message when we have a unique constraint violation, displays the offending key in the error message
+</li><li>Issue 478: Support for "SHOW TRANSACTION ISOLATION LEVEL", patch from Andrew Franklin 
 </li></ul>
 
 <h2>Version 1.3.172 (2013-05-25)</h2>

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

@@ -838,6 +838,11 @@ public class Parser {
         } else if (readIf("DEFAULT_TRANSACTION_ISOLATION")) {
             // for PostgreSQL compatibility
             buff.append("'read committed' AS DEFAULT_TRANSACTION_ISOLATION FROM DUAL");
+        } else if (readIf("TRANSACTION")) {
+            // for PostgreSQL compatibility
+            read("ISOLATION");
+            read("LEVEL");
+            buff.append("'read committed' AS TRANSACTION_ISOLATION FROM DUAL");
         } else if (readIf("DATESTYLE")) {
             // for PostgreSQL compatibility
             buff.append("'ISO' AS DATESTYLE FROM DUAL");

h2/src/test/org/h2/test/TestAll.java

@@ -61,6 +61,7 @@ import org.h2.test.db.TestScriptSimple;
 import org.h2.test.db.TestSelectCountNonNullColumn;
 import org.h2.test.db.TestSequence;
 import org.h2.test.db.TestSessionsLocks;
+import org.h2.test.db.TestShow;
 import org.h2.test.db.TestSpaceReuse;
 import org.h2.test.db.TestSpeed;
 import org.h2.test.db.TestTableEngines;
@@ -621,6 +622,7 @@ kill -9 `jps -l | grep "org.h2.test." | cut -d " " -f 1`
         new TestSessionsLocks().runTest(this);
         new TestSelectCountNonNullColumn().runTest(this);
         new TestSequence().runTest(this);
+        new TestShow().runTest(this);
         new TestSpaceReuse().runTest(this);
         new TestSpeed().runTest(this);
         new TestTableEngines().runTest(this);

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

+/*
+ * Copyright 2004-2013 H2 Group. Multiple-Licensed under the H2 License,
+ * Version 1.0, and under the Eclipse Public License, Version 1.0
+ * (http://h2database.com/html/license.html).
+ * Initial Developer: H2 Group
+ */
+package org.h2.test.db;
+
+import org.h2.test.TestBase;
+
+import java.sql.Connection;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+/** Test of compatability for the SHOW statement */
+public class TestShow extends TestBase {
+    /**
+     * Run just this test.
+     *
+     * @param a ignored
+     */
+    public static void main(String... a) throws Exception {
+        TestBase.createCaller().init().test();
+    }
+
+    @Override
+    public void test() throws SQLException {
+        testPgCompat();
+        testMysqlCompat();
+    }
+
+    private void testPgCompat() throws SQLException {
+        Connection conn = getConnection("mem:showtest");
+        Statement stat = conn.createStatement();
+
+        assertResult("UNICODE", stat, "SHOW CLIENT_ENCODING");
+        assertResult("read committed", stat, "SHOW DEFAULT_TRANSACTION_ISOLATION");
+        assertResult("read committed", stat, "SHOW TRANSACTION ISOLATION LEVEL");
+        assertResult("ISO", stat, "SHOW DATESTYLE");
+        assertResult("8.1.4", stat, "SHOW SERVER_VERSION");
+        assertResult("UTF8", stat, "SHOW SERVER_ENCODING");
+    }
+
+    private void testMysqlCompat() throws SQLException {
+        Connection conn = getConnection("mem:showtest");
+        Statement stat = conn.createStatement();
+        ResultSet rs;
+
+        // show tables without a schema
+        stat.execute("create table person(id int, name varchar)");
+        rs = stat.executeQuery("SHOW TABLES");
+        assertTrue(rs.next());
+        assertEquals("PERSON", rs.getString(1));
+        assertEquals("PUBLIC", rs.getString(2));
+        assertFalse(rs.next());
+
+        // show tables with a schema
+        assertResultRowCount(1, stat.executeQuery("SHOW TABLES FROM PUBLIC"));
+
+        // columns
+        assertResultRowCount(2, stat.executeQuery("SHOW COLUMNS FROM person"));
+    }
+}