#108 Workaround for GROUP BY <integer> (#109)

Co-authored-by: Christoph Kuhnke <[email protected]>

.github/workflows/ci-build.yml

@@ -11,9 +11,9 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        docker_db_version: [ 7.1.17, 7.0.20 ]
+        docker_db_version: ["7.1.21"]
     env:
-      DEFAULT_DB_VERSION: "7.1.17"
+      DEFAULT_DB_VERSION: "7.1.21"
     runs-on: ubuntu-latest
     concurrency:
       group: ${{ github.workflow }}-${{ github.ref }}-${{ matrix.docker_db_version }}
@@ -25,9 +25,9 @@ jobs:
       - name: Set up JDK 11
         uses: actions/setup-java@v3
         with:
-          distribution: 'temurin'
+          distribution: "temurin"
           java-version: 11
-          cache: 'maven'
+          cache: "maven"
       - name: Cache SonarCloud packages
         uses: actions/cache@v3
         with:

.vscode/settings.json

@@ -1,17 +1,21 @@
 {
-    "editor.formatOnSave": true,
-    "editor.codeActionsOnSave": {
-        "source.organizeImports": true,
-        "source.generate.finalModifiers": true,
-        "source.fixAll": true
-    },
-    "java.codeGeneration.useBlocks": true,
-    "java.saveActions.organizeImports": true,
-    "java.sources.organizeImports.starThreshold": 3,
-    "java.sources.organizeImports.staticStarThreshold": 3,
-    "java.test.config": {
-        "vmArgs": [
-            "-Djava.util.logging.config.file=src/test/resources/logging.properties"
-        ]
-    },
+  "editor.formatOnSave": true,
+  "editor.codeActionsOnSave": {
+    "source.organizeImports": true,
+    "source.generate.finalModifiers": true,
+    "source.fixAll": true
+  },
+  "java.codeGeneration.useBlocks": true,
+  "java.saveActions.organizeImports": true,
+  "java.sources.organizeImports.starThreshold": 3,
+  "java.sources.organizeImports.staticStarThreshold": 3,
+  "java.test.config": {
+    "vmArgs": [
+      "-Djava.util.logging.config.file=src/test/resources/logging.properties"
+    ]
+  },
+  "sonarlint.connectedMode.project": {
+    "connectionId": "exasol",
+    "projectKey": "com.exasol:exasol-virtual-schema"
+  }
 }

README.md

@@ -45,6 +45,7 @@ Find all the documentation in the [Virtual Schemas project][vs-doc].
 ## Information for Developers
 
 * [Virtual Schema API Documentation][vs-api]
+* [Developer Guide](./doc/developer_guide.md)
 
 <!-- @formatter:off -->
 [virtual-schemas-user-guide]: https://docs.exasol.com/database_concepts/virtual_schemas.htm

doc/changes/changes_7.1.4.md

@@ -0,0 +1,34 @@
+# Exasol Virtual Schema 7.1.4, released 2023-07-12
+
+Code name: Fix Issue With Integer Constants in `GROUP BY`
+
+## Summary
+
+This release fixes an issue with queries using `DISTINCT` with integer constants. The Exasol SQL processor turns `DISTINCT <integer>` into `GROUP BY <integer>` before push-down as an optimization. The adapter must not feed this back as Exasol interprets integers in `GROUP BY` clauses as column numbers which could lead to invalid results or the following error:
+
+```
+42000:Wrong column number. Too small value 0 as select list column reference in GROUP BY (smallest possible value is 1)
+```
+
+To fix this, Exasol VS now replaces integer constants in `GROUP BY` clauses with a constant string.
+
+Please that you can still safely use `GROUP BY <column-number>` in your original query, since Exasol internally converts this to `GROUP BY "<column-name>"`, so that the virtual schema adapter can tell both situations apart.
+
+## Bugfixes
+
+* #108: Fixed issue with integer constants in `GROUP BY`
+
+## Dependency Updates
+
+### Compile Dependency Updates
+
+* Updated `com.exasol:virtual-schema-common-jdbc:11.0.0` to `11.0.1`
+
+### Test Dependency Updates
+
+* Updated `com.exasol:exasol-testcontainers:6.6.0` to `6.6.1`
+* Updated `com.exasol:virtual-schema-common-jdbc:11.0.0` to `11.0.1`
+
+### Plugin Dependency Updates
+
+* Updated `org.apache.maven.plugins:maven-assembly-plugin:3.3.0` to `3.6.0`

doc/developer_guide.md

@@ -0,0 +1,5 @@
+# Developer Guide
+
+## Enable Debug Output
+
+To enable debug output for the virtual schema adapter you can set [system properties defined by test-db-builder-java](https://github.com/exasol/test-db-builder-java/blob/main/doc/user_guide/user_guide.md#debug-output).

doc/dialects/exasol.md

@@ -17,7 +17,7 @@ The SQL statement below creates the adapter script, defines the Java class that
 ```sql
 CREATE JAVA ADAPTER SCRIPT SCHEMA_FOR_VS_SCRIPT.ADAPTER_SCRIPT_EXASOL AS
     %scriptclass com.exasol.adapter.RequestDispatcher;
-    %jar /buckets/<BFS service>/<bucket>/virtual-schema-dist-11.0.0-exasol-7.1.3.jar;
+    %jar /buckets/<BFS service>/<bucket>/virtual-schema-dist-11.0.1-exasol-7.1.4.jar;
 /
 ```
 

pom.xml

@@ -2,23 +2,13 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>exasol-virtual-schema</artifactId>
-    <version>7.1.3</version>
+    <version>7.1.4</version>
     <name>Exasol Virtual Schema</name>
     <description>This projects contains the Exasol dialect for Exasol's Virtual Schema</description>
     <url>https://github.com/exasol/exasol-virtual-schema/</url>
     <properties>
-        <vscjdbc.version>11.0.0</vscjdbc.version>
+        <vscjdbc.version>11.0.1</vscjdbc.version>
     </properties>
-    <distributionManagement>
-        <snapshotRepository>
-            <id>ossrh</id>
-            <url>https://oss.sonatype.org/content/repositories/snapshots</url>
-        </snapshotRepository>
-        <repository>
-            <id>ossrh</id>
-            <url>https://oss.sonatype.org/service/local/staging/deploy/maven2/</url>
-        </repository>
-    </distributionManagement>
     <dependencies>
         <dependency>
             <groupId>com.exasol</groupId>
@@ -66,7 +56,7 @@
         <dependency>
             <groupId>com.exasol</groupId>
             <artifactId>exasol-testcontainers</artifactId>
-            <version>6.6.0</version>
+            <version>6.6.1</version>
             <scope>test</scope>
         </dependency>
         <dependency>
@@ -116,13 +106,8 @@
             </plugin>
             <plugin>
                 <artifactId>maven-assembly-plugin</artifactId>
-                <version>3.3.0</version>
                 <configuration>
-                    <descriptors>
-                        <descriptor>src/assembly/all-dependencies.xml</descriptor>
-                    </descriptors>
                     <finalName>virtual-schema-dist-${vscjdbc.version}-exasol-${project.version}</finalName>
-                    <appendAssemblyId>false</appendAssemblyId>
                 </configuration>
                 <executions>
                     <execution>
@@ -159,19 +144,6 @@
                     <useModulePath>false</useModulePath>
                 </configuration>
             </plugin>
-            <plugin>
-                <groupId>org.sonatype.ossindex.maven</groupId>
-                <artifactId>ossindex-maven-plugin</artifactId>
-                <configuration>
-                    <excludeVulnerabilityIds>
-                        <!-- This is a vulnerability in the transitive netty test dependency introduced by the
-                        AWS SDK and in turn by exasol-test-setup-abstraction-java. AWS notes that they handle
-                        netty in a way where this cannot be exploited.
-                        See https://github.com/aws/aws-sdk-java-v2/issues/3263#issuecomment-1163600532 -->
-                        <exclude>sonatype-2020-0026</exclude>
-                    </excludeVulnerabilityIds>
-                </configuration>
-            </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
@@ -190,7 +162,7 @@
     <parent>
         <artifactId>exasol-virtual-schema-generated-parent</artifactId>
         <groupId>com.exasol</groupId>
-        <version>7.1.3</version>
+        <version>7.1.4</version>
         <relativePath>pk_generated_parent.pom</relativePath>
     </parent>
 </project>

src/test/java/com/exasol/adapter/dialects/exasol/AbstractExasolSqlDialectIT.java

@@ -77,14 +77,6 @@ private static AdapterScript installVirtualSchemaAdapter(final ExasolSchema adap
                 .build();
     }
 
-    protected static boolean exasolVersionSupportsFingerprintInAddress() {
-        final ExasolDockerImageReference imageReference = EXASOL.getDockerImageReference();
-        if (imageReference.getMajor() >= 8) {
-            return true;
-        }
-        return (imageReference.getMajor() >= 7) && (imageReference.getMinor() >= 1);
-    }
-
     @AfterAll
     static void afterAll() throws SQLException {
         dropAll(adapterScript, adapterSchema);
@@ -108,11 +100,8 @@ private ConnectionDefinition createAdapterConnectionDefinition(final User user)
 
     private String getJdbcUrl() {
         final int port = EXASOL.getDefaultInternalDatabasePort();
-        if (exasolVersionSupportsFingerprintInAddress()) {
-            final String fingerprint = EXASOL.getTlsCertificateFingerprint().orElseThrow();
-            return "jdbc:exa:localhost/" + fingerprint + ":" + port;
-        }
-        return "jdbc:exa:localhost:" + port + ";validateservercertificate=0";
+        final String fingerprint = EXASOL.getTlsCertificateFingerprint().orElseThrow();
+        return "jdbc:exa:localhost/" + fingerprint + ":" + port;
     }
 
     @AfterEach
@@ -171,6 +160,13 @@ protected VirtualSchema createVirtualSchema(final Schema sourceSchema) {
                 .build();
     }
 
+    /**
+     * Get properties for the virtual schema. Note: if you want to enable debug output, you can set <a href=
+     * "https://github.com/exasol/test-db-builder-java/blob/main/doc/user_guide/user_guide.md#debug-output">system
+     * properties defined by test-db-builder-java</a>.
+     * 
+     * @return properties for the virtual schema
+     */
     private Map<String, String> getVirtualSchemaProperties() {
         return getConnectionSpecificVirtualSchemaProperties();
     }
@@ -855,6 +851,42 @@ void testWildcards() throws SQLException {
                 table().row("A", "VARCHAR(20) UTF8", null, null, null).matches());
     }
 
+    @Test
+    @DisplayName("Verify DISTINCT with integer literal")
+    void testDistinctWithIntegerLiteral() throws SQLException {
+        final Table table = createSingleColumnTable("INT") //
+                .insert(1).insert(1).insert(2).insert(3);
+        final VirtualSchema virtualSchema = createVirtualSchema(this.sourceSchema);
+        try {
+            assertThat(
+                    query("SELECT DISTINCT c1, 0 AS attr from "
+                            + virtualSchema.getFullyQualifiedName() + "." + table.getName()),
+                    table("BIGINT", "SMALLINT") //
+                            .row(1L, (short) 0).row(2L, (short) 0).row(3L, (short) 0) //
+                            .matchesInAnyOrder());
+        } finally {
+            virtualSchema.drop();
+        }
+    }
+
+    @Test
+    @DisplayName("Verify GROUP BY with column number reference")
+    void testGroupByWithColumnNumber() throws SQLException {
+        final Table table = createSingleColumnTable("INT") //
+                .insert(1).insert(1).insert(2).insert(3);
+        final VirtualSchema virtualSchema = createVirtualSchema(this.sourceSchema);
+        try {
+            assertThat(
+                    query("SELECT c1, count(c1) as count from "
+                            + virtualSchema.getFullyQualifiedName() + "." + table.getName() + " group by 1"),
+                    table("BIGINT", "BIGINT") //
+                            .row(1L, 2L).row(2L, 1L).row(3L, 1L) //
+                            .matchesInAnyOrder());
+        } finally {
+            virtualSchema.drop();
+        }
+    }
+
     boolean isVersionOrHigher(final int majorVersion, final int minorVersion, final int fixVersion) {
         final ExasolDockerImageReference version = EXASOL.getDockerImageReference();
         final long comparableImageVersion = calculatedComparableVersion((version.hasMajor() ? version.getMajor() : 0),

src/test/java/com/exasol/adapter/dialects/exasol/ExasolSqlDialectExaConnectionIT.java

@@ -47,10 +47,8 @@ void beforeEach() {
     }
 
     private String getTargetAddress() {
-        final String fingerprint = exasolVersionSupportsFingerprintInAddress()
-                ? "/" + EXASOL.getTlsCertificateFingerprint().orElseThrow()
-                : "";
-        return "127.0.0.1" + fingerprint + ":" + EXASOL.getDefaultInternalDatabasePort();
+        return "127.0.0.1" + "/" + EXASOL.getTlsCertificateFingerprint().orElseThrow() + ":"
+                + EXASOL.getDefaultInternalDatabasePort();
     }
 
     @Override

src/test/java/com/exasol/adapter/dialects/exasol/IntegrationTestConfiguration.java

@@ -3,12 +3,12 @@
 import java.nio.file.Path;
 
 public final class IntegrationTestConfiguration {
-    private static final String DEFAULT_DOCKER_DB_REFERENCE = "7.1.17";
+    private static final String DEFAULT_DOCKER_DB_REFERENCE = "7.1.21";
     /**
      * Do not use MavenProjectVersionGetter here to enable reference checker to check if reference points to the latest
      * version.
      */
-    public static final String VIRTUAL_SCHEMAS_JAR_NAME_AND_VERSION = "virtual-schema-dist-11.0.0-exasol-7.1.3.jar";
+    public static final String VIRTUAL_SCHEMAS_JAR_NAME_AND_VERSION = "virtual-schema-dist-11.0.1-exasol-7.1.4.jar";
     public static final Path PATH_TO_VIRTUAL_SCHEMAS_JAR = Path.of("target", VIRTUAL_SCHEMAS_JAR_NAME_AND_VERSION);
 
     private IntegrationTestConfiguration() {