fix(server): ensure graph clear API does not clear meta table

Author: LYD031106

hugegraph-server/hugegraph-mysql/src/main/java/org/apache/hugegraph/backend/store/mysql/MysqlStore.java

@@ -222,7 +222,6 @@ public void truncate() {
         this.checkOpened();
 
         this.truncateTables();
-        this.init();
         LOG.debug("Store truncated: {}", this.store);
     }
 
@@ -337,9 +336,6 @@ protected void clearTables() {
     protected void truncateTables() {
         Session session = this.sessions.session();
         for (MysqlTable table : this.tables()) {
-            if (table instanceof MysqlTables.Meta || table instanceof MysqlTables.Counters){
-                continue;
-            }
             table.truncate(session);
         }
     }
@@ -509,7 +505,6 @@ public String storedVersion() {
         @Override
         protected Collection<MysqlTable> tables() {
             List<MysqlTable> tables = new ArrayList<>(super.tables());
-            tables.add(this.meta);
             return tables;
         }
     }

hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/unit/mysql/BaseMysqlUnitTest.java

@@ -20,11 +20,11 @@
 package org.apache.hugegraph.unit.mysql;
 
 import org.apache.commons.configuration2.Configuration;
+import org.apache.hugegraph.backend.store.mysql.MysqlSessions;
 import org.apache.hugegraph.backend.store.mysql.MysqlStoreProvider;
 import org.apache.hugegraph.config.HugeConfig;
 import org.apache.hugegraph.testutil.Utils;
 import org.apache.hugegraph.unit.BaseUnitTest;
-import org.apache.hugegraph.unit.FakeObjects;
 import org.junit.After;
 
 public class BaseMysqlUnitTest extends BaseUnitTest {
@@ -33,20 +33,19 @@ public class BaseMysqlUnitTest extends BaseUnitTest {
 
     protected HugeConfig config;
     protected MysqlStoreProvider provider;
+    protected MysqlSessions sessions;
 
-    public void setup() {
-        try {
-            Configuration conf = Utils.getConf();
-            this.config = new HugeConfig(conf);
-        } catch (Exception e) {
-            this.config = FakeObjects.newConfig();
-        }
+    public void setup() throws Exception {
+        Configuration conf = Utils.getConf();
+        this.config = new HugeConfig(conf);
         this.provider = new MysqlStoreProvider();
         this.provider.open(GRAPH_NAME);
         this.provider.loadSystemStore(config).open(config);
         this.provider.loadGraphStore(config).open(config);
         this.provider.loadSchemaStore(config).open(config);
         this.provider.init();
+        this.sessions = new MysqlSessions(config, GRAPH_NAME, this.provider.loadGraphStore(config).store());
+        this.sessions.open();
     }
 
     @After
@@ -55,7 +54,7 @@ public void down(){
             try {
                 this.provider.close();
             } catch (Exception e) {
-                // pass
+                LOG.warn("Mysql provider close failed",e);
             }
         }
     }

hugegraph-server/hugegraph-test/src/main/java/org/apache/hugegraph/unit/mysql/MysqlTest.java

@@ -20,24 +20,91 @@
 package org.apache.hugegraph.unit.mysql;
 
 import org.apache.hugegraph.backend.store.BackendStore;
+import org.apache.hugegraph.backend.store.mysql.MysqlSessions;
+import org.apache.hugegraph.backend.store.mysql.ResultSetWrapper;
 import org.apache.hugegraph.testutil.Assert;
 import org.junit.Before;
 import org.junit.Test;
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
 
 public class MysqlTest extends BaseMysqlUnitTest{
     @Before
-    public void setUp(){
+    public void setUp() throws Exception {
         super.setup();
     }
 
     @Test
-    public void testMysqlMetaVersion(){
+    public void testMysqlMetaVersion() throws SQLException {
         BackendStore systemStore = this.provider.loadSystemStore(config);
+
+        // Record system version before truncation
         String beforeVersion = systemStore.storedVersion();
+
+        // Get sessions for direct table operations
+        MysqlSessions.Session session = this.sessions.session();
+        session.open();
+        
+        // Get the actual table names from the store
+        String vertexTable = "g_v";
+        String edgeOutTable = "g_oe";
+        String edgeInTable = "g_ie";
+        
+        // Insert test vertex data directly using simple SQL
+        String insertVertex = String.format(
+            "INSERT INTO %s (ID, LABEL, PROPERTIES, EXPIRED_TIME) VALUES ('test_vertex', 1, '{\"name\":\"test_vertex\"}', 0)",
+            vertexTable
+        );
+        session.execute(insertVertex);
+        
+        // Insert test edge data directly using simple SQL
+        String insertEdgeOut = String.format(
+            "INSERT INTO %s (OWNER_VERTEX, DIRECTION, LABEL, SUB_LABEL, SORT_VALUES, OTHER_VERTEX, PROPERTIES, EXPIRED_TIME) VALUES ('test_vertex', 0, 1, 0, '', 'target_vertex', '{\"weight\":1.0}', 0)",
+            edgeOutTable
+        );
+        session.execute(insertEdgeOut);
+        
+        String insertEdgeIn = String.format(
+            "INSERT INTO %s (OWNER_VERTEX, DIRECTION, LABEL, SUB_LABEL, SORT_VALUES, OTHER_VERTEX, PROPERTIES, EXPIRED_TIME) VALUES ('target_vertex', 1, 1, 0, '', 'test_vertex', '{\"weight\":1.0}', 0)",
+            edgeInTable
+        );
+        session.execute(insertEdgeIn);
+
+        // Verify data exists by querying
+        String selectVertex = String.format("SELECT * FROM %s WHERE ID = 'test_vertex'", vertexTable);
+        ResultSetWrapper vResult = session.select(selectVertex);
+        Assert.assertTrue("vertex data should exist", vResult.next());
+        vResult.close();
+        
+        String selectEdgeOut = String.format("SELECT * FROM %s WHERE OWNER_VERTEX = 'test_vertex' AND DIRECTION = 0", edgeOutTable);
+        ResultSetWrapper oeResult = session.select(selectEdgeOut);
+        Assert.assertTrue("out edge data should exist", oeResult.next());
+        oeResult.close();
+        
+        String selectEdgeIn = String.format("SELECT * FROM %s WHERE OWNER_VERTEX = 'target_vertex' AND DIRECTION = 1", edgeInTable);
+        ResultSetWrapper ieResult = session.select(selectEdgeIn);
+        Assert.assertTrue("in edge data should exist", ieResult.next());
+        ieResult.close();
+
+        // Execute truncate operation, clears all graph data but preserves system tables
         this.provider.truncate();
-        String afterInitVersion = systemStore.storedVersion();
-        Assert.assertNotNull(beforeVersion);
-        Assert.assertNotNull(afterInitVersion);
-        Assert.assertEquals(beforeVersion, afterInitVersion);
+
+        // Verify system version remains unchanged after truncation
+        String afterVersion = systemStore.storedVersion();
+        Assert.assertNotNull("System metadata version should exist", afterVersion);
+        Assert.assertEquals("System metadata version should remain unchanged after truncation", beforeVersion, afterVersion);
+
+        // Verify data has been cleared
+        vResult = session.select(selectVertex);
+        Assert.assertFalse("vertex data should not exist", vResult.next());
+        vResult.close();
+        
+        oeResult = session.select(selectEdgeOut);
+        Assert.assertFalse("out edge data should not exist", oeResult.next());
+        oeResult.close();
+        
+        ieResult = session.select(selectEdgeIn);
+        Assert.assertFalse("in edge data should not exist", ieResult.next());
+        ieResult.close();
     }
 }