#301 - MySQL specific issue - java.sql.SQLException: Streaming result…

… set com.mysql.jdbc.RowDataDynamic@3ef4415f is still active. No statements may be issued when any streaming result sets a re open and in use on a given connection. Ensure that you have called .close() on any active streaming result sets before attempting more queries

src/main/java/com/avaje/ebean/config/dbplatform/DatabasePlatform.java

@@ -39,6 +39,12 @@ public enum OnQueryOnly {
     COMMIT
   }
 
+
+  /**
+   * Set to true for MySql, no other jdbc drivers need this workaround.
+   */
+  protected boolean useExtraTransactionOnIterateSecondaryQueries;
+
   /**
    * The behaviour used when ending a read only transaction at read committed isolation level.
    */
@@ -153,6 +159,17 @@ public String getName() {
     return name;
   }
 
+  /**
+   * Return true if the JDBC driver does not allow additional queries to execute
+   * when a resultSet is being 'streamed' as is the case with findEach() etc.
+   * <p>
+   * Honestly, this is a workaround for a stupid MySql JDBC driver limitation.
+   * </p>
+   */
+  public boolean useExtraTransactionOnIterateSecondaryQueries() {
+    return useExtraTransactionOnIterateSecondaryQueries;
+  }
+
   /**
    * Return a DB Sequence based IdGenerator.
    * 

src/main/java/com/avaje/ebean/config/dbplatform/MySqlPlatform.java

@@ -20,6 +20,7 @@ public class MySqlPlatform extends DatabasePlatform {
   public MySqlPlatform() {
     super();
     this.name = "mysql";
+    this.useExtraTransactionOnIterateSecondaryQueries = true;
     this.likeClause = "like ? escape''";
     this.selectCountWithAlias = true;
     this.dbEncrypt = new MySqlDbEncrypt();

src/main/java/com/avaje/ebeaninternal/api/LoadRequest.java

@@ -48,4 +48,11 @@ public Transaction getTransaction() {
 		return transaction;
 	}
 
+	/**
+	 * Return true if the parent query is a findIterate() type query.
+	 * So one of - findIterate(), findEach(), findEachWhile() or findVisit().
+	 */
+	public boolean isParentFindIterate() {
+		return parentRequest != null && parentRequest.getQuery().getType() == SpiQuery.Type.ITERATE;
+	}
 }

src/main/java/com/avaje/ebeaninternal/api/SpiQuery.java

@@ -51,6 +51,11 @@ enum Type {
      */
     BEAN,
 
+    /**
+     * Find iterate type query - findEach(), findIterate() etc.
+     */
+    ITERATE,
+
     /**
      * Find returning a List.
      */

src/main/java/com/avaje/ebeaninternal/server/core/DefaultBeanLoader.java

@@ -5,6 +5,7 @@
 
 import javax.persistence.EntityNotFoundException;
 
+import com.avaje.ebeaninternal.api.*;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -15,11 +16,6 @@
 import com.avaje.ebean.bean.EntityBeanIntercept;
 import com.avaje.ebean.bean.ObjectGraphNode;
 import com.avaje.ebean.bean.PersistenceContext;
-import com.avaje.ebeaninternal.api.LoadBeanBuffer;
-import com.avaje.ebeaninternal.api.LoadBeanRequest;
-import com.avaje.ebeaninternal.api.LoadManyRequest;
-import com.avaje.ebeaninternal.api.LoadManyBuffer;
-import com.avaje.ebeaninternal.api.SpiQuery;
 import com.avaje.ebeaninternal.api.SpiQuery.Mode;
 import com.avaje.ebeaninternal.server.deploy.BeanDescriptor;
 import com.avaje.ebeaninternal.server.deploy.BeanPropertyAssocMany;
@@ -36,8 +32,11 @@ public class DefaultBeanLoader {
 
   private final DefaultServer server;
 
+  private final boolean onIterateUseExtraTxn;
+
   protected DefaultBeanLoader(DefaultServer server) {
     this.server = server;
+    this.onIterateUseExtraTxn = server.getDatabasePlatform().useExtraTransactionOnIterateSecondaryQueries();
   }
 
   /**
@@ -143,7 +142,17 @@ public void loadMany(LoadManyRequest loadRequest) {
       query.select(many.getTargetIdProperty());
     }
 
-    server.findList(query, loadRequest.getTransaction());
+    if (onIterateUseExtraTxn && loadRequest.isParentFindIterate()) {
+      // MySql - we need a different transaction to execute the secondary query
+      SpiTransaction extraTxn = server.createQueryTransaction();
+      try {
+        server.findList(query, extraTxn);
+      } finally {
+        extraTxn.end();
+      }
+    } else {
+      server.findList(query, loadRequest.getTransaction());
+    }
 
     // check for BeanCollection's that where never processed
     // in the +query or +lazy load due to no rows (predicates)
@@ -332,7 +341,18 @@ public void loadBean(LoadBeanRequest loadRequest) {
       query.where().idIn(idList);
     }
 
-    List<?> list = server.findList(query, loadRequest.getTransaction());
+    List<?> list;
+    if (onIterateUseExtraTxn && loadRequest.isParentFindIterate()) {
+      // MySql - we need a different transaction to execute the secondary query
+      SpiTransaction extraTxn = server.createQueryTransaction();
+      try {
+        list = server.findList(query, extraTxn);
+      } finally {
+        extraTxn.end();
+      }
+    } else {
+      list = server.findList(query, loadRequest.getTransaction());
+    }
 
     if (loadRequest.isLoadCache()) {
       for (int i = 0; i < list.size(); i++) {

src/main/java/com/avaje/ebeaninternal/server/core/DefaultServer.java

@@ -1318,7 +1318,7 @@ public <T> PagedList<T> findPagedList(Query<T> query, Transaction transaction, i
 
   public <T> void findVisit(Query<T> query, QueryResultVisitor<T> visitor, Transaction t) {
 
-    SpiOrmQueryRequest<T> request = createQueryRequest(Type.LIST, query, t);
+    SpiOrmQueryRequest<T> request = createQueryRequest(Type.ITERATE, query, t);
 
     request.initTransIfRequired();
     request.findVisit(visitor);
@@ -1327,7 +1327,7 @@ public <T> void findVisit(Query<T> query, QueryResultVisitor<T> visitor, Transac
 
   public <T> void findEach(Query<T> query, QueryEachConsumer<T> consumer, Transaction t) {
 
-    SpiOrmQueryRequest<T> request = createQueryRequest(Type.LIST, query, t);
+    SpiOrmQueryRequest<T> request = createQueryRequest(Type.ITERATE, query, t);
 
     request.initTransIfRequired();
     request.findEach(consumer);
@@ -1336,7 +1336,7 @@ public <T> void findEach(Query<T> query, QueryEachConsumer<T> consumer, Transact
 
   public <T> void findEachWhile(Query<T> query, QueryEachWhileConsumer<T> consumer, Transaction t) {
 
-    SpiOrmQueryRequest<T> request = createQueryRequest(Type.LIST, query, t);
+    SpiOrmQueryRequest<T> request = createQueryRequest(Type.ITERATE, query, t);
 
     request.initTransIfRequired();
     request.findEachWhile(consumer);
@@ -1345,7 +1345,7 @@ public <T> void findEachWhile(Query<T> query, QueryEachWhileConsumer<T> consumer
 
   public <T> QueryIterator<T> findIterate(Query<T> query, Transaction t) {
 
-    SpiOrmQueryRequest<T> request = createQueryRequest(Type.LIST, query, t);
+    SpiOrmQueryRequest<T> request = createQueryRequest(Type.ITERATE, query, t);
 
     try {
       request.initTransIfRequired();