Distinguish between exists and in subquery

ebean-core/src/main/java/io/ebeaninternal/api/SpiEbeanServer.java

@@ -8,6 +8,7 @@ import io.ebean.config.dbplatform.DatabasePlatform;
 import io.ebean.event.readaudit.ReadAuditLogger;
 import io.ebean.event.readaudit.ReadAuditPrepare;
 import io.ebean.meta.MetricVisitor;
+import io.ebeaninternal.api.SpiQuery.Type;
 import io.ebeaninternal.server.core.SpiResultSet;
 import io.ebeaninternal.server.core.timezone.DataTimeZone;
 import io.ebeaninternal.server.deploy.BeanDescriptor;
@@ -149,7 +150,7 @@ public interface SpiEbeanServer extends ExtendedServer, EbeanServer, BeanCollect
   /**
    * Compile a query.
    */
-  <T> CQuery<T> compileQuery(Query<T> query, Transaction t);
+  <T> CQuery<T> compileQuery(Type type, Query<T> query, Transaction t);
 
   /**
    * Execute the findId's query but without copying the query.

ebean-core/src/main/java/io/ebeaninternal/api/SpiQuery.java

@@ -92,9 +92,14 @@ public interface SpiQuery<T> extends Query<T>, SpiQueryFetch, TxnProfileEventCod
     COUNT(FIND_COUNT, "findCount"),
 
     /**
-     * A subquery used as part of a where clause.
+     * A subquery used as part of an exists where clause.
      */
-    SUBQUERY(FIND_SUBQUERY, "subquery"),
+    SQ_EXISTS(FIND_SUBQUERY, "sqExists"),
+
+    /**
+     * A subquery used as part of an in where clause.
+     */
+    SQ_IN(FIND_SUBQUERY, "sqIn"),
 
     /**
      * Delete query.

ebean-core/src/main/java/io/ebeaninternal/server/core/DefaultServer.java

@@ -526,8 +526,8 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
    * Compile a query. Only valid for ORM queries.
    */
   @Override
-  public <T> CQuery<T> compileQuery(Query<T> query, Transaction t) {
-    SpiOrmQueryRequest<T> qr = createQueryRequest(Type.SUBQUERY, query, t);
+  public <T> CQuery<T> compileQuery(Type type, Query<T> query, Transaction t) {
+    SpiOrmQueryRequest<T> qr = createQueryRequest(type, query, t);
     OrmQueryRequest<T> orm = (OrmQueryRequest<T>) qr;
     return cqueryEngine.buildQuery(orm);
   }

ebean-core/src/main/java/io/ebeaninternal/server/expression/ExistsQueryExpression.java

@@ -9,6 +9,7 @@ import io.ebeaninternal.api.SpiExpression;
 import io.ebeaninternal.api.SpiExpressionRequest;
 import io.ebeaninternal.api.SpiExpressionValidation;
 import io.ebeaninternal.api.SpiQuery;
+import io.ebeaninternal.api.SpiQuery.Type;
 import io.ebeaninternal.server.deploy.BeanDescriptor;
 import io.ebeaninternal.server.query.CQuery;
 
@@ -82,7 +83,7 @@ class ExistsQueryExpression implements SpiExpression, UnsupportedDocStoreExpress
    */
   protected CQuery<?> compileSubQuery(BeanQueryRequest<?> queryRequest) {
     SpiEbeanServer ebeanServer = (SpiEbeanServer) queryRequest.getEbeanServer();
-    return ebeanServer.compileQuery(subQuery, queryRequest.getTransaction());
+    return ebeanServer.compileQuery(Type.SQ_EXISTS, subQuery, queryRequest.getTransaction());
   }
 
   @Override

ebean-core/src/main/java/io/ebeaninternal/server/expression/InQueryExpression.java

@@ -6,6 +6,7 @@ import io.ebeaninternal.api.SpiEbeanServer;
 import io.ebeaninternal.api.SpiExpression;
 import io.ebeaninternal.api.SpiExpressionRequest;
 import io.ebeaninternal.api.SpiQuery;
+import io.ebeaninternal.api.SpiQuery.Type;
 import io.ebeaninternal.server.query.CQuery;
 
 import java.io.IOException;
@@ -69,7 +70,7 @@ class InQueryExpression extends AbstractExpression implements UnsupportedDocStor
   private CQuery<?> compileSubQuery(BeanQueryRequest<?> queryRequest) {
 
     SpiEbeanServer ebeanServer = (SpiEbeanServer) queryRequest.getEbeanServer();
-    return ebeanServer.compileQuery(subQuery, queryRequest.getTransaction());
+    return ebeanServer.compileQuery(Type.SQ_IN, subQuery, queryRequest.getTransaction());
   }
 
   @Override

ebean-core/src/main/java/io/ebeaninternal/server/query/SqlTree.java

@@ -101,6 +101,7 @@ class SqlTree {
    * Return the String for the actual SQL.
    */
   String getSelectSql() {
+    assert selectSql != null : "selectSql was null";
     return selectSql;
   }
 

ebean-core/src/main/java/io/ebeaninternal/server/query/SqlTreeBuilder.java

@@ -102,7 +102,11 @@ public final class SqlTreeBuilder {
     this.query = request.getQuery();
     this.temporalMode = SpiQuery.TemporalMode.of(query);
     this.disableLazyLoad = query.isDisableLazyLoading();
-    this.subQuery = Type.SUBQUERY == query.getType() || Type.ID_LIST == query.getType() || Type.DELETE == query.getType() || query.isCountDistinct();
+    this.subQuery = Type.SQ_EXISTS == query.getType()
+        || Type.SQ_IN == query.getType() 
+        || Type.ID_LIST == query.getType() 
+        || Type.DELETE == query.getType() 
+        || query.isCountDistinct();
     this.includeJoin = query.getM2mIncludeJoin();
     this.manyWhereJoins = query.getManyWhereJoins();
     this.queryDetail = query.getDetail();
@@ -146,6 +150,10 @@ public final class SqlTreeBuilder {
     if (rawSql) {
       return "Not Used";
     }
+    if (query.getType() ==Type.SQ_EXISTS) {
+      // effective query is "where exists (select 1 from ...)"
+      return "1";
+    }
     rootNode.appendSelect(ctx, subQuery);
     return trimComma(ctx.getContent());
   }

ebean-core/src/main/java/io/ebeaninternal/server/querydefn/DefaultOrmQuery.java

@@ -565,7 +565,8 @@ public class DefaultOrmQuery<T> extends AbstractQuery implements SpiQuery<T> {
    * Limit the number of fetch joins to Many properties, mark as query joins as needed.
    */
   private void markQueryJoins() {
-    detail.markQueryJoins(beanDescriptor, lazyLoadManyPath, isAllowOneManyFetch(), type != Type.ATTRIBUTE && type != Type.SUBQUERY);
+    detail.markQueryJoins(beanDescriptor, lazyLoadManyPath, isAllowOneManyFetch(), 
+        type != Type.ATTRIBUTE && type != Type.SQ_EXISTS && type != Type.SQ_IN);
   }
 
   private boolean isAllowOneManyFetch() {
@@ -578,7 +579,7 @@ public class DefaultOrmQuery<T> extends AbstractQuery implements SpiQuery<T> {
 
   @Override
   public void setDefaultSelectClause() {
-    if (type != Type.ATTRIBUTE && type != Type.SUBQUERY) {
+    if (type != Type.ATTRIBUTE && type != Type.SQ_EXISTS && type != Type.SQ_IN) {
       detail.setDefaultSelectClause(beanDescriptor);
     } else if (!detail.hasSelectClause()) {
       // explicit empty select when single attribute query on non-root fetch path