#1841 - SqlServer findCount with @Aggregation gives SQLException:No column name was specified for column 2 of 'c'

src/main/java/io/ebean/config/dbplatform/DatabasePlatform.java

@@ -148,8 +148,6 @@ public class DatabasePlatform {
 
   protected String columnAliasPrefix = "c";
 
-  protected String tableAliasPlaceHolder = "${ta}";
-
   /**
    * Use a BackTick ` at the beginning and end of table or column names that you
    * want to use quoted identifiers for. The backticks get converted to the
@@ -183,6 +181,7 @@ public class DatabasePlatform {
   protected boolean idInExpandedForm;
 
   protected boolean selectCountWithAlias;
+  protected boolean selectCountWithColumnAlias;
 
   /**
    * If set then use the FORWARD ONLY hint when creating ResultSets for
@@ -478,20 +477,6 @@ public class DatabasePlatform {
     this.columnAliasPrefix = columnAliasPrefix;
   }
 
-  /**
-   * Return the table alias placeholder.
-   */
-  public String getTableAliasPlaceHolder() {
-    return tableAliasPlaceHolder;
-  }
-
-  /**
-   * Set the table alias placeholder.
-   */
-  public void setTableAliasPlaceHolder(String tableAliasPlaceHolder) {
-    this.tableAliasPlaceHolder = tableAliasPlaceHolder;
-  }
-
   /**
    * Return the close quote for quoted identifiers.
    */
@@ -684,6 +669,14 @@ public class DatabasePlatform {
     return selectCountWithAlias;
   }
 
+  /**
+   * Return true if select count with subquery needs column alias (SQL Server).
+   */
+  public boolean isSelectCountWithColumnAlias() {
+    return selectCountWithColumnAlias;
+  }
+
+
   public String completeSql(String sql, Query<?> query) {
     if (query.isForUpdate()) {
       sql = withForUpdate(sql, query.getForUpdateMode());

src/main/java/io/ebean/config/dbplatform/sqlserver/SqlServerBasePlatform.java

@@ -28,6 +28,7 @@ abstract class SqlServerBasePlatform extends DatabasePlatform {
     this.persistBatchOnCascade = PersistBatch.NONE;
     this.idInExpandedForm = true;
     this.selectCountWithAlias = true;
+    this.selectCountWithColumnAlias = true;
     this.sqlLimiter = new SqlServerSqlLimiter();
     this.basicSqlLimiter = new SqlServerBasicSqlLimiter();
     this.historySupport = new SqlServerHistorySupport();

src/main/java/io/ebeaninternal/server/query/CQueryBuilder.java

@@ -43,9 +43,7 @@ import java.util.List;
  */
 class CQueryBuilder {
 
-  final String tableAliasPlaceHolder;
-  final String columnAliasPrefix;
-
+  private final String columnAliasPrefix;
   private final SqlLimiter sqlLimiter;
   private final CQueryBuilderRawSql rawSqlHandler;
   private final Binder binder;
@@ -55,6 +53,7 @@ class CQueryBuilder {
   private final CQueryHistorySupport historySupport;
   private final CQueryDraftSupport draftSupport;
   private final DatabasePlatform dbPlatform;
+  private final boolean selectCountWithColumnAlias;
 
   /**
    * Create the SqlGenSelect.
@@ -64,11 +63,11 @@ class CQueryBuilder {
     this.binder = binder;
     this.draftSupport = draftSupport;
     this.historySupport = historySupport;
-    this.tableAliasPlaceHolder = dbPlatform.getTableAliasPlaceHolder();
     this.columnAliasPrefix = dbPlatform.getColumnAliasPrefix();
     this.sqlLimiter = dbPlatform.getSqlLimiter();
     this.rawSqlHandler = new CQueryBuilderRawSql(sqlLimiter, dbPlatform);
     this.selectCountWithAlias = dbPlatform.isSelectCountWithAlias();
+    this.selectCountWithColumnAlias = dbPlatform.isSelectCountWithColumnAlias();
   }
 
   /**
@@ -86,7 +85,6 @@ class CQueryBuilder {
       sb.append(".");
       sb.append(token.trim());
     }
-
     return sb.toString();
   }
 
@@ -273,7 +271,7 @@ class CQueryBuilder {
 
     predicates.prepare(true);
 
-    SqlTree sqlTree = createSqlTree(request, predicates);
+    SqlTree sqlTree = createSqlTree(request, predicates, selectCountWithColumnAlias && withAgg);
     if (SpiQuery.TemporalMode.CURRENT == query.getTemporalMode()) {
       sqlTree.addSoftDeletePredicate(query);
     }
@@ -399,6 +397,10 @@ class CQueryBuilder {
    * </p>
    */
   private SqlTree createSqlTree(OrmQueryRequest<?> request, CQueryPredicates predicates) {
+    return createSqlTree(request, predicates, false);
+  }
+
+  private SqlTree createSqlTree(OrmQueryRequest<?> request, CQueryPredicates predicates, boolean forceColumnAlias) {
 
     if (request.isNativeSql()) {
       return createNativeSqlTree(request, predicates);
@@ -406,7 +408,8 @@ class CQueryBuilder {
     if (request.isRawSql()) {
       return createRawSqlSqlTree(request, predicates);
     }
-    return new SqlTreeBuilder(this, request, predicates).build();
+    String colAliasPrefix = forceColumnAlias ? "c" : columnAliasPrefix;
+    return new SqlTreeBuilder(colAliasPrefix, this, request, predicates).build();
   }
 
   private String nativeQueryPaging(SpiQuery<?> query, String sql) {

src/main/java/io/ebeaninternal/server/query/DefaultDbSqlContext.java

@@ -16,7 +16,7 @@ class DefaultDbSqlContext implements DbSqlContext {
   private static final String PERIOD = ".";
   private static final int STRING_BUILDER_INITIAL_CAPACITY = 140;
 
-  private final String tableAliasPlaceHolder;
+  private static final String tableAliasPlaceHolder = "${ta}";
 
   private final String columnAliasPrefix;
 
@@ -56,14 +56,11 @@ class DefaultDbSqlContext implements DbSqlContext {
   /**
    * Construct for SELECT clause (with column alias settings).
    */
-  DefaultDbSqlContext(SqlTreeAlias alias, CQueryBuilder builder,
-                      boolean alwaysUseColumnAlias, CQueryHistorySupport historySupport,
+  DefaultDbSqlContext(SqlTreeAlias alias, String columnAliasPrefix, CQueryHistorySupport historySupport,
                       CQueryDraftSupport draftSupport, String fromForUpdate) {
-
     this.alias = alias;
-    this.tableAliasPlaceHolder = builder.tableAliasPlaceHolder;
-    this.columnAliasPrefix = builder.columnAliasPrefix;
-    this.useColumnAlias = columnAliasPrefix != null && alwaysUseColumnAlias;
+    this.columnAliasPrefix = columnAliasPrefix;
+    this.useColumnAlias = columnAliasPrefix != null;
     this.draftSupport = draftSupport;
     this.historySupport = historySupport;
     this.historyQuery = (historySupport != null);

src/main/java/io/ebeaninternal/server/query/SqlTreeBuilder.java

@@ -96,7 +96,7 @@ public final class SqlTreeBuilder {
    * support the where and/or order by clause. If so these extra joins are added
    * to the root node.
    */
-  SqlTreeBuilder(CQueryBuilder builder, OrmQueryRequest<?> request, CQueryPredicates predicates) {
+  SqlTreeBuilder(String columnAliasPrefix, CQueryBuilder builder, OrmQueryRequest<?> request, CQueryPredicates predicates) {
 
     this.rawSql = false;
     this.rawNoId = false;
@@ -116,7 +116,8 @@ public final class SqlTreeBuilder {
     String fromForUpdate = builder.fromForUpdate(query);
     CQueryHistorySupport historySupport = builder.getHistorySupport(query);
     CQueryDraftSupport draftSupport = builder.getDraftSupport(query);
-    this.ctx = new DefaultDbSqlContext(alias, builder, !subQuery, historySupport, draftSupport, fromForUpdate);
+    String colAlias = subQuery ? null : columnAliasPrefix;
+    this.ctx = new DefaultDbSqlContext(alias, colAlias, historySupport, draftSupport, fromForUpdate);
   }
 
   /**