fix: re-select inserted default and generated values with a single SE…

…LECT

closes typeorm#6266

src/query-builder/ReturningResultsEntityUpdator.ts

@@ -117,26 +117,29 @@ export class ReturningResultsEntityUpdator {
         // for postgres and mssql we use returning/output statement to get values of inserted default and generated values
         // for other drivers we have to re-select this data from the database
         if (this.queryRunner.connection.driver.isReturningSqlSupported() === false && insertionColumns.length > 0) {
-            await Promise.all(entities.map(async (entity, entityIndex) => {
+            const entityIds = entities.map((entity) => {
                 const entityId = metadata.getEntityIdMap(entity)!;
-
-                // to select just inserted entity we need a criteria to select by.
-                // for newly inserted entities in drivers which do not support returning statement
-                // row identifier can only be an increment column
-                // (since its the only thing that can be generated by those databases)
-                // or (and) other primary key which is defined by a user and inserted value has it
-
-                const returningResult: any = await this.queryRunner.manager
-                    .createQueryBuilder()
-                    .select(metadata.primaryColumns.map(column => metadata.targetName + "." + column.propertyPath))
-                    .addSelect(insertionColumns.map(column => metadata.targetName + "." + column.propertyPath))
-                    .from(metadata.target, metadata.targetName)
-                    .where(entityId)
-                    .setOption("create-pojo") // use POJO because created object can contain default values, e.g. property = null and those properties maight be overridden by merge process
-                    .getOne();
-
-                this.queryRunner.manager.merge(metadata.target as any, generatedMaps[entityIndex], returningResult);
-            }));
+                return entityId;
+            });
+
+            // to select just inserted entities we need a criteria to select by.
+            // for newly inserted entities in drivers which do not support returning statement
+            // row identifier can only be an increment column
+            // (since its the only thing that can be generated by those databases)
+            // or (and) other primary key which is defined by a user and inserted value has it
+
+            const returningResult: any = await this.queryRunner.manager
+                .createQueryBuilder()
+                .select(metadata.primaryColumns.map(column => metadata.targetName + "." + column.propertyPath))
+                .addSelect(insertionColumns.map(column => metadata.targetName + "." + column.propertyPath))
+                .from(metadata.target, metadata.targetName)
+                .where(entityIds)
+                .setOption("create-pojo") // use POJO because created object can contain default values, e.g. property = null and those properties maight be overridden by merge process
+                .getMany();
+
+            entities.forEach((entity, entityIndex) => {
+                this.queryRunner.manager.merge(metadata.target as any, generatedMaps[entityIndex], returningResult[entityIndex]);
+            })
         }
 
         entities.forEach((entity, entityIndex) => {