From 203341cf9d7fa67aa50bb3fe1b6d5c98a9c7814d Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Thu, 12 Mar 2020 11:57:25 +0100
Subject: [PATCH] [jOOQ/jOOQ#3035] INSERT .. RETURNING does not return any
 value in H2, when no AUTO_INCREMENT column is involved

---
 .../java/org/jooq/impl/AbstractDMLQuery.java  | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/jOOQ/src/main/java/org/jooq/impl/AbstractDMLQuery.java b/jOOQ/src/main/java/org/jooq/impl/AbstractDMLQuery.java
index 1b7bc443c8..f90fff9846 100644
--- a/jOOQ/src/main/java/org/jooq/impl/AbstractDMLQuery.java
+++ b/jOOQ/src/main/java/org/jooq/impl/AbstractDMLQuery.java
@@ -1198,17 +1198,22 @@ abstract class AbstractDMLQuery<R extends Record> extends AbstractRowCountQuery
     ) {
         if (values != null && values.length > 0) {
 
-            // This shouldn't be null, as relevant dialects should
-            // return empty generated keys ResultSet
-            if (table.getIdentity() != null) {
-                final Field<Object> field = (Field<Object>) table.getIdentity().getField();
+            // [#3035] Support identity columns and single column primary keys
+            final Field<?> identity =
+                  table.getIdentity() != null
+                ? (Field<Object>) table.getIdentity().getField()
+                : table.getPrimaryKey() != null && table.getPrimaryKey().getFields().size() == 1
+                ? table.getPrimaryKey().getFields().get(0)
+                : null;
+
+            if (identity != null) {
                 Object[] ids = new Object[values.length];
                 for (int i = 0; i < values.length; i++)
-                    ids[i] = field.getDataType().convert(values[i]);
+                    ids[i] = identity.getDataType().convert(values[i]);
 
                 // Only the IDENTITY value was requested. No need for an
                 // additional query
-                if (returningResolvedAsterisks.size() == 1 && new Fields<>(returningResolvedAsterisks).field(field) != null) {
+                if (returningResolvedAsterisks.size() == 1 && new Fields<>(returningResolvedAsterisks).field(identity) != null) {
                     for (final Object id : ids) {
                         ((Result) getResult()).add(
                         Tools.newRecord(
@@ -1237,7 +1242,7 @@ abstract class AbstractDMLQuery<R extends Record> extends AbstractRowCountQuery
                                         .from(table)
 
                                         // [#5050] [#9946] Table.getIdentity() doesn't produce aliased fields yet
-                                        .where(table.field(field).in(ids))
+                                        .where(table.field((Field) identity).in(ids))
                                         .fetch();
 
                     returnedResult.attach(originalConfiguration);