[#454] Added CTE / LIMIT / OFFSET integration tests

jOOQ-test/src/test/java/org/jooq/test/all/testcases/CTETests.java

@@ -236,10 +236,6 @@ extends BaseTest<A, AP, B, S, B2S, BS, L, X, DATE, BOOL, D, T, U, UU, I, IPK, T7
         assertEquals(String.class, result1.field(1).getType());
         assertEquals(1, (int) result1.get(0).getValue(0, Integer.class));
         assertEquals("a", result1.getValue(0, 1));
-
-        // TODO: Test CTE with UNIONs (may not work due to #1658)
-        // TODO: Test CTE with LIMIT .. OFFSET (may not work due to ROWNUM emulation, etc)
-        // TODO: Test CTE with complex subqueries
     }
 
     public void testRecursiveCTESimple() throws Exception {
@@ -343,4 +339,58 @@ extends BaseTest<A, AP, B, S, B2S, BS, L, X, DATE, BOOL, D, T, U, UU, I, IPK, T7
                         .collect(toList()),
                      result.getValues(3));
     }
+
+    public void testCTEWithLimit() throws Exception {
+        assumeFamilyNotIn(CUBRID, DERBY, H2, MARIADB, MYSQL, SQLITE);
+
+        CommonTableExpression<Record3<String, String, Integer>> t1 = name("t1").as(
+            select(TAuthor_FIRST_NAME(), TAuthor_LAST_NAME(), TBook_ID())
+            .from(TAuthor())
+            .join(TBook())
+            .on(TBook_AUTHOR_ID().eq(TAuthor_ID()))
+            .orderBy(TBook_ID())
+            .limit(3)
+        );
+
+        Result<Record> result =
+        create().with(t1)
+                .select(t1.fields())
+                .from(t1)
+                .orderBy(t1.field(2).desc())
+                .limit(2)
+                .fetch();
+
+        assertEquals(2, result.size());
+        assertEquals(asList("Paulo", "George"), result.getValues(0));
+        assertEquals(asList("Coelho", "Orwell"), result.getValues(1));
+        assertEquals(asList(3, 2), result.getValues(2, int.class));
+    }
+
+    public void testCTEWithLimitOffset() throws Exception {
+        assumeFamilyNotIn(CUBRID, DERBY, H2, MARIADB, MYSQL, SQLITE);
+
+        CommonTableExpression<Record3<String, String, Integer>> t1 = name("t1").as(
+            select(TAuthor_FIRST_NAME(), TAuthor_LAST_NAME(), TBook_ID())
+            .from(TAuthor())
+            .join(TBook())
+            .on(TBook_AUTHOR_ID().eq(TAuthor_ID()))
+            .orderBy(TBook_ID())
+            .limit(3)
+            .offset(1)
+        );
+
+        Result<Record> result =
+        create().with(t1)
+                .select(t1.fields())
+                .from(t1)
+                .orderBy(t1.field(2).desc())
+                .limit(2)
+                .offset(1)
+                .fetch();
+
+        assertEquals(2, result.size());
+        assertEquals(asList("Paulo", "George"), result.getValues(0));
+        assertEquals(asList("Coelho", "Orwell"), result.getValues(1));
+        assertEquals(asList(3, 2), result.getValues(2, int.class));
+    }
 }

jOOQ-test/src/test/java/org/jooq/test/jOOQAbstractTest.java

@@ -2267,6 +2267,16 @@ public abstract class jOOQAbstractTest<
         new CTETests(this).testRecursiveCTEMultiple();
     }
 
+    @Test
+    public void testCTEWithLimit() throws Exception {
+        new CTETests(this).testCTEWithLimit();
+    }
+
+    @Test
+    public void testCTEWithLimitOffset() throws Exception {
+        new CTETests(this).testCTEWithLimitOffset();
+    }
+
     @Test
     public void testJoinDuplicateFieldNames() throws Exception {
         new JoinTests(this).testJoinDuplicateFieldNames();

jOOQ/src/main/java/org/jooq/Name.java

@@ -70,6 +70,15 @@ public interface Name extends QueryPart {
      */
     WindowDefinition as(WindowSpecification window);
 
+    /**
+     * Specify a subselect to refer to by the <code>Name</code> to form a common
+     * table expression.
+     * <p>
+     * Column names are implicitly inherited from the <code>SELECT</code>
+     * statement.
+     */
+    <R extends Record> CommonTableExpression<R> as(Select<R> select);
+
     /**
      * Add a list of fields to this name to make this name a
      * {@link DerivedColumnList}.

jOOQ/src/main/java/org/jooq/impl/NameImpl.java

@@ -43,9 +43,12 @@ package org.jooq.impl;
 import java.util.Arrays;
 
 import org.jooq.Clause;
+import org.jooq.CommonTableExpression;
 import org.jooq.Context;
 import org.jooq.DerivedColumnList;
 import org.jooq.Name;
+import org.jooq.Record;
+import org.jooq.Select;
 import org.jooq.WindowDefinition;
 import org.jooq.WindowSpecification;
 import org.jooq.tools.StringUtils;
@@ -95,6 +98,11 @@ class NameImpl extends AbstractQueryPart implements Name {
         return new WindowDefinitionImpl(this, window);
     }
 
+    @Override
+    public final <R extends Record> CommonTableExpression<R> as(Select<R> select) {
+        return fields(new String[0]).as(select);
+    }
+
     @Override
     public final DerivedColumnList fields(String... fieldNames) {
         if (qualifiedName.length != 1)