diff --git a/src/test/kotlin/kestrel/store/sql/DiskExecutorTest.kt b/src/test/kotlin/kestrel/store/sql/DiskExecutorTest.kt
index 6fc2ab0..8ad9d06 100644
--- a/src/test/kotlin/kestrel/store/sql/DiskExecutorTest.kt
+++ b/src/test/kotlin/kestrel/store/sql/DiskExecutorTest.kt
@@ -310,3 +310,166 @@ class DiskExecutorTest {
         run("INSERT INTO orders VALUES (1, 1, 100), (2, 1, 50), (3, 2, 200)")
     }
 
+    // Adds an order referencing a customer id that does not exist, so RIGHT/FULL JOIN has an
+    // unmatched *right* row to pad with NULLs on top of grace's unmatched left row from seedOrders.
+    private fun Database.seedOrdersWithOrphan() {
+        seedOrders()
+        run("INSERT INTO orders VALUES (4, 99, 999)")
+    }
+
+    @Test
+    fun rightJoinPadsUnmatchedRightRowsWithNulls() {
+        val db = newDatabase()
+        db.seedOrdersWithOrphan()
+        val result = db.select(
+            "SELECT customers.name, orders.amount FROM customers RIGHT JOIN orders ON customers.id = orders.customer_id ORDER BY orders.id"
+        )
+        assertEquals(
+            listOf(
+                listOf(text("ada"), int(100)),
+                listOf(text("ada"), int(50)),
+                listOf(text("linus"), int(200)),
+                listOf(Value.NullValue, int(999))
+            ),
+            result.rows
+        )
+    }
+
+    @Test
+    fun fullJoinKeepsBothUnmatchedLeftAndRightRows() {
+        val db = newDatabase()
+        db.seedOrdersWithOrphan()
+        val result = db.select(
+            "SELECT customers.name, orders.amount FROM customers FULL JOIN orders ON customers.id = orders.customer_id"
+        )
+        assertEquals(
+            setOf(
+                listOf(text("ada"), int(100)),
+                listOf(text("ada"), int(50)),
+                listOf(text("linus"), int(200)),
+                listOf(text("grace"), Value.NullValue),
+                listOf(Value.NullValue, int(999))
+            ),
+            result.rows.toSet()
+        )
+        assertEquals(5, result.rows.size)
+    }
+
+    @Test
+    fun crossJoinProducesTheFullCartesianProductWithNoOnClause() {
+        val db = newDatabase()
+        db.run("CREATE TABLE colors (name TEXT)")
+        db.run("CREATE TABLE sizes (label TEXT)")
+        db.run("INSERT INTO colors VALUES ('red'), ('blue')")
+        db.run("INSERT INTO sizes VALUES ('s'), ('m')")
+        val result = db.select("SELECT colors.name, sizes.label FROM colors CROSS JOIN sizes ORDER BY colors.name, sizes.label")
+        assertEquals(
+            listOf(
+                listOf(text("blue"), text("m")), listOf(text("blue"), text("s")),
+                listOf(text("red"), text("m")), listOf(text("red"), text("s"))
+            ),
+            result.rows
+        )
+    }
+
+    @Test
+    fun rightOuterAndFullOuterJoinSpellingsAreAccepted() {
+        val db = newDatabase()
+        db.seedOrders()
+        val right = db.select(
+            "SELECT customers.name FROM customers RIGHT OUTER JOIN orders ON customers.id = orders.customer_id ORDER BY orders.id"
+        )
+        assertEquals(listOf(listOf(text("ada")), listOf(text("ada")), listOf(text("linus"))), right.rows)
+        val full = db.select(
+            "SELECT customers.name FROM customers FULL OUTER JOIN orders ON customers.id = orders.customer_id ORDER BY customers.id"
+        )
+        assertEquals(4, full.rows.size)
+    }
+
+    @Test
+    fun innerJoinCombinesMatchingRowsAndDropsUnmatchedLeftRows() {
+        val db = newDatabase()
+        db.seedOrders()
+        val result = db.select(
+            "SELECT customers.name, orders.amount FROM customers JOIN orders ON customers.id = orders.customer_id ORDER BY orders.id"
+        )
+        assertEquals(listOf("name", "amount"), result.columns)
+        assertEquals(
+            listOf(listOf(text("ada"), int(100)), listOf(text("ada"), int(50)), listOf(text("linus"), int(200))),
+            result.rows
+        )
+    }
+
+    @Test
+    fun leftJoinPadsUnmatchedLeftRowsWithNulls() {
+        val db = newDatabase()
+        db.seedOrders()
+        val result = db.select(
+            "SELECT customers.name, orders.amount FROM customers LEFT JOIN orders ON customers.id = orders.customer_id ORDER BY customers.id, orders.id"
+        )
+        assertEquals(
+            listOf(
+                listOf(text("ada"), int(100)),
+                listOf(text("ada"), int(50)),
+                listOf(text("linus"), int(200)),
+                listOf(text("grace"), Value.NullValue)
+            ),
+            result.rows
+        )
+    }
+
+    @Test
+    fun joinUsesTableAliasesToQualifyColumnsWithTheSameName() {
+        val db = newDatabase()
+        db.run("CREATE TABLE a (id INTEGER PRIMARY KEY, tag TEXT NOT NULL)")
+        db.run("CREATE TABLE b (id INTEGER PRIMARY KEY, tag TEXT NOT NULL)")
+        db.run("INSERT INTO a VALUES (1, 'left')")
+        db.run("INSERT INTO b VALUES (1, 'right')")
+        val result = db.select("SELECT x.tag, y.tag FROM a x JOIN b y ON x.id = y.id")
+        assertEquals(listOf(listOf(text("left"), text("right"))), result.rows)
+    }
+
+    @Test
+    fun anUnqualifiedColumnPresentInBothJoinedTablesIsRejectedAsAmbiguous() {
+        val db = newDatabase()
+        db.run("CREATE TABLE a (id INTEGER PRIMARY KEY)")
+        db.run("CREATE TABLE b (id INTEGER PRIMARY KEY)")
+        db.run("INSERT INTO a VALUES (1)")
+        db.run("INSERT INTO b VALUES (1)")
+        val failure = assertFailsWith<DiskExecutorException> { db.select("SELECT id FROM a JOIN b ON a.id = b.id") }
+        assertTrue(failure.message!!.contains("ambiguous"))
+    }
+
+    @Test
+    fun aDuplicateTableAliasAcrossJoinedSourcesIsRejected() {
+        val db = newDatabase()
+        db.run("CREATE TABLE a (id INTEGER PRIMARY KEY)")
+        val failure = assertFailsWith<DiskExecutorException> { db.select("SELECT * FROM a x JOIN a x ON x.id = x.id") }
+        assertTrue(failure.message!!.contains("duplicate table alias"))
+    }
+
+    @Test
+    fun joiningThreeTablesChainsLeftToRight() {
+        val db = newDatabase()
+        db.seedOrders()
+        db.run("CREATE TABLE shipments (id INTEGER PRIMARY KEY, order_id INTEGER NOT NULL, carrier TEXT NOT NULL)")
+        db.run("INSERT INTO shipments VALUES (1, 1, 'ups')")
+        val result = db.select(
+            "SELECT customers.name, orders.amount, shipments.carrier " +
+                "FROM customers JOIN orders ON customers.id = orders.customer_id " +
+                "JOIN shipments ON orders.id = shipments.order_id"
+        )
+        assertEquals(listOf(listOf(text("ada"), int(100), text("ups"))), result.rows)
+    }
+
+    @Test
+    fun joinAgainstADerivedTableWorks() {
+        val db = newDatabase()
+        db.run("CREATE TABLE a (id INTEGER PRIMARY KEY, name TEXT NOT NULL)")
+        db.run("CREATE TABLE b (id INTEGER PRIMARY KEY)")
+        db.run("INSERT INTO a VALUES (1, 'ada'), (2, 'linus')")
+        db.run("INSERT INTO b VALUES (1)")
+        val result = db.select("SELECT a.name FROM a JOIN (SELECT id FROM b) sub ON a.id = sub.id")
+        assertEquals(listOf(listOf(text("ada"))), result.rows)
+    }
+