Add Foreign Key ON DELETE SET NULL support for Cloud Spanner Avro tem…

v1/src/main/java/com/google/cloud/teleport/spanner/ddl/ForeignKey.java

@@ -38,9 +38,9 @@ public enum ReferentialAction {
     // Supported actions
     ON_DELETE_NO_ACTION("ON DELETE NO ACTION"),
     ON_DELETE_CASCADE("ON DELETE CASCADE"),
+    ON_DELETE_SET_NULL("ON DELETE SET NULL"),
     // Currently unsupported actions, listed here for completeness
     ON_DELETE_RESTRICT("ON DELETE RESTRICT"),
-    ON_DELETE_SET_NULL("ON DELETE SET NULL"),
     ON_DELETE_SET_DEFAULT("ON DELETE SET DEFAULT"),
     ON_UPDATE_NO_ACTION("ON UPDATE NO ACTION"),
     ON_UPDATE_CASCADE("ON UPDATE CASCADE"),
@@ -69,6 +69,8 @@ public static ReferentialAction getReferentialAction(String changeType, String a
             return ReferentialAction.ON_DELETE_CASCADE;
           case "NO ACTION":
             return ReferentialAction.ON_DELETE_NO_ACTION;
+          case "SET NULL":
+            return ReferentialAction.ON_DELETE_SET_NULL;
           default:
             throw new IllegalArgumentException(
                 "ON DELETE referential action not supported: " + action);
@@ -131,6 +133,7 @@ private void prettyPrint(Appendable appendable) throws IOException {
       switch (action.get()) {
         case ON_DELETE_CASCADE:
         case ON_DELETE_NO_ACTION:
+        case ON_DELETE_SET_NULL:
           appendable.append(" " + action.get().getSqlString());
           break;
         default:

v1/src/test/java/com/google/cloud/teleport/spanner/AvroSchemaToDdlConverterTest.java

@@ -248,9 +248,12 @@ public void simple() {
             + "  \"ALTER TABLE `Users` ADD CONSTRAINT `fk_odc` FOREIGN KEY (`last_name`) "
             + "  REFERENCES `AllowedNames` (`last_name`) ON DELETE CASCADE\","
             + "  \"spannerForeignKey_2\" : "
+            + "  \"ALTER TABLE `Users` ADD CONSTRAINT `fk_odsn` FOREIGN KEY (`last_name`) "
+            + "  REFERENCES `AllowedNames` (`last_name`) ON DELETE SET NULL\","
+            + "  \"spannerForeignKey_3\" : "
             + "  \"ALTER TABLE `Users` ADD CONSTRAINT `fk_not_enforced_no_action` FOREIGN KEY (`last_name`) "
             + "  REFERENCES `AllowedNames` (`last_name`) ON DELETE NO ACTION NOT ENFORCED\","
-            + "  \"spannerForeignKey_3\" : "
+            + "  \"spannerForeignKey_4\" : "
             + "  \"ALTER TABLE `Users` ADD CONSTRAINT `fk_enforced` FOREIGN KEY (`last_name`) "
             + "  REFERENCES `AllowedNames` (`last_name`) ENFORCED\","
             + "  \"spannerCheckConstraint_0\" : "
@@ -318,6 +321,9 @@ public void simple() {
                 + " ALTER TABLE `Users` ADD CONSTRAINT `fk_odc`"
                 + " FOREIGN KEY (`last_name`) REFERENCES "
                 + "`AllowedNames` (`last_name`) ON DELETE CASCADE"
+                + " ALTER TABLE `Users` ADD CONSTRAINT `fk_odsn`"
+                + " FOREIGN KEY (`last_name`) REFERENCES "
+                + "`AllowedNames` (`last_name`) ON DELETE SET NULL"
                 + " ALTER TABLE `Users` ADD CONSTRAINT `fk_not_enforced_no_action`"
                 + " FOREIGN KEY (`last_name`) REFERENCES "
                 + "`AllowedNames` (`last_name`) ON DELETE NO ACTION NOT ENFORCED"
@@ -544,6 +550,9 @@ public void pgSimple() {
             + " \"spannerForeignKey_1\" :   \"ALTER TABLE \\\"Users\\\" ADD CONSTRAINT "
             + "\\\"fk_odc\\\" FOREIGN KEY (\\\"last_name\\\")   REFERENCES \\\"AllowedNames\\\""
             + " (\\\"last_name\\\") ON DELETE CASCADE\", "
+            + " \"spannerForeignKey_2\" :   \"ALTER TABLE \\\"Users\\\" ADD CONSTRAINT "
+            + "\\\"fk_odsn\\\" FOREIGN KEY (\\\"last_name\\\")   REFERENCES \\\"AllowedNames\\\""
+            + " (\\\"last_name\\\") ON DELETE SET NULL\", "
             + " \"spannerCheckConstraint_0\" :   \"CONSTRAINT \\\"ck\\\""
             + " CHECK(\\\"first_name\\\" != \\\"last_name\\\")\"}";
 
@@ -606,7 +615,9 @@ public void pgSimple() {
                 + " ALTER TABLE \"Users\" ADD CONSTRAINT \"fk\" FOREIGN KEY (\"first_name\")"
                 + " REFERENCES \"AllowedNames\" (\"first_name\")"
                 + " ALTER TABLE \"Users\" ADD CONSTRAINT \"fk_odc\" FOREIGN KEY (\"last_name\")"
-                + " REFERENCES \"AllowedNames\" (\"last_name\") ON DELETE CASCADE"));
+                + " REFERENCES \"AllowedNames\" (\"last_name\") ON DELETE CASCADE"
+                + " ALTER TABLE \"Users\" ADD CONSTRAINT \"fk_odsn\" FOREIGN KEY (\"last_name\")"
+                + " REFERENCES \"AllowedNames\" (\"last_name\") ON DELETE SET NULL"));
   }
 
   @Test

v1/src/test/java/com/google/cloud/teleport/spanner/CopyDbIT.java

@@ -299,6 +299,8 @@ private void createAndPopulate(String sqlFile, Dialect dialect, int numBatches)
     }
   }
 
+  // TODO(b/550212069): Add integration test for Foreign Key ON DELETE SET NULL action after
+  // the feature release.
   @Test
   public void testAllSchemaAndDataGsql() throws Exception {
     createAndPopulate(

v1/src/test/java/com/google/cloud/teleport/spanner/DdlToAvroSchemaConverterTest.java

@@ -209,6 +209,8 @@ public void simple() {
                         + " REFERENCES `AllowedNames` (`first_name`)",
                     "ALTER TABLE `Users` ADD CONSTRAINT `fk_odc` FOREIGN KEY (`last_name`)"
                         + " REFERENCES `AllowedNames` (`last_name`) ON DELETE CASCADE",
+                    "ALTER TABLE `Users` ADD CONSTRAINT `fk_odsn` FOREIGN KEY (`last_name`)"
+                        + " REFERENCES `AllowedNames` (`last_name`) ON DELETE SET NULL",
                     "ALTER TABLE `Users` ADD CONSTRAINT `fk_not_enforced_no_action`"
                         + " FOREIGN KEY (`last_name`) REFERENCES "
                         + "`AllowedNames` (`last_name`) ON DELETE NO ACTION NOT ENFORCED",
@@ -395,11 +397,16 @@ public void simple() {
                 + " REFERENCES `AllowedNames` (`last_name`) ON DELETE CASCADE"));
     assertThat(
         avroSchema.getProp(SPANNER_FOREIGN_KEY + "2"),
+        equalTo(
+            "ALTER TABLE `Users` ADD CONSTRAINT `fk_odsn` FOREIGN KEY (`last_name`)"
+                + " REFERENCES `AllowedNames` (`last_name`) ON DELETE SET NULL"));
+    assertThat(
+        avroSchema.getProp(SPANNER_FOREIGN_KEY + "3"),
         equalTo(
             "ALTER TABLE `Users` ADD CONSTRAINT `fk_not_enforced_no_action` FOREIGN KEY (`last_name`)"
                 + " REFERENCES `AllowedNames` (`last_name`) ON DELETE NO ACTION NOT ENFORCED"));
     assertThat(
-        avroSchema.getProp(SPANNER_FOREIGN_KEY + "3"),
+        avroSchema.getProp(SPANNER_FOREIGN_KEY + "4"),
         equalTo(
             "ALTER TABLE `Users` ADD CONSTRAINT `fk_enforced` FOREIGN KEY (`last_name`)"
                 + " REFERENCES `AllowedNames` (`last_name`) ENFORCED"));

v1/src/test/java/com/google/cloud/teleport/spanner/ddl/DdlTest.java

@@ -1764,21 +1764,32 @@ public void testForeignKeyBuilderActions() {
     ForeignKey fkWithDeleteNoAction = fkWithDeleteNoActionBuilder.build();
     assertTrue(fkWithDeleteNoAction.equals(fkWithDeleteNoAction));
     assertFalse(fkWithDeleteCascade1.equals(fkWithDeleteNoAction));
+
+    ForeignKey.Builder fkWithDeleteSetNullBuilder =
+        ForeignKey.builder().name("fk_odsn").table("Users").referencedTable("AllowedNames");
+    fkWithDeleteSetNullBuilder.columnsBuilder().add("first_name", "last_name");
+    fkWithDeleteSetNullBuilder.referencedColumnsBuilder().add("first_name", "last_name");
+    fkWithDeleteSetNullBuilder.referentialAction(
+        Optional.of(ReferentialAction.ON_DELETE_SET_NULL));
+    ForeignKey fkWithDeleteSetNull = fkWithDeleteSetNullBuilder.build();
+    assertTrue(fkWithDeleteSetNull.equals(fkWithDeleteSetNull));
+    assertFalse(fkWithDeleteCascade1.equals(fkWithDeleteSetNull));
+    assertFalse(fkWithDeleteNoAction.equals(fkWithDeleteSetNull));
   }
 
   @Test
   public void testUnsupportedForeignKeyBuilderActionThrowsError() {
     ForeignKey.Builder fkWithUnsupportedActionBuilder =
-        ForeignKey.builder().name("fk_odsn").table("Users").referencedTable("AllowedNames");
+        ForeignKey.builder().name("fk_odr").table("Users").referencedTable("AllowedNames");
     fkWithUnsupportedActionBuilder.columnsBuilder().add("first_name", "last_name");
     fkWithUnsupportedActionBuilder.referencedColumnsBuilder().add("first_name", "last_name");
     fkWithUnsupportedActionBuilder.referentialAction(
-        Optional.of(ReferentialAction.ON_DELETE_SET_NULL));
+        Optional.of(ReferentialAction.ON_DELETE_RESTRICT));
     ForeignKey fkWithUnsupportedAction = fkWithUnsupportedActionBuilder.build();
     Throwable exception =
         assertThrows(IllegalArgumentException.class, () -> fkWithUnsupportedAction.prettyPrint());
     assertThat(exception.getMessage())
-        .matches("Foreign Key action not supported: ON DELETE SET NULL");
+        .matches("Foreign Key action not supported: ON DELETE RESTRICT");
   }
 
   @Test

v1/src/test/java/com/google/cloud/teleport/spanner/ddl/ForeignKeyTest.java

@@ -28,13 +28,16 @@
 public final class ForeignKeyTest {
 
   @Test
-  public void testParsingOnDeleteCascadeActions() {
+  public void testParsingOnDeleteActions() {
     var onDeleteCascadeAction = ReferentialAction.getReferentialAction("DELETE", "CASCADE");
     assertThat(onDeleteCascadeAction)
         .isEquivalentAccordingToCompareTo(ReferentialAction.ON_DELETE_CASCADE);
     var onDeleteNoAction = ReferentialAction.getReferentialAction("DELETE", "no action");
     assertThat(onDeleteNoAction)
         .isEquivalentAccordingToCompareTo(ReferentialAction.ON_DELETE_NO_ACTION);
+    var onDeleteSetNullAction = ReferentialAction.getReferentialAction("DELETE", "set null");
+    assertThat(onDeleteSetNullAction)
+        .isEquivalentAccordingToCompareTo(ReferentialAction.ON_DELETE_SET_NULL);
   }
 
   @Test

v1/src/test/java/com/google/cloud/teleport/spanner/ddl/RandomDdlGenerator.java

@@ -571,7 +571,9 @@ private void generateTable(Ddl.Builder builder, Table parent, int level) {
         }
         if (rnd.nextBoolean()) {
           ReferentialAction action = generateRandomReferentialAction(rnd);
-          if (!isEnforced && action == ReferentialAction.ON_DELETE_CASCADE) {
+          if (!isEnforced
+              && (action == ReferentialAction.ON_DELETE_CASCADE
+                  || action == ReferentialAction.ON_DELETE_SET_NULL)) {
             action = ReferentialAction.ON_DELETE_NO_ACTION;
           }
           foreignKeyBuilder.referentialAction(Optional.of(action));
@@ -625,9 +627,15 @@ private void generateTable(Ddl.Builder builder, Table parent, int level) {
   }
 
   private ReferentialAction generateRandomReferentialAction(Random rnd) {
-    return rnd.nextBoolean()
-        ? ReferentialAction.ON_DELETE_CASCADE
-        : ReferentialAction.ON_DELETE_NO_ACTION;
+    int actionChoice = rnd.nextInt(3);
+    switch (actionChoice) {
+      case 0:
+        return ReferentialAction.ON_DELETE_CASCADE;
+      case 1:
+        return ReferentialAction.ON_DELETE_SET_NULL;
+      default:
+        return ReferentialAction.ON_DELETE_NO_ACTION;
+    }
   }
 
   private String addDefaultValueToColumn(Type type) {