feat: add support for non-parent interleaving

Includes fix from #217

Author: nielm

src/main/java/com/google/cloud/solutions/spannerddl/parser/ASTtable_interleave_clause.java

@@ -30,8 +30,9 @@ public ASTtable_interleave_clause(DdlParser p, int id) {
   }
 
   public String getParentTableName() {
-    return AstTreeUtils.tokensToString(
-        AstTreeUtils.getChildByType(children, ASTinterleave_in.class));
+    return (AstTreeUtils.getOptionalChildByType(children, ASTparent.class) == null ? "" : "PARENT ")
+        + AstTreeUtils.tokensToString(
+            AstTreeUtils.getChildByType(children, ASTinterleave_in.class));
   }
 
   public String getOnDelete() {
@@ -46,14 +47,6 @@ public String getOnDelete() {
 
   @Override
   public String toString() {
-    return Joiner.on(" ")
-        .skipNulls()
-        .join(
-            "INTERLEAVE IN",
-            AstTreeUtils.getOptionalChildByType(children, ASTparent.class) == null
-                ? null
-                : "PARENT",
-            getParentTableName(),
-            getOnDelete());
+    return Joiner.on(" ").skipNulls().join("INTERLEAVE IN", getParentTableName(), getOnDelete());
   }
 }

src/test/java/com/google/cloud/solutions/spannerddl/diff/DdlDiffTest.java

@@ -319,6 +319,15 @@ public void generateAlterTable_changeInterleaving() throws DdlDiffException {
         true,
         "Cannot change interleaved parent of table test1");
 
+    // add  parent constraint
+    getDiffCheckDdlDiffException(
+        "create table test1 (col1 int64, col2 int64) "
+            + "primary key (col1), interleave in testparent;",
+        "create table test1 (col1 int64, col2 int64) "
+            + "primary key (col1), interleave in parent testparent",
+        true,
+        "Cannot change interleaved parent of table test1");
+
     // change on delete
     assertThat(
             getDiff(

src/test/resources/ddlParserValidation.txt

@@ -196,4 +196,11 @@ CREATE TABLE test1 (
   value INT64
 ) PRIMARY KEY (keycol ASC), OPTIONS (key='value')
 
+== Test 20 create table, interleave in non-parent
+
+CREATE TABLE test1 (
+  keycol INT64,
+  value INT64
+) PRIMARY KEY (keycol ASC), INTERLEAVE IN other_table ON DELETE NO ACTION
+
 ==