From 55ab718da70aee2ff4c37a79584fa0aa9ecea76d Mon Sep 17 00:00:00 2001
From: Jun Yuan <jyuan@splicemachine.com>
Date: Tue, 20 Jul 2021 11:37:31 -0700
Subject: [PATCH] DB-12363: fix drop column and constraints

---
 .../ModifyColumnConstantOperation.java        | 12 ++++-----
 .../sql/execute/operations/DropColumnIT.java  | 26 +++++++++++++++++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/splice_machine/src/main/java/com/splicemachine/derby/impl/sql/execute/actions/ModifyColumnConstantOperation.java b/splice_machine/src/main/java/com/splicemachine/derby/impl/sql/execute/actions/ModifyColumnConstantOperation.java
index d35b6c6beac..f69e63cc9ea 100644
--- a/splice_machine/src/main/java/com/splicemachine/derby/impl/sql/execute/actions/ModifyColumnConstantOperation.java
+++ b/splice_machine/src/main/java/com/splicemachine/derby/impl/sql/execute/actions/ModifyColumnConstantOperation.java
@@ -768,7 +768,7 @@ private void dropColumnFromTable(Activation activation,
         int maxStoragePosition = tableDescriptor.getColumnDescriptorList().maxStoragePosition();
         int size = tableDescriptor.getColumnDescriptorList().size();
         int droppedColumnPosition = columnDescriptor.getPosition();
-
+        int droppedStoragePosition = columnDescriptor.getStoragePosition();
         FormatableBitSet toDrop = new FormatableBitSet(maxStoragePosition + 1);
         toDrop.set(droppedColumnPosition);
         tableDescriptor.setReferencedColumnMap(toDrop);
@@ -786,7 +786,7 @@ private void dropColumnFromTable(Activation activation,
 
         // Now handle constraints
         List<ConstantAction> newCongloms = handleConstraints(activation, tableDescriptor, columnName, lcc, dd, dm, cascade, tc,
-                                                             droppedColumnPosition);
+                                                             droppedStoragePosition);
 
         /* If there are new backing conglomerates which must be
          * created to replace a dropped shared conglomerate
@@ -945,7 +945,7 @@ private List<ConstantAction> handleConstraints(Activation activation,
                                                    DependencyManager dm,
                                                    boolean cascade,
                                                    TransactionController tc,
-                                                   int droppedColumnPosition) throws StandardException {
+                                                   int droppedStoragePosition) throws StandardException {
         ConstraintDescriptorList csdl = dd.getConstraintDescriptors(td);
         int csdl_size = csdl.size();
 
@@ -964,16 +964,16 @@ private List<ConstantAction> handleConstraints(Activation activation,
             int numRefCols = referencedColumns.length, j;
             boolean changed = false;
             for (j = 0; j < numRefCols; j++) {
-                if (referencedColumns[j] > droppedColumnPosition)
+                if (referencedColumns[j] > droppedStoragePosition)
                     changed = true;
-                if (referencedColumns[j] == droppedColumnPosition)
+                if (referencedColumns[j] == droppedStoragePosition)
                     break;
             }
             if (j == numRefCols) {// column not referenced
                 if ((cd instanceof CheckConstraintDescriptor) && changed) {
                     dd.dropConstraintDescriptor(cd, tc);
                     for (j = 0; j < numRefCols; j++) {
-                        if (referencedColumns[j] > droppedColumnPosition)
+                        if (referencedColumns[j] > droppedStoragePosition)
                             referencedColumns[j]--;
                     }
                     ((CheckConstraintDescriptor) cd).setReferencedColumnsDescriptor(new ReferencedColumnsDescriptorImpl(referencedColumns));
diff --git a/splice_machine/src/test/java/com/splicemachine/derby/impl/sql/execute/operations/DropColumnIT.java b/splice_machine/src/test/java/com/splicemachine/derby/impl/sql/execute/operations/DropColumnIT.java
index 8dacde23228..2802d52d631 100644
--- a/splice_machine/src/test/java/com/splicemachine/derby/impl/sql/execute/operations/DropColumnIT.java
+++ b/splice_machine/src/test/java/com/splicemachine/derby/impl/sql/execute/operations/DropColumnIT.java
@@ -386,4 +386,30 @@ public void testCascadeDropTrigger() throws Exception {
             assertEquals(0, count);
         }
     }
+
+    @Test
+    public void testCascadeDropConstraint() throws Exception {
+        methodWatcher.execute("create table t6(c1 int)");
+        methodWatcher.execute("alter table t6 add c2 float");
+        methodWatcher.execute("alter table t6 drop c2");
+        methodWatcher.execute("alter table t6 add c3 float not null default 1 constraint con3 primary key");
+
+        try(Connection conn = methodWatcher.getOrCreateConnection();
+            Statement s = conn.createStatement()) {
+            s.execute("alter table t6 drop c3");
+            SQLWarning warning = s.getWarnings();
+            Assert.assertTrue(warning!=null);
+            Assert.assertEquals("01500", warning.getSQLState());
+        }
+
+        String sql = String.format("select count(*) from sys.sysprimarykeys where conglomerateid=(" +
+                "select conglomerateid from sys.sysconglomerates c, sys.sysschemas s, sys.systables t " +
+                "where s.schemaid=t.schemaid and t.tableid=c.tableid and s.schemaname='%s' and t.tablename='T6')",
+                SCHEMA_NAME);
+        try(ResultSet rs = methodWatcher.executeQuery(sql)) {
+            rs.next();
+            int count = rs.getInt(1);
+            Assert.assertEquals(0, count);
+        }
+    }
 }