Throw COLUMN_IS_REFERENCED_1 instead of VIEW_IS_INVALID_2 from DROP COLUMN

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Issue #1475: Dropping column used by a view produces misleading error message
+</li>
 <li>Issue #1473: TestScript needs better detection of sorted result
 </li>
 <li>PR #1471: issue 1350: TestCrashAPI: PageStore.freeListPagesPerList

h2/src/main/org/h2/command/ddl/AlterTableAlterColumn.java

@@ -297,7 +297,7 @@ public class AlterTableAlterColumn extends CommandWithColumns {
             checkViews(table, newTable);
         } catch (DbException e) {
             execute("DROP TABLE " + newTable.getName(), true);
-            throw DbException.get(ErrorCode.VIEW_IS_INVALID_2, e, getSQL(), e.getMessage());
+            throw e;
         }
         String tableName = table.getName();
         ArrayList<TableView> dependentViews = new ArrayList<>(table.getDependentViews());
@@ -547,7 +547,11 @@ public class AlterTableAlterColumn extends CommandWithColumns {
                 // check if the query is still valid
                 // do not execute, not even with limit 1, because that could
                 // have side effects or take a very long time
-                session.prepare(sql);
+                try {
+                    session.prepare(sql);
+                } catch (DbException e) {
+                    throw DbException.get(ErrorCode.COLUMN_IS_REFERENCED_1, e, view.getSQL());
+                }
                 checkViewsAreValid(view);
             }
         }

h2/src/test/org/h2/test/scripts/ddl/alterTableDropColumn.sql

@@ -78,3 +78,21 @@ SELECT * FROM TEST;
 
 DROP TABLE TEST;
 > ok
+
+CREATE TABLE T1(ID INT PRIMARY KEY, C INT);
+> ok
+
+CREATE VIEW V1 AS SELECT C FROM T1;
+> ok
+
+ALTER TABLE T1 DROP COLUMN C;
+> exception COLUMN_IS_REFERENCED_1
+
+DROP VIEW V1;
+> ok
+
+ALTER TABLE T1 DROP COLUMN C;
+> ok
+
+DROP TABLE T1;
+> ok