flyway#1649 flyway:clean fails on db2 when trying to drop versioning …

…on tables which is accessed by a MQT

Make an explicit drop of all MQTs if there are tables with versioning

flyway-core/src/main/java/org/flywaydb/core/internal/dbsupport/db2/DB2Schema.java

@@ -77,7 +77,15 @@ protected void doClean() throws SQLException {
 
         if (dbSupport.getDb2MajorVersion() >= 10) {
             // drop versioned table link -> not supported for DB2 9.x
-            for (String dropVersioningStatement : generateDropVersioningStatement()) {
+            List<String> dropVersioningStatements = generateDropVersioningStatement();
+            if (!dropVersioningStatements.isEmpty()) {
+                // Do a explicit drop of MQTs in order to be able to drop the Versioning
+                for (String dropTableStatement : generateDropStatements("S", "TABLE")) {
+                    jdbcTemplate.execute(dropTableStatement);
+                }
+            }
+
+            for (String dropVersioningStatement : dropVersioningStatements) {
                 jdbcTemplate.execute(dropVersioningStatement);
             }
         }

flyway-core/src/test/resources/migration/dbsupport/db2/sql/mqt/V1__Mqt.sql

@@ -17,6 +17,16 @@
 create table EMPLOYEE ( "ID" integer not null, "NAME" varchar(100) );
 alter table EMPLOYEE add primary KEY ("ID");
 
+-- Issue #
+ALTER TABLE EMPLOYEE ADD COLUMN SYS_START TIMESTAMP(12) NOT NULL GENERATED AS ROW BEGIN IMPLICITLY HIDDEN;
+ALTER TABLE EMPLOYEE ADD COLUMN SYS_END TIMESTAMP(12) NOT NULL GENERATED AS ROW END IMPLICITLY HIDDEN;
+ALTER TABLE EMPLOYEE ADD COLUMN TRANS_ID TIMESTAMP(12) GENERATED AS TRANSACTION START ID IMPLICITLY HIDDEN;
+ALTER TABLE EMPLOYEE ADD PERIOD SYSTEM_TIME (sys_start, sys_end);
+
+CREATE TABLE EMPLOYEE_HIST LIKE EMPLOYEE;
+
+ALTER TABLE EMPLOYEE ADD VERSIONING USE HISTORY TABLE EMPLOYEE_HIST;
+
 create table ADDRESS ( "ID" integer not null, "EMPL_ID" integer not null, "STREET" VARCHAR(250) );
 alter TABLE ADDRESS add PRIMARY KEY ("ID");
 alter table ADDRESS add CONSTRAINT "EMPL" FOREIGN KEY("ID") REFERENCES "EMPLOYEE" ("ID");