#369 - Rollback of base column attributes

src/main/java/com/avaje/ebean/dbmigration/ddlgeneration/platform/BaseTableDdl.java

@@ -603,6 +603,22 @@ public class BaseTableDdl implements TableDdl {
     String ddl = platformDdl.alterColumnBaseAttributes(alter);
     if (hasValue(ddl)) {
       writer.apply().append(ddl).endOfStatement();
+
+      // reverse and generate the rollback statement
+      String currentType = alter.getCurrentType();
+      String type = alter.getType();
+      Boolean currentNotnull = alter.isCurrentNotnull();
+      Boolean notnull = alter.isNotnull();
+
+      alter.setCurrentType(type);
+      alter.setType(currentType);
+      alter.setNotnull(currentNotnull);
+      alter.setCurrentNotnull(notnull);
+
+      // write the rollback
+      ddl = platformDdl.alterColumnBaseAttributes(alter);
+      writer.rollback().append(ddl).endOfStatement();
+
       if (isTrue(alter.isWithHistory()) && alter.getType() != null) {
         // mysql and sql server column type change allowing nulls in the history table column
         AlterColumn alterHistoryColumn = new AlterColumn();
@@ -610,7 +626,14 @@ public class BaseTableDdl implements TableDdl {
         alterHistoryColumn.setColumnName(alter.getColumnName());
         alterHistoryColumn.setType(alter.getType());
         String histColumnDdl = platformDdl.alterColumnBaseAttributes(alterHistoryColumn);
+
+        // write the apply to history table
         writer.apply().append(histColumnDdl).endOfStatement();
+
+        // write the rollback from history table
+        alterHistoryColumn.setType(currentType);
+        histColumnDdl = platformDdl.alterColumnBaseAttributes(alterHistoryColumn);
+        writer.rollback().append(histColumnDdl).endOfStatement();
       }
     }
   }
@@ -628,6 +651,8 @@ public class BaseTableDdl implements TableDdl {
     String ddl = platformDdl.alterColumnNotnull(alter.getTableName(), alter.getColumnName(), alter.isNotnull());
     if (hasValue(ddl)) {
       writer.apply().append(ddl).endOfStatement();
+      ddl = platformDdl.alterColumnNotnull(alter.getTableName(), alter.getColumnName(), alter.isCurrentNotnull());
+      writer.rollback().append(ddl).endOfStatement();
     }
   }
 
@@ -636,10 +661,14 @@ public class BaseTableDdl implements TableDdl {
     String ddl = platformDdl.alterColumnType(alter.getTableName(), alter.getColumnName(), alter.getType());
     if (hasValue(ddl)) {
       writer.apply().append(ddl).endOfStatement();
+      ddl = platformDdl.alterColumnType(alter.getTableName(), alter.getColumnName(), alter.getCurrentType());
+      writer.rollback().append(ddl).endOfStatement();
       if (isTrue(alter.isWithHistory())) {
         // apply same type change to matching column in the history table
         ddl = platformDdl.alterColumnType(historyTable(alter.getTableName()), alter.getColumnName(), alter.getType());
         writer.apply().append(ddl).endOfStatement();
+        ddl = platformDdl.alterColumnType(historyTable(alter.getTableName()), alter.getColumnName(), alter.getCurrentType());
+        writer.rollback().append(ddl).endOfStatement();
       }
     }
   }

src/main/java/com/avaje/ebean/dbmigration/ddlgeneration/platform/MySqlHistoryDdl.java

@@ -66,7 +66,6 @@ public class MySqlHistoryDdl extends DbTriggerBasedHistoryDdl {
     addBeforeUpdate(rollback, updateTriggerName(baseTableName), baseTableName, historyTableName, includedColumns);
     addBeforeDelete(rollback, deleteTriggerName(baseTableName), baseTableName, historyTableName, includedColumns);
     rollback.append("unlock tables").endOfStatement();
-
   }
 
   private void addBeforeUpdate(DdlBuffer apply, String triggerName, String baseTable, String historyTable, List<String> includedColumns) throws IOException {
@@ -77,7 +76,7 @@ public class MySqlHistoryDdl extends DbTriggerBasedHistoryDdl {
         .append(" for each row begin").newLine();
     appendInsertIntoHistory(apply, historyTable, includedColumns);
     apply
-        .append("    set NEW.").append(sysPeriod).append("_start = now(6)").endOfStatement().newLine()
+        .append("    set NEW.").append(sysPeriod).append("_start = now(6)").endOfStatement()
         .append("end$$").newLine();
   }
 

src/main/java/com/avaje/ebean/dbmigration/model/MColumn.java

@@ -230,19 +230,18 @@ public class MColumn {
     // set to null and check at the end
     this.alterColumn = null;
 
-    boolean changeType = false;
-    boolean changeNotnull = false;
+    boolean changeBaseAttribute = false;
 
     if (historyExclude != newColumn.historyExclude) {
       getAlterColumn(tableName, tableWithHistory).setHistoryExclude(newColumn.historyExclude);
     }
 
     if (different(type, newColumn.type)) {
-      changeType = true;
+      changeBaseAttribute = true;
       getAlterColumn(tableName, tableWithHistory).setType(newColumn.type);
     }
     if (notnull != newColumn.notnull) {
-      changeNotnull = true;
+      changeBaseAttribute = true;
       getAlterColumn(tableName, tableWithHistory).setNotnull(newColumn.notnull);
     }
     if (different(defaultValue, newColumn.defaultValue)) {
@@ -302,11 +301,9 @@ public class MColumn {
 
     if (alterColumn != null) {
       modelDiff.addAlterColumn(alterColumn);
-      // we need the current type, notnull together for some db's
-      if (!changeType) {
+      if (changeBaseAttribute) {
+        // support reverting these changes
         alterColumn.setCurrentType(type);
-      }
-      if (!changeNotnull) {
         alterColumn.setCurrentNotnull(notnull);
       }
     }