#374 - Update migration generation

src/main/java/com/avaje/ebean/config/ServerConfig.java

@@ -162,6 +162,12 @@ public class ServerConfig {
    */
   private String asOfSysPeriod = "sys_period";
 
+  /**
+   * Suffix appended to the base table to derive the view that contains the union
+   * of the base table and the history table in order to support asOf queries.
+   */
+  private String historyTableSuffix = "_history";
+
   /**
    * Use for transaction scoped batch mode.
    */
@@ -676,6 +682,20 @@ public class ServerConfig {
     this.asOfSysPeriod = asOfSysPeriod;
   }
 
+  /**
+   * Return the history table suffix (defaults to _history).
+   */
+  public String getHistoryTableSuffix() {
+    return historyTableSuffix;
+  }
+
+  /**
+   * Set the history table suffix.
+   */
+  public void setHistoryTableSuffix(String historyTableSuffix) {
+    this.historyTableSuffix = historyTableSuffix;
+  }
+
   /**
    * Return true if we are running in a JTA Transaction manager.
    */
@@ -1960,6 +1980,7 @@ public class ServerConfig {
     diffFlatMode = p.getBoolean("diffFlatMode", diffFlatMode);
     asOfViewSuffix = p.get("asOfViewSuffix", asOfViewSuffix);
     asOfSysPeriod = p.get("asOfSysPeriod", asOfSysPeriod);
+    historyTableSuffix = p.get("historyTableSuffix", historyTableSuffix);
     dataSourceJndiName = p.get("dataSourceJndiName", dataSourceJndiName);
     databaseSequenceBatchSize = p.getInt("databaseSequenceBatchSize", databaseSequenceBatchSize);
     databaseBooleanTrue = p.get("databaseBooleanTrue", databaseBooleanTrue);

src/main/java/com/avaje/ebean/dbmigration/ddlgeneration/BaseDdlHandler.java

@@ -1,14 +1,15 @@
 package com.avaje.ebean.dbmigration.ddlgeneration;
 
-import com.avaje.ebean.config.DbConstraintNaming;
-import com.avaje.ebean.config.NamingConvention;
+import com.avaje.ebean.config.ServerConfig;
 import com.avaje.ebean.dbmigration.ddlgeneration.platform.BaseTableDdl;
 import com.avaje.ebean.dbmigration.ddlgeneration.platform.PlatformDdl;
 import com.avaje.ebean.dbmigration.migration.AddColumn;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
 import com.avaje.ebean.dbmigration.migration.AlterColumn;
 import com.avaje.ebean.dbmigration.migration.ChangeSet;
 import com.avaje.ebean.dbmigration.migration.CreateTable;
 import com.avaje.ebean.dbmigration.migration.DropColumn;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 
 import java.io.IOException;
 import java.util.List;
@@ -20,8 +21,8 @@ public class BaseDdlHandler implements DdlHandler {
 
   protected final TableDdl tableDdl;
 
-  public BaseDdlHandler(NamingConvention namingConvention, DbConstraintNaming naming, PlatformDdl platformDdl) {
-    this.tableDdl = new BaseTableDdl(namingConvention, naming, platformDdl);
+  public BaseDdlHandler(ServerConfig serverConfig, PlatformDdl platformDdl) {
+    this.tableDdl = new BaseTableDdl(serverConfig, platformDdl);
   }
 
   @Override
@@ -29,7 +30,7 @@ public class BaseDdlHandler implements DdlHandler {
 
     List<Object> changeSetChildren = changeSet.getChangeSetChildren();
     for (Object change : changeSetChildren) {
-      if (change instanceof  CreateTable) {
+      if (change instanceof CreateTable) {
         generate(writer, (CreateTable) change);
       } else if (change instanceof AddColumn) {
         generate(writer, (AddColumn) change);
@@ -37,10 +38,19 @@ public class BaseDdlHandler implements DdlHandler {
         generate(writer, (DropColumn) change);
       } else if (change instanceof AlterColumn) {
         generate(writer, (AlterColumn) change);
+      } else if (change instanceof AddHistoryTable) {
+        generate(writer, (AddHistoryTable) change);
+      } else if (change instanceof DropHistoryTable) {
+        generate(writer, (DropHistoryTable) change);
       }
     }
   }
 
+  @Override
+  public void generateExtra(DdlWrite write) throws IOException {
+    tableDdl.generateExtra(write);
+  }
+
   @Override
   public void generate(DdlWrite writer, CreateTable createTable) throws IOException {
     tableDdl.generate(writer, createTable);
@@ -60,4 +70,14 @@ public class BaseDdlHandler implements DdlHandler {
   public void generate(DdlWrite writer, AlterColumn alterColumn) throws IOException {
     tableDdl.generate(writer, alterColumn);
   }
+
+  @Override
+  public void generate(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException {
+    tableDdl.generate(writer, addHistoryTable);
+  }
+
+  @Override
+  public void generate(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException {
+    tableDdl.generate(writer, dropHistoryTable);
+  }
 }

src/main/java/com/avaje/ebean/dbmigration/ddlgeneration/DdlHandler.java

@@ -1,10 +1,12 @@
 package com.avaje.ebean.dbmigration.ddlgeneration;
 
 import com.avaje.ebean.dbmigration.migration.AddColumn;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
 import com.avaje.ebean.dbmigration.migration.AlterColumn;
 import com.avaje.ebean.dbmigration.migration.ChangeSet;
 import com.avaje.ebean.dbmigration.migration.CreateTable;
 import com.avaje.ebean.dbmigration.migration.DropColumn;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 
 import java.io.IOException;
 
@@ -22,4 +24,9 @@ public interface DdlHandler {
 
   void generate(DdlWrite writer, AlterColumn alterColumn) throws IOException;
 
+  void generate(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException;
+
+  void generate(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException;
+
+  void generateExtra(DdlWrite write) throws IOException;
 }

src/main/java/com/avaje/ebean/dbmigration/ddlgeneration/TableDdl.java

@@ -1,9 +1,11 @@
 package com.avaje.ebean.dbmigration.ddlgeneration;
 
 import com.avaje.ebean.dbmigration.migration.AddColumn;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
 import com.avaje.ebean.dbmigration.migration.AlterColumn;
 import com.avaje.ebean.dbmigration.migration.CreateTable;
 import com.avaje.ebean.dbmigration.migration.DropColumn;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 import com.avaje.ebean.dbmigration.migration.DropTable;
 
 import java.io.IOException;
@@ -37,4 +39,19 @@ public interface TableDdl {
    * Write the drop column change.
    */
   void generate(DdlWrite writer, DropColumn dropColumn) throws IOException;
+
+  /**
+   * Write the AddHistoryTable change.
+   */
+  void generate(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException;
+
+  /**
+   * Write the DropHistoryTable change.
+   */
+  void generate(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException;
+
+  /**
+   * Generate any extra DDL such as regeneration of history triggers.
+   */
+  void generateExtra(DdlWrite write) throws IOException;
 }

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

@@ -9,10 +9,12 @@ import com.avaje.ebean.dbmigration.ddlgeneration.DdlWrite;
 import com.avaje.ebean.dbmigration.ddlgeneration.TableDdl;
 import com.avaje.ebean.dbmigration.ddlgeneration.platform.util.IndexSet;
 import com.avaje.ebean.dbmigration.migration.AddColumn;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
 import com.avaje.ebean.dbmigration.migration.AlterColumn;
 import com.avaje.ebean.dbmigration.migration.Column;
 import com.avaje.ebean.dbmigration.migration.CreateTable;
 import com.avaje.ebean.dbmigration.migration.DropColumn;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 import com.avaje.ebean.dbmigration.migration.DropTable;
 import com.avaje.ebean.dbmigration.migration.ForeignKey;
 import com.avaje.ebean.dbmigration.model.MTable;
@@ -20,7 +22,9 @@ import com.avaje.ebean.dbmigration.model.MTable;
 import java.io.IOException;
 import java.math.BigInteger;
 import java.util.ArrayList;
+import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Set;
 
 /**
  * Base implementation for 'create table' and 'alter table' statements.
@@ -33,6 +37,8 @@ public class BaseTableDdl implements TableDdl {
 
   protected final PlatformDdl platformDdl;
 
+  private final String historyTableSuffix;
+
   /**
    * Used to check that indexes on foreign keys should be skipped as a unique index on the columns
    * already exists.
@@ -51,17 +57,20 @@ public class BaseTableDdl implements TableDdl {
   protected int countForeignKey;
   protected int countIndex;
 
-  public BaseTableDdl(ServerConfig serverConfig, PlatformDdl platformDdl) {
-    this(serverConfig.getNamingConvention(), serverConfig.getConstraintNaming(), platformDdl);
-  }
+  /**
+   * Base tables that have associated history tables that need their triggers
+   * regenerated as columns have been added or removed.
+   */
+  protected Set<String> regenerateHistoryTriggers = new LinkedHashSet<String>();
 
   /**
    * Construct with a naming convention and platform specific DDL.
    */
-  public BaseTableDdl(NamingConvention namingConvention, DbConstraintNaming naming, PlatformDdl platformDdl) {
-    this.namingConvention = namingConvention;
-    this.naming = naming;
+  public BaseTableDdl(ServerConfig serverConfig, PlatformDdl platformDdl) {
+    this.namingConvention = serverConfig.getNamingConvention();
+    this.naming = serverConfig.getConstraintNaming();
     this.platformDdl = platformDdl;
+    this.historyTableSuffix = serverConfig.getHistoryTableSuffix();
   }
 
   /**
@@ -449,26 +458,52 @@ public class BaseTableDdl implements TableDdl {
     return pk;
   }
 
+  @Override
+  public void generate(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException {
+    platformDdl.addHistoryTable(writer, addHistoryTable);
+  }
+
+  @Override
+  public void generate(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException {
+    platformDdl.dropHistoryTable(writer, dropHistoryTable);
+  }
+
+  @Override
+  public void generateExtra(DdlWrite write) throws IOException {
+    for (String baseTable : this.regenerateHistoryTriggers) {
+      platformDdl.regenerateHistoryTriggers(write, baseTable);
+    }
+  }
+
   @Override
   public void generate(DdlWrite writer, AddColumn addColumn) throws IOException {
 
     String tableName = addColumn.getTableName();
     List<Column> columns = addColumn.getColumn();
     for (Column column : columns) {
-      // apply
-      alterTableAddColumn(writer.apply(), tableName, column);
-
-      // rollback
+      alterTableAddColumn(writer.apply(), tableName, column, false);
       alterTableDropColumn(writer.rollback(), tableName, column.getName());
     }
+
+    if (isTrue(addColumn.isWithHistory())) {
+      // make same changes to the history table
+      String historyTable = historyTable(tableName);
+      regenerateHistoryTriggers(tableName);
+      for (Column column : columns) {
+        alterTableAddColumn(writer.apply(), historyTable, column, true);
+        alterTableDropColumn(writer.rollback(), historyTable, column.getName());
+      }
+    }
+
+    // add a bit of whitespace
+    writer.apply().end();
+    writer.rollback().end();
   }
 
   @Override
   public void generate(DdlWrite writer, DropTable dropTable) throws IOException {
 
-    String tableName = dropTable.getName();
-
-    dropTable(writer.drop(), tableName);
+    dropTable(writer.drop(), dropTable.getName());
   }
 
   @Override
@@ -477,16 +512,23 @@ public class BaseTableDdl implements TableDdl {
     String tableName = dropColumn.getTableName();
 
     alterTableDropColumn(writer.drop(), tableName, dropColumn.getColumnName());
+    if (isTrue(dropColumn.isWithHistory())) {
+      // also drop from the history table
+      regenerateHistoryTriggers(tableName);
+      alterTableDropColumn(writer.drop(), historyTable(tableName), dropColumn.getColumnName());
+    }
+
+    writer.drop().end();
   }
 
   @Override
   public void generate(DdlWrite writer, AlterColumn alterColumn) throws IOException {
 
-    if (isTrue(alterColumn.isHistoryExclude())) {
-      historyExcludeColumn(writer, alterColumn);
-    } else if (isFalse(alterColumn.isHistoryExclude())) {
-      historyIncludeColumn(writer, alterColumn);
-    }
+//    if (isTrue(alterColumn.isHistoryExclude())) {
+//      historyExcludeColumn(writer, alterColumn);
+//    } else if (isFalse(alterColumn.isHistoryExclude())) {
+//      historyIncludeColumn(writer, alterColumn);
+//    }
 
     if (hasValue(alterColumn.getDropForeignKey())) {
       alterColumnDropForeignKey(writer, alterColumn);
@@ -524,6 +566,17 @@ public class BaseTableDdl implements TableDdl {
     }
   }
 
+  protected String historyTable(String baseTable) {
+    return baseTable + historyTableSuffix;
+  }
+
+  /**
+   * Register the base table that we need to regenerate the history triggers on.
+   */
+  protected void regenerateHistoryTriggers(String baseTableName) {
+    regenerateHistoryTriggers.add(baseTableName);
+  }
+
   /**
    * This is mysql specific - alter all the base attributes of the column together.
    */
@@ -532,16 +585,21 @@ public class BaseTableDdl implements TableDdl {
     String ddl = platformDdl.alterColumnBaseAttributes(alter);
     if (hasValue(ddl)) {
       writer.apply().append(ddl).endOfStatement();
+      if (isTrue(alter.isWithHistory()) && alter.getType() != null) {
+        // mysql and sqlserver column type change allowing nulls in the history table column
+        AlterColumn alterHistoryColumn = new AlterColumn();
+        alterHistoryColumn.setTableName(historyTable(alter.getTableName()));
+        alterHistoryColumn.setColumnName(alter.getColumnName());
+        alterHistoryColumn.setType(alter.getType());
+        String histColumnDdl = platformDdl.alterColumnBaseAttributes(alterHistoryColumn);
+        writer.apply().append(histColumnDdl).endOfStatement();
+      }
     }
   }
 
   protected void alterColumnDefaultValue(DdlWrite writer, AlterColumn alter) throws IOException {
 
-    String tableName = alter.getTableName();
-    String columnName = alter.getColumnName();
-    String defaultValue = alter.getDefaultValue();
-
-    String ddl = platformDdl.alterColumnDefaultValue(tableName, columnName, defaultValue);
+    String ddl = platformDdl.alterColumnDefaultValue(alter.getTableName(), alter.getColumnName(), alter.getDefaultValue());
     if (hasValue(ddl)) {
       writer.apply().append(ddl).endOfStatement();
     }
@@ -549,11 +607,7 @@ public class BaseTableDdl implements TableDdl {
 
   protected void alterColumnNotnull(DdlWrite writer, AlterColumn alter) throws IOException {
 
-    String tableName = alter.getTableName();
-    String columnName = alter.getColumnName();
-    Boolean notnull = alter.isNotnull();
-
-    String ddl = platformDdl.alterColumnNotnull(tableName, columnName, notnull);
+    String ddl = platformDdl.alterColumnNotnull(alter.getTableName(), alter.getColumnName(), alter.isNotnull());
     if (hasValue(ddl)) {
       writer.apply().append(ddl).endOfStatement();
     }
@@ -561,16 +615,18 @@ public class BaseTableDdl implements TableDdl {
 
   protected void alterColumnType(DdlWrite writer, AlterColumn alter) throws IOException {
 
-    String tableName = alter.getTableName();
-    String columnName = alter.getColumnName();
-    String type = alter.getType();
-
-    String ddl = platformDdl.alterColumnType(tableName, columnName, type);
+    String ddl = platformDdl.alterColumnType(alter.getTableName(), alter.getColumnName(), alter.getType());
     if (hasValue(ddl)) {
       writer.apply().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();
+      }
     }
   }
 
+
   protected void alterColumnAddForeignKey(DdlWrite writer, AlterColumn alterColumn) throws IOException {
 
     String tableName = alterColumn.getTableName();
@@ -590,21 +646,16 @@ public class BaseTableDdl implements TableDdl {
 
   protected void alterColumnDropForeignKey(DdlWrite writer, AlterColumn alter) throws IOException {
 
-    String tableName = alter.getTableName();
-    String fkName = alter.getDropForeignKey();
     writer.apply()
-        .append(platformDdl.alterTableDropForeignKey(tableName, fkName))
+        .append(platformDdl.alterTableDropForeignKey(alter.getTableName(), alter.getDropForeignKey()))
         .endOfStatement();
   }
 
 
   protected void alterColumnDropUniqueConstraint(DdlWrite writer, AlterColumn alter) throws IOException {
 
-    String tableName = alter.getTableName();
-    String uqName = alter.getDropUnique();
-
     writer.apply()
-        .append(platformDdl.dropIndex(uqName, tableName))
+        .append(platformDdl.dropIndex(alter.getDropUnique(), alter.getTableName()))
         .endOfStatement();
   }
 
@@ -620,16 +671,14 @@ public class BaseTableDdl implements TableDdl {
 
   protected void addUniqueConstraint(DdlWrite writer, AlterColumn alter, String uqName) throws IOException {
 
-    String tableName = alter.getTableName();
-    String columnName = alter.getColumnName();
+    String[] cols = {alter.getColumnName()};
 
-    String[] cols = {columnName};
     writer.apply()
-        .append(platformDdl.createExternalUniqueForOneToOne(uqName, tableName, cols))
+        .append(platformDdl.createExternalUniqueForOneToOne(uqName, alter.getTableName(), cols))
         .endOfStatement();
 
     writer.rollbackForeignKeys()
-        .append(platformDdl.dropIndex(uqName, tableName))
+        .append(platformDdl.dropIndex(uqName, alter.getTableName()))
         .endOfStatement();
   }
 
@@ -638,30 +687,24 @@ public class BaseTableDdl implements TableDdl {
 
     buffer.append("alter table ").append(tableName)
         .append(" drop column ").append(columnName)
-        .endOfStatement().end();
+        .endOfStatement();
   }
 
-  protected void alterTableAddColumn(DdlBuffer buffer, String tableName, Column column) throws IOException {
+  protected void alterTableAddColumn(DdlBuffer buffer, String tableName, Column column, boolean onHistoryTable) throws IOException {
 
     buffer.append("alter table ").append(tableName)
         .append(" add column ").append(column.getName())
         .append(" ").append(column.getType());
 
-    if (isTrue(column.isNotnull())) {
-      buffer.append(" not null");
+    if (!onHistoryTable) {
+      if (isTrue(column.isNotnull())) {
+        buffer.append(" not null");
+      }
+      if (hasValue(column.getCheckConstraint())) {
+        buffer.append(" ").append(column.getCheckConstraint());
+      }
     }
-    if (hasValue(column.getCheckConstraint())) {
-      buffer.append(" ").append(column.getCheckConstraint());
-    }
-    buffer.endOfStatement().end();
-  }
-
-  protected void historyIncludeColumn(DdlWrite writer, AlterColumn alterColumn) {
-    platformDdl.historyIncludeColumn(writer, alterColumn);
-  }
-
-  protected void historyExcludeColumn(DdlWrite writer, AlterColumn alterColumn) {
-    platformDdl.historyExcludeColumn(writer, alterColumn);
+    buffer.endOfStatement();
   }
 
   protected boolean isFalse(Boolean value) {

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

@@ -2,6 +2,8 @@ package com.avaje.ebean.dbmigration.ddlgeneration.platform;
 
 import com.avaje.ebean.config.ServerConfig;
 import com.avaje.ebean.dbmigration.ddlgeneration.DdlWrite;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 import com.avaje.ebean.dbmigration.model.MTable;
 
 import java.io.IOException;
@@ -21,4 +23,19 @@ public class NoHistorySupportDdl implements PlatformHistoryDdl {
   public void createWithHistory(DdlWrite writer, MTable table) throws IOException {
     // does nothing
   }
+
+  @Override
+  public void dropHistoryTable(DdlWrite writer, DropHistoryTable dropHistoryTable) {
+    // does nothing
+  }
+
+  @Override
+  public void addHistoryTable(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException {
+    // does nothing
+  }
+
+  @Override
+  public void regenerateHistoryTriggers(DdlWrite write, String baseTable) {
+    // does nothing
+  }
 }

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

@@ -8,7 +8,9 @@ import com.avaje.ebean.dbmigration.ddlgeneration.BaseDdlHandler;
 import com.avaje.ebean.dbmigration.ddlgeneration.DdlHandler;
 import com.avaje.ebean.dbmigration.ddlgeneration.DdlWrite;
 import com.avaje.ebean.dbmigration.ddlgeneration.platform.util.PlatformTypeConverter;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
 import com.avaje.ebean.dbmigration.migration.AlterColumn;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 import com.avaje.ebean.dbmigration.migration.IdentityType;
 import com.avaje.ebean.dbmigration.model.MTable;
 
@@ -76,7 +78,7 @@ public class PlatformDdl {
 
   public DdlHandler createDdlHandler(ServerConfig serverConfig) {
     historyDdl.configure(serverConfig);
-    return new BaseDdlHandler(serverConfig.getNamingConvention(), serverConfig.getConstraintNaming(), this);
+    return new BaseDdlHandler(serverConfig, this);
   }
 
   public IdType useIdentityType(IdentityType modelIdentityType) {
@@ -120,6 +122,18 @@ public class PlatformDdl {
     historyDdl.createWithHistory(writer, table);
   }
 
+  public void dropHistoryTable(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException {
+    historyDdl.dropHistoryTable(writer, dropHistoryTable);
+  }
+
+  public void addHistoryTable(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException {
+    historyDdl.addHistoryTable(writer, addHistoryTable);
+  }
+
+  public void regenerateHistoryTriggers(DdlWrite write, String baseTable) throws IOException {
+    historyDdl.regenerateHistoryTriggers(write, baseTable);
+  }
+
   /**
    * Generate and return the create sequence DDL.
    */
@@ -176,15 +190,6 @@ public class PlatformDdl {
     return "";
   }
 
-  public void historyExcludeColumn(DdlWrite writer, AlterColumn alterColumn) {
-
-  }
-
-  public void historyIncludeColumn(DdlWrite writer, AlterColumn alterColumn) {
-
-  }
-
-
   public String alterColumnType(String tableName, String columnName, String type) {
 
     return "alter table " + tableName + " " + alterColumn + " " + columnName + " " + columnSetType + type;

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

@@ -2,6 +2,8 @@ package com.avaje.ebean.dbmigration.ddlgeneration.platform;
 
 import com.avaje.ebean.config.ServerConfig;
 import com.avaje.ebean.dbmigration.ddlgeneration.DdlWrite;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 import com.avaje.ebean.dbmigration.model.MTable;
 
 import java.io.IOException;
@@ -13,7 +15,6 @@ public interface PlatformHistoryDdl {
 
   /**
    * Configure typically reading the
-   * @param serverConfig
    */
   void configure(ServerConfig serverConfig);
 
@@ -22,4 +23,9 @@ public interface PlatformHistoryDdl {
    */
   void createWithHistory(DdlWrite writer, MTable table) throws IOException;
 
+  void dropHistoryTable(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException;
+
+  void addHistoryTable(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException;
+
+  void regenerateHistoryTriggers(DdlWrite write, String baseTable) throws IOException;
 }

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

@@ -4,6 +4,8 @@ import com.avaje.ebean.config.DbConstraintNaming;
 import com.avaje.ebean.config.ServerConfig;
 import com.avaje.ebean.dbmigration.ddlgeneration.DdlBuffer;
 import com.avaje.ebean.dbmigration.ddlgeneration.DdlWrite;
+import com.avaje.ebean.dbmigration.migration.AddHistoryTable;
+import com.avaje.ebean.dbmigration.migration.DropHistoryTable;
 import com.avaje.ebean.dbmigration.model.MColumn;
 import com.avaje.ebean.dbmigration.model.MTable;
 
@@ -21,7 +23,7 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
 
   private String viewSuffix;
 
-  private String historySuffix = "_history";
+  private String historySuffix;
 
   public PostgresHistoryDdl() {
   }
@@ -30,20 +32,51 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
   public void configure(ServerConfig serverConfig) {
     this.sysPeriod = serverConfig.getAsOfSysPeriod();
     this.viewSuffix = serverConfig.getAsOfViewSuffix();
+    this.historySuffix = serverConfig.getHistoryTableSuffix();
     this.constraintNaming = serverConfig.getConstraintNaming();
   }
 
+  @Override
+  public void regenerateHistoryTriggers(DdlWrite writer, String baseTable) throws IOException {
+
+    MTable table = writer.getTable(baseTable);
+    if (table == null) {
+      throw new IllegalStateException("MTable "+baseTable+" not found in writer? (required for history DDL)");
+    }
+    addStoredFunction(writer, table);
+  }
+
+  @Override
+  public void dropHistoryTable(DdlWrite writer, DropHistoryTable dropHistoryTable) throws IOException {
+
+    String baseTable = dropHistoryTable.getBaseTable();
+
+    // drop in appropriate order
+    dropTriggersEtc(writer.dropHistory(), baseTable);
+    dropHistoryTableEtc(writer.dropHistory(), baseTable);
+  }
+
+
+  @Override
+  public void addHistoryTable(DdlWrite writer, AddHistoryTable addHistoryTable) throws IOException {
+
+    String baseTable = addHistoryTable.getBaseTable();
+    MTable table = writer.getTable(baseTable);
+    if (table == null) {
+      throw new IllegalStateException("MTable "+baseTable+" not found in writer? (required for history DDL)");
+    }
+
+    createWithHistory(writer, table);
+  }
+
   @Override
   public void createWithHistory(DdlWrite writer, MTable table) throws IOException {
 
-
     String baseTable = table.getName();
 
-    // rollback trigger then function
-    DdlBuffer rollback = writer.rollback();
-    rollback.append("drop trigger if exists ").append(triggerName(baseTable)).append(" on ").append(baseTable).append(" cascade").endOfStatement();
-    rollback.append("drop function if exists ").append(procedureName(baseTable)).append("()").endOfStatement();
-    rollback.end();
+    // rollback changes in appropriate order
+    dropTriggersEtc(writer.rollback(), baseTable);
+    dropHistoryTableEtc(writer.rollback(), baseTable);
 
     addHistoryTable(writer, table);
     addStoredFunction(writer, table);
@@ -66,7 +99,15 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
     return normalise(baseTableName) + "_history_upd";
   }
 
-  public void addHistoryTable(DdlWrite writer, MTable table) throws IOException {
+  protected void dropTriggersEtc(DdlBuffer buffer, String baseTable) throws IOException {
+
+    // rollback trigger then function
+    buffer.append("drop trigger if exists ").append(triggerName(baseTable)).append(" on ").append(baseTable).append(" cascade").endOfStatement();
+    buffer.append("drop function if exists ").append(procedureName(baseTable)).append("()").endOfStatement();
+    buffer.end();
+  }
+
+  protected void addHistoryTable(DdlWrite writer, MTable table) throws IOException {
 
     String baseTableName = table.getName();
 
@@ -87,15 +128,16 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
         .append(" as select * from ").append(baseTableName)
         .append(" union all select * from ").append(baseTableName).append(historySuffix)
         .endOfStatement().end();
-
-    // rollback changes in appropriate order
-    DdlBuffer rollback = writer.rollback();
-    rollback.append("drop view ").append(baseTableName).append(viewSuffix).endOfStatement();
-    rollback.append("alter table ").append(baseTableName).append(" drop column ").append(sysPeriod).endOfStatement();
-    rollback.append("drop table ").append(baseTableName).append(historySuffix).endOfStatement().end();
   }
 
-  public void addTrigger(DdlWrite writer, MTable table) throws IOException {
+  protected void dropHistoryTableEtc(DdlBuffer buffer, String baseTableName) throws IOException {
+
+    buffer.append("drop view ").append(baseTableName).append(viewSuffix).endOfStatement();
+    buffer.append("alter table ").append(baseTableName).append(" drop column ").append(sysPeriod).endOfStatement();
+    buffer.append("drop table ").append(baseTableName).append(historySuffix).endOfStatement().end();
+  }
+
+  protected void addTrigger(DdlWrite writer, MTable table) throws IOException {
 
     String baseTableName = table.getName();
     String procedureName = procedureName(baseTableName);
@@ -108,7 +150,7 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
         .append("  for each row execute procedure ").append(procedureName).append("();").newLine().newLine();
   }
 
-  public void addStoredFunction(DdlWrite writer, MTable table) throws IOException {
+  protected void addStoredFunction(DdlWrite writer, MTable table) throws IOException {
 
     String procedureName = procedureName(table.getName());
 
@@ -142,7 +184,7 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
 
   protected void appendInsertIntoHistory(DdlBuffer buffer, MTable table) throws IOException {
 
-    String historyTable  = historyTableName(table.getName());
+    String historyTable = historyTableName(table.getName());
 
     buffer.append("    insert into ").append(historyTable).append(" (").append(sysPeriod).append(",");
     appendColumnNames(buffer, table, "");
@@ -156,11 +198,13 @@ public class PostgresHistoryDdl implements PlatformHistoryDdl {
     Collection<MColumn> columns = table.getColumns().values();
     int i = 0;
     for (MColumn column : columns) {
-      if (++i > 1) {
-        buffer.append(", ");
+      if (!column.isHistoryExclude()) {
+        if (++i > 1) {
+          buffer.append(", ");
+        }
+        buffer.append(columnPrefix);
+        buffer.append(column.getName());
       }
-      buffer.append(columnPrefix);
-      buffer.append(column.getName());
     }
   }
 }

src/main/java/com/avaje/ebean/dbmigration/migration/DropColumn.java

@@ -19,6 +19,7 @@ import javax.xml.bind.annotation.XmlType;
  *     <restriction base="{http://www.w3.org/2001/XMLSchema}anyType">
  *       <attribute name="columnName" use="required" type="{http://www.w3.org/2001/XMLSchema}string" />
  *       <attribute name="tableName" use="required" type="{http://www.w3.org/2001/XMLSchema}string" />
+ *       <attribute name="withHistory" type="{http://www.w3.org/2001/XMLSchema}boolean" />
  *     </restriction>
  *   </complexContent>
  * </complexType>
@@ -35,6 +36,8 @@ public class DropColumn {
     protected String columnName;
     @XmlAttribute(name = "tableName", required = true)
     protected String tableName;
+    @XmlAttribute(name = "withHistory")
+    protected Boolean withHistory;
 
     /**
      * Gets the value of the columnName property.
@@ -84,4 +87,28 @@ public class DropColumn {
         this.tableName = value;
     }
 
+    /**
+     * Gets the value of the withHistory property.
+     * 
+     * @return
+     *     possible object is
+     *     {@link Boolean }
+     *     
+     */
+    public Boolean isWithHistory() {
+        return withHistory;
+    }
+
+    /**
+     * Sets the value of the withHistory property.
+     * 
+     * @param value
+     *     allowed object is
+     *     {@link Boolean }
+     *     
+     */
+    public void setWithHistory(Boolean value) {
+        this.withHistory = value;
+    }
+
 }

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

@@ -163,11 +163,6 @@ public class MTable {
     }
 
     if (addColumn != null) {
-      if (withHistory) {
-        // These addColumns need to occur on the history
-        // table as well as the base table
-        addColumn.setWithHistory(Boolean.TRUE);
-      }
       modelDiff.addAddColumn(addColumn);
     }
   }
@@ -379,6 +374,11 @@ public class MTable {
     if (addColumn == null) {
       addColumn = new AddColumn();
       addColumn.setTableName(name);
+      if (withHistory) {
+        // These addColumns need to occur on the history
+        // table as well as the base table
+        addColumn.setWithHistory(Boolean.TRUE);
+      }
     }
 
     addColumn.getColumn().add(newColumn.createColumn());
@@ -389,6 +389,11 @@ public class MTable {
     DropColumn dropColumn = new DropColumn();
     dropColumn.setTableName(name);
     dropColumn.setColumnName(existingColumn.getName());
+    if (withHistory) {
+      // These dropColumns should occur on the history
+      // table as well as the base table
+      dropColumn.setWithHistory(Boolean.TRUE);
+    }
 
     modelDiff.addDropColumn(dropColumn);
   }

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

@@ -49,6 +49,7 @@ public class ModelDdlWriter {
         handler.generate(write, changeSet);
       }
     }
+    handler.generateExtra(write);
 
     return changeSetCount > 0;
   }