DB2: Migration generation with Reorg table support (#54)

* prototype for reorg table

* DB2 Migration fixes

* Reorg handled by BaseTableDdl

Co-authored-by: Roland Praml <roland.praml@foconis.de>

ebean-ddl-generator/pom.xml

@@ -76,6 +76,13 @@
       <scope>test</scope>
     </dependency>
 
+    <dependency>
+      <groupId>com.ibm.db2</groupId>
+      <artifactId>jcc</artifactId>
+      <version>11.5.6.0</version>
+      <scope>test</scope>
+    </dependency>
+
   </dependencies>
 
   <build>

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/BaseTableDdl.java

@@ -35,9 +35,11 @@ import io.ebeaninternal.server.deploy.IdentityMode;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import static io.ebean.util.StringHelper.replace;
 import static io.ebeaninternal.api.PlatformMatch.matchPlatform;
@@ -87,7 +89,11 @@ public class BaseTableDdl implements TableDdl {
    * columns have been added, removed, included or excluded.
    */
   protected final Map<String, HistoryTableUpdate> regenerateHistoryTriggers = new LinkedHashMap<>();
-
+  
+  private final Set<String> needsReorg = new HashSet<>();
+  
+  private int reorgCount;
+  
   private final boolean strictMode;
 
   private final HistorySupport historySupport;
@@ -144,25 +150,28 @@ public class BaseTableDdl implements TableDdl {
     void writeBefore(DdlBuffer buffer) throws IOException {
       if (!before.isEmpty()) {
         buffer.end();
+        flushReorgTables(buffer);
+        if (withHistory) {
+          buffer.append("-- NOTE: table has @History - special migration may be necessary").newLine();
+        }
+        for (String ddlScript : before) {
+          buffer.appendStatement(translate(ddlScript, tableName, columnName, defaultValue));
+        }
       }
 
-      if (!before.isEmpty() && withHistory) {
-        buffer.append("-- NOTE: table has @History - special migration may be necessary").newLine();
-      }
-      for (String ddlScript : before) {
-        buffer.appendStatement(translate(ddlScript, tableName, columnName, defaultValue));
-      }
     }
 
     void writeAfter(DdlBuffer buffer) throws IOException {
-      if (!after.isEmpty() && withHistory) {
-        buffer.append("-- NOTE: table has @History - special migration may be necessary").newLine();
-      }
-      // here we run post migration scripts
-      for (String ddlScript : after) {
-        buffer.appendStatement(translate(ddlScript, tableName, columnName, defaultValue));
-      }
       if (!after.isEmpty()) {
+        if (withHistory) {
+          buffer.append("-- NOTE: table has @History - special migration may be necessary").newLine();
+        }
+        flushReorgTables(buffer);
+        
+        // here we run post migration scripts
+        for (String ddlScript : after) {
+          buffer.appendStatement(translate(ddlScript, tableName, columnName, defaultValue));
+        }
         buffer.end();
       }
     }
@@ -577,6 +586,7 @@ public class BaseTableDdl implements TableDdl {
   @Override
   public void generate(DdlWrite writer, CreateIndex index) throws IOException {
     if (platformInclude(index.getPlatforms())) {
+      flushReorgTables(writer.apply());
       writer.apply().appendStatement(platformDdl.createIndex(new WriteCreateIndex(index)));
       writer.dropAll().appendStatement(platformDdl.dropIndex(index.getIndexName(), index.getTableName(), Boolean.TRUE.equals(index.isConcurrent())));
     }
@@ -585,6 +595,7 @@ public class BaseTableDdl implements TableDdl {
   @Override
   public void generate(DdlWrite writer, DropIndex dropIndex) throws IOException {
     if (platformInclude(dropIndex.getPlatforms())) {
+      flushReorgTables(writer.apply());
       writer.apply().appendStatement(platformDdl.dropIndex(dropIndex.getIndexName(), dropIndex.getTableName(), Boolean.TRUE.equals(dropIndex.isConcurrent())));
     }
   }
@@ -596,6 +607,7 @@ public class BaseTableDdl implements TableDdl {
         writer.apply().appendStatement(platformDdl.alterTableDropUniqueConstraint(constraint.getTableName(), constraint.getConstraintName()));
 
       } else {
+        flushReorgTables(writer.apply());
         String[] cols = split(constraint.getColumnNames());
         String[] nullableColumns = split(constraint.getNullableColumns());
         writer.apply().appendStatement(platformDdl.alterTableAddUniqueConstraint(constraint.getTableName(), constraint.getConstraintName(), cols, nullableColumns));
@@ -648,6 +660,7 @@ public class BaseTableDdl implements TableDdl {
       platformDdl.unlockTables(write.applyHistoryTrigger(), regenerateHistoryTriggers.keySet());
     }
     platformDdl.generateEpilog(write);
+    flushReorgTables(write.apply());
   }
 
   @Override
@@ -838,11 +851,13 @@ public class BaseTableDdl implements TableDdl {
 
   protected void alterColumnNotnull(DdlWrite writer, AlterColumn alter) throws IOException {
     writer.apply().appendStatement(platformDdl.alterColumnNotnull(alter.getTableName(), alter.getColumnName(), alter.isNotnull()));
+    needsReorg.add(alter.getTableName());
   }
 
   protected void alterColumnType(DdlWrite writer, AlterColumn alter) throws IOException {
     String ddl = platformDdl.alterColumnType(alter.getTableName(), alter.getColumnName(), alter.getType());
     if (hasValue(ddl)) {
+      needsReorg.add(alter.getTableName());
       writer.apply().appendStatement(ddl);
       if (isTrue(alter.isWithHistory()) && historySupport == HistorySupport.TRIGGER_BASED) {
         regenerateHistoryTriggers(alter.getTableName(), HistoryTableUpdate.Change.ALTER, alter.getColumnName());
@@ -884,6 +899,7 @@ public class BaseTableDdl implements TableDdl {
 
   protected void alterTableDropColumn(DdlBuffer buffer, String tableName, String columnName) throws IOException {
     platformDdl.alterTableDropColumn(buffer, tableName, columnName);
+    needsReorg.add(tableName);
   }
 
   protected void alterTableAddColumn(DdlBuffer buffer, String tableName, Column column, boolean onHistoryTable, boolean withHistory) throws IOException {
@@ -903,6 +919,13 @@ public class BaseTableDdl implements TableDdl {
     }
   }
 
+  protected void flushReorgTables(DdlBuffer buffer) throws IOException {
+    for (String table : needsReorg) {
+      buffer.appendStatement(platformDdl.reorgTable(table, ++reorgCount));
+    }
+    needsReorg.clear();
+  }
+
   protected boolean isFalse(Boolean value) {
     return value != null && !value;
   }

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/DB2Ddl.java

@@ -5,44 +5,137 @@ import io.ebean.config.dbplatform.DatabasePlatform;
 
 /**
  * DB2 platform specific DDL.
+ * 
+ * according to the list
+ * https://datageek.blog/en/2014/05/06/db2-basics-what-is-a-reorg/ a reorg is
+ * necessary after
+ * <ol>
+ * <li>Data type changes that increase the size of a varchar or vargraphic
+ * column
+ * <li>Data type changes that decrease the size of a varchar or vargraphic
+ * column
+ * <li>Altering a column to include NOT NULL
+ * <li>Altering a column to inline LOBS
+ * <li>Altering a column to compress the system default or turn off compression
+ * for the system default
+ * <li>Altering a table to enable value compression
+ * <li>Altering a table to drop a column
+ * <li>Changing the PCTFREE for a table
+ * <li>Altering a table to turn APEND mode off
+ * <li>Altering a table or index to turn compression on
+ * </ol>
+ * 
+ * This is currently handled by BaseTableDdl
+ * 
  */
 public class DB2Ddl extends PlatformDdl {
-
+  
   public DB2Ddl(DatabasePlatform platform) {
     super(platform);
     this.dropTableIfExists = "drop table ";
     this.dropSequenceIfExists = "drop sequence ";
-    this.dropConstraintIfExists = "drop constraint";
-    this.dropIndexIfExists = "drop index ";
+    this.dropConstraintIfExists = "NOT USED";
+    this.dropIndexIfExists = "NOT USED";
     this.identitySuffix = " generated by default as identity";
+    this.columnSetNull = "drop not null";
+    this.columnSetType = "set data type ";
     this.inlineUniqueWhenNullable = false;
   }
 
   @Override
-  public String alterTableAddUniqueConstraint(String tableName, String uqName, String[] columns, String[] nullableColumns) {
+  public String alterTableAddUniqueConstraint(String tableName, String uqName, String[] columns,
+      String[] nullableColumns) {
+    StringBuilder sb = new StringBuilder(300);
     if (nullableColumns == null || nullableColumns.length == 0) {
-      return super.alterTableAddUniqueConstraint(tableName, uqName, columns, nullableColumns);
-    }     
+      sb.append("alter table ").append(lowerTableName(tableName));
+      sb.append(" add constraint ").append(maxConstraintName(uqName)).append(" unique ");
+      appendColumns(columns, sb);
+      return sb.toString();
+    }
 
     if (uqName == null) {
       throw new NullPointerException();
     }
-    StringBuilder sb = new StringBuilder("create unique index ");
-    sb.append(uqName).append(" on ").append(tableName).append('(');
-
+    sb.append("create unique index ").append(maxConstraintName(uqName));
+    sb.append(" on ").append(lowerTableName(tableName)).append('(');
     for (int i = 0; i < columns.length; i++) {
       if (i > 0) {
         sb.append(",");
       }
-      sb.append(columns[i]);
+      sb.append(lowerColumnName(columns[i]));
     }
     sb.append(") exclude null keys");
     return sb.toString();
   }
 
+  @Override
+  public String alterTableDropUniqueConstraint(String tableName, String uniqueConstraintName) {
+    return alterTableDropConstraint(tableName, uniqueConstraintName) + "\n"
+        + dropIndex(uniqueConstraintName, tableName);
+  }
+
   @Override
   protected void appendForeignKeyOnUpdate(StringBuilder buffer, ConstraintMode mode) {
     // do nothing, no on update clause for db2
   }
 
+
+  @Override
+  public String dropSequence(String sequenceName) {
+    StringBuilder sb = new StringBuilder(300);
+    sb.append("delimiter $$\n");
+    sb.append("begin\n");
+    sb.append("if exists (select seqschema from syscat.sequences where seqschema = current_schema and seqname = '")
+        .append(maxConstraintName(sequenceName).toUpperCase()).append("') then\n");
+    sb.append("  prepare stmt from 'drop sequence ").append(maxConstraintName(sequenceName)).append("';\n");
+    sb.append("  execute stmt;\n");
+    sb.append("end if;\n");
+    sb.append("end$$");
+    return sb.toString();
+  }
+  
+  @Override
+  public String alterTableDropForeignKey(String tableName, String fkName) {
+    return alterTableDropConstraint(tableName, fkName);
+  }
+
+  @Override
+  public String alterTableDropConstraint(String tableName, String constraintName) {
+    StringBuilder sb = new StringBuilder(300);
+    sb.append("delimiter $$\n");
+    sb.append("begin\n");
+    sb.append("if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = '");
+    sb.append(maxConstraintName(constraintName).toUpperCase());
+    sb.append("' and tabname = '").append(lowerTableName(tableName).toUpperCase()).append("') then\n");
+    
+    sb.append("  prepare stmt from 'alter table ").append(lowerTableName(tableName));
+    sb.append(" drop constraint ").append(maxConstraintName(constraintName)).append("';\n");
+    
+    sb.append("  execute stmt;\n");
+    sb.append("end if;\n");
+    sb.append("end$$");
+    return sb.toString();
+  }
+  
+  @Override
+  public String dropIndex(String indexName, String tableName, boolean concurrent) {
+    StringBuilder sb = new StringBuilder(300);
+    sb.append("delimiter $$\n");
+    sb.append("begin\n");
+    sb.append("if exists (select indname from syscat.indexes where indschema = current_schema and indname = '");
+    sb.append(maxConstraintName(indexName).toUpperCase()).append("') then\n");
+
+    sb.append("  prepare stmt from 'drop index ").append(maxConstraintName(indexName)).append("';\n");
+    sb.append("  execute stmt;\n");
+    sb.append("end if;\n");
+    sb.append("end$$");
+    return sb.toString();
+  }
+
+  @Override
+  public String reorgTable(String table, int counter) {
+    // TODO Auto-generated method stub
+    return "call sysproc.admin_cmd('reorg table " + lowerTableName(table) + "') /* reorg #" + counter + " */";
+  }
+
 }

ebean-ddl-generator/src/main/java/io/ebeaninternal/dbmigration/ddlgeneration/platform/PlatformDdl.java

@@ -307,7 +307,7 @@ public class PlatformDdl {
    * Return the drop foreign key clause.
    */
   public String alterTableDropForeignKey(String tableName, String fkName) {
-    return "alter table " + alterTableIfExists + tableName + " " + dropConstraintIfExists + " " + maxConstraintName(fkName);
+    return "alter table " + alterTableIfExists + lowerTableName(tableName) + " " + dropConstraintIfExists + " " + maxConstraintName(fkName);
   }
 
   /**
@@ -772,4 +772,15 @@ public class PlatformDdl {
   public void addTablePartition(DdlBuffer apply, String partitionMode, String partitionColumn) throws IOException {
     // only supported by postgres initially
   }
+
+  /**
+   * Returns a statement to reorganize the table. This is required mainly for DB2.
+   * 
+   * @param table   the table name
+   * @param counter to make statements unique.
+   */
+  public String reorgTable(String table, int counter) {
+    return null;
+  }
+
 }

ebean-ddl-generator/src/test/java/io/ebeaninternal/dbmigration/DbMigrationTest.java

@@ -108,7 +108,7 @@ public class DbMigrationTest extends BaseTestCase {
 
     // Oracle caches the statement and does not detect schema change. It fails with
     // an ORA-01007
-    if (isOracle()) {
+    if (isOracle() || isDB2()) {
       result = server().sqlQuery("select * from migtest_e_basic order by id,id").findList();
     } else {
       result = server().sqlQuery("select * from migtest_e_basic order by id").findList();

ebean-ddl-generator/src/test/java/io/localtest/BaseTestCase.java

@@ -51,6 +51,10 @@ public abstract class BaseTestCase {
   public boolean isSqlServer() {
     return Platform.SQLSERVER == platform();
   }
+  
+  public boolean isDB2() {
+    return Platform.DB2 == platform();
+  }
 
   public boolean isH2() {
     return Platform.H2 == platform();

ebean-ddl-generator/src/test/java/misc/migration/v1_1/EBasic.java

@@ -5,6 +5,7 @@ import io.ebean.annotation.DbMigration;
 import io.ebean.annotation.EnumValue;
 import io.ebean.annotation.Index;
 import io.ebean.annotation.NotNull;
+import io.ebean.annotation.Platform;
 
 import javax.persistence.Column;
 import javax.persistence.Entity;
@@ -59,10 +60,11 @@ public class EBasic {
   @Size(max=127)
   String name;
 
-
+  @DbMigration(preAlter = { "-- db2 does not support parial null indices :( - so we have to clean",
+      "update ${table} set status = 'N' where id = 1" }, platforms = Platform.DB2)
   @DbMigration(preAlter = "-- rename all collisions")
   @Column(unique = true)
-  @Size(max=127)
+  @Size(max = 127)
   String description;
 
   //@NotNull

ebean-ddl-generator/src/test/resources/application-test.properties

@@ -1,12 +1,16 @@
 ebean.ddl.header=-- Generated by ebean ${version} at ${timestamp}
-ebean.ddl.generate=true
-ebean.ddl.run=true
-datasource.default=h2
+ebean.ddl.generate=false
+ebean.ddl.run=false
+datasource.default=db2
 
 datasource.h2.username=sa
 datasource.h2.password=
 datasource.h2.url=jdbc:h2:mem:h2AutoTune
 
+datasource.db2.username=migtest
+datasource.db2.password=migtest
+datasource.db2.url=jdbc:db2://localhost:50005/migtest
+
 datasource.pg.username=sa
 datasource.pg.password=
 datasource.pg.url=jdbc:h2:mem:h2AutoTune

ebean-ddl-generator/src/test/resources/dbinit/db2/1.4.sql

@@ -75,7 +75,9 @@ create table migtest_e_basic (
   constraint ck_migtest_e_basic_status2 check ( status2 in ('N','A','I')),
   constraint pk_migtest_e_basic primary key (id)
 );
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest2 on migtest_e_basic(indextest2) exclude null keys;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest6 on migtest_e_basic(indextest6) exclude null keys;
 
 create table migtest_e_enum (
@@ -129,6 +131,7 @@ create table migtest_e_ref (
   name                          varchar(127) not null,
   constraint pk_migtest_e_ref primary key (id)
 );
+-- alterTableAddUniqueConstraint 
 alter table migtest_e_ref add constraint uq_migtest_e_ref_name unique  (name);
 
 create table migtest_e_softdelete (

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/db2/1.0__initial.sql

@@ -75,7 +75,9 @@ create table migtest_e_basic (
   constraint ck_migtest_e_basic_status2 check ( status2 in ('N','A','I')),
   constraint pk_migtest_e_basic primary key (id)
 );
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest2 on migtest_e_basic(indextest2) exclude null keys;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest6 on migtest_e_basic(indextest6) exclude null keys;
 
 create table migtest_e_enum (
@@ -129,6 +131,7 @@ create table migtest_e_ref (
   name                          varchar(127) not null,
   constraint pk_migtest_e_ref primary key (id)
 );
+-- alterTableAddUniqueConstraint 
 alter table migtest_e_ref add constraint uq_migtest_e_ref_name unique  (name);
 
 create table migtest_e_softdelete (

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/db2/1.1.sql

@@ -23,31 +23,59 @@ alter table migtest_ckey_detail add column two_key varchar(127);
 alter table migtest_ckey_detail add constraint fk_migtest_ckey_detail_parent foreign key (one_key,two_key) references migtest_ckey_parent (one_key,two_key) on delete restrict;
 alter table migtest_ckey_parent add column assoc_id integer;
 
-alter table migtest_fk_cascade drop constraint fk_migtest_fk_cascade_one_id;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_FK_CASCADE_ONE_ID' and tabname = 'MIGTEST_FK_CASCADE') then
+  prepare stmt from 'alter table migtest_fk_cascade drop constraint fk_migtest_fk_cascade_one_id';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_fk_cascade add constraint fk_migtest_fk_cascade_one_id foreign key (one_id) references migtest_fk_cascade_one (id) on delete restrict;
 alter table migtest_fk_none add constraint fk_migtest_fk_none_one_id foreign key (one_id) references migtest_fk_one (id) on delete restrict;
 alter table migtest_fk_none_via_join add constraint fk_migtest_fk_none_via_join_one_id foreign key (one_id) references migtest_fk_one (id) on delete restrict;
-alter table migtest_fk_set_null drop constraint fk_migtest_fk_set_null_one_id;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_FK_SET_NULL_ONE_ID' and tabname = 'MIGTEST_FK_SET_NULL') then
+  prepare stmt from 'alter table migtest_fk_set_null drop constraint fk_migtest_fk_set_null_one_id';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_fk_set_null add constraint fk_migtest_fk_set_null_one_id foreign key (one_id) references migtest_fk_one (id) on delete restrict;
 
 update migtest_e_basic set status = 'A' where status is null;
-alter table migtest_e_basic drop constraint ck_migtest_e_basic_status;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'CK_MIGTEST_E_BASIC_STATUS' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint ck_migtest_e_basic_status';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_e_basic alter column status set default 'A';
 alter table migtest_e_basic alter column status set not null;
 alter table migtest_e_basic add constraint ck_migtest_e_basic_status check ( status in ('N','A','I','?'));
-alter table migtest_e_basic drop constraint ck_migtest_e_basic_status2;
-alter table migtest_e_basic alter column status2 varchar(127);
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'CK_MIGTEST_E_BASIC_STATUS2' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint ck_migtest_e_basic_status2';
+  execute stmt;
+end if;
+end$$;
+alter table migtest_e_basic alter column status2 set data type varchar(127);
 alter table migtest_e_basic alter column status2 drop default;
-alter table migtest_e_basic alter column status2 set null;
+alter table migtest_e_basic alter column status2 drop not null;
 
--- rename all collisions;
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #1 */;
+-- db2 does not support parial null indices :( - so we have to clean;
+update migtest_e_basic set status = 'N' where id = 1;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_description on migtest_e_basic(description) exclude null keys;
 
 insert into migtest_e_user (id) select distinct user_id from migtest_e_basic;
 alter table migtest_e_basic add constraint fk_migtest_e_basic_user_id foreign key (user_id) references migtest_e_user (id) on delete restrict;
-alter table migtest_e_basic alter column user_id set null;
+alter table migtest_e_basic alter column user_id drop not null;
 alter table migtest_e_basic add column new_string_field varchar(255) default 'foo''bar' not null;
 alter table migtest_e_basic add column new_boolean_field boolean default true not null;
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #2 */;
 update migtest_e_basic set new_boolean_field = old_boolean;
 
 alter table migtest_e_basic add column new_boolean_field2 boolean default true not null;
@@ -55,17 +83,54 @@ alter table migtest_e_basic add column progress integer default 0 not null;
 alter table migtest_e_basic add constraint ck_migtest_e_basic_progress check ( progress in (0,1,2));
 alter table migtest_e_basic add column new_integer integer default 42 not null;
 
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest2;
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest6;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_INDEXTEST2' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest2';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_INDEXTEST2') then
+  prepare stmt from 'drop index uq_migtest_e_basic_indextest2';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_INDEXTEST6' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest6';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_INDEXTEST6') then
+  prepare stmt from 'drop index uq_migtest_e_basic_indextest6';
+  execute stmt;
+end if;
+end$$;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_status_indextest1 on migtest_e_basic(status,indextest1) exclude null keys;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_name on migtest_e_basic(name) exclude null keys;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest4 on migtest_e_basic(indextest4) exclude null keys;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest5 on migtest_e_basic(indextest5) exclude null keys;
-alter table migtest_e_enum drop constraint ck_migtest_e_enum_test_status;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'CK_MIGTEST_E_ENUM_TEST_STATUS' and tabname = 'MIGTEST_E_ENUM') then
+  prepare stmt from 'alter table migtest_e_enum drop constraint ck_migtest_e_enum_test_status';
+  execute stmt;
+end if;
+end$$;
 comment on column migtest_e_history.test_string is 'Column altered to long now';
-alter table migtest_e_history alter column test_string bigint;
+alter table migtest_e_history alter column test_string set data type bigint;
 comment on table migtest_e_history is 'We have history now';
 
+call sysproc.admin_cmd('reorg table migtest_e_history') /* reorg #3 */;
 -- NOTE: table has @History - special migration may be necessary
 update migtest_e_history2 set test_string = 'unknown' where test_string is null;
 alter table migtest_e_history2 alter column test_string set default 'unknown';
@@ -74,23 +139,38 @@ alter table migtest_e_history2 add column test_string2 varchar(255);
 alter table migtest_e_history2 add column test_string3 varchar(255) default 'unknown' not null;
 alter table migtest_e_history2 add column new_column varchar(20);
 
-alter table migtest_e_history4 alter column test_number bigint;
+alter table migtest_e_history4 alter column test_number set data type bigint;
 alter table migtest_e_history5 add column test_boolean boolean default false not null;
 
 
+call sysproc.admin_cmd('reorg table migtest_e_history2') /* reorg #4 */;
+call sysproc.admin_cmd('reorg table migtest_e_history4') /* reorg #5 */;
 -- NOTE: table has @History - special migration may be necessary
 update migtest_e_history6 set test_number1 = 42 where test_number1 is null;
 alter table migtest_e_history6 alter column test_number1 set default 42;
 alter table migtest_e_history6 alter column test_number1 set not null;
-alter table migtest_e_history6 alter column test_number2 set null;
+alter table migtest_e_history6 alter column test_number2 drop not null;
 alter table migtest_e_softdelete add column deleted boolean default false not null;
 
 alter table migtest_oto_child add column master_id bigint;
 
+call sysproc.admin_cmd('reorg table migtest_e_history6') /* reorg #6 */;
 create index ix_migtest_e_basic_indextest3 on migtest_e_basic (indextest3);
 create index ix_migtest_e_basic_indextest6 on migtest_e_basic (indextest6);
-drop index ix_migtest_e_basic_indextest1;
-drop index ix_migtest_e_basic_indextest5;
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'IX_MIGTEST_E_BASIC_INDEXTEST1') then
+  prepare stmt from 'drop index ix_migtest_e_basic_indextest1';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'IX_MIGTEST_E_BASIC_INDEXTEST5') then
+  prepare stmt from 'drop index ix_migtest_e_basic_indextest5';
+  execute stmt;
+end if;
+end$$;
 create index ix_migtest_mtm_c_migtest_mtm_m_migtest_mtm_c on migtest_mtm_c_migtest_mtm_m (migtest_mtm_c_id);
 alter table migtest_mtm_c_migtest_mtm_m add constraint fk_migtest_mtm_c_migtest_mtm_m_migtest_mtm_c foreign key (migtest_mtm_c_id) references migtest_mtm_c (id) on delete restrict;
 

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/db2/1.2__dropsFor_1.1.sql

@@ -11,4 +11,12 @@ alter table migtest_e_history2 drop column obsolete_string1;
 alter table migtest_e_history2 drop column obsolete_string2;
 
 drop table migtest_e_ref;
-drop sequence migtest_e_ref_seq;
+delimiter $$
+begin
+if exists (select seqschema from syscat.sequences where seqschema = current_schema and seqname = 'MIGTEST_E_REF_SEQ') then
+  prepare stmt from 'drop sequence migtest_e_ref_seq';
+  execute stmt;
+end if;
+end$$;
+call sysproc.admin_cmd('reorg table migtest_e_history2') /* reorg #1 */;
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #2 */;

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/db2/1.3.sql

@@ -5,63 +5,204 @@ create table migtest_e_ref (
   name                          varchar(127) not null,
   constraint pk_migtest_e_ref primary key (id)
 );
+-- alterTableAddUniqueConstraint 
 alter table migtest_e_ref add constraint uq_migtest_e_ref_name unique  (name);
 
-alter table migtest_ckey_detail drop constraint fk_migtest_ckey_detail_parent;
-alter table migtest_fk_cascade drop constraint fk_migtest_fk_cascade_one_id;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_CKEY_DETAIL_PARENT' and tabname = 'MIGTEST_CKEY_DETAIL') then
+  prepare stmt from 'alter table migtest_ckey_detail drop constraint fk_migtest_ckey_detail_parent';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_FK_CASCADE_ONE_ID' and tabname = 'MIGTEST_FK_CASCADE') then
+  prepare stmt from 'alter table migtest_fk_cascade drop constraint fk_migtest_fk_cascade_one_id';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_fk_cascade add constraint fk_migtest_fk_cascade_one_id foreign key (one_id) references migtest_fk_cascade_one (id) on delete cascade;
-alter table migtest_fk_none drop constraint fk_migtest_fk_none_one_id;
-alter table migtest_fk_none_via_join drop constraint fk_migtest_fk_none_via_join_one_id;
-alter table migtest_fk_set_null drop constraint fk_migtest_fk_set_null_one_id;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_FK_NONE_ONE_ID' and tabname = 'MIGTEST_FK_NONE') then
+  prepare stmt from 'alter table migtest_fk_none drop constraint fk_migtest_fk_none_one_id';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_FK_NONE_VIA_JOIN_ONE_ID' and tabname = 'MIGTEST_FK_NONE_VIA_JOIN') then
+  prepare stmt from 'alter table migtest_fk_none_via_join drop constraint fk_migtest_fk_none_via_join_one_id';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_FK_SET_NULL_ONE_ID' and tabname = 'MIGTEST_FK_SET_NULL') then
+  prepare stmt from 'alter table migtest_fk_set_null drop constraint fk_migtest_fk_set_null_one_id';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_fk_set_null add constraint fk_migtest_fk_set_null_one_id foreign key (one_id) references migtest_fk_one (id) on delete set null;
-alter table migtest_e_basic drop constraint ck_migtest_e_basic_status;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'CK_MIGTEST_E_BASIC_STATUS' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint ck_migtest_e_basic_status';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_e_basic alter column status drop default;
-alter table migtest_e_basic alter column status set null;
+alter table migtest_e_basic alter column status drop not null;
 alter table migtest_e_basic add constraint ck_migtest_e_basic_status check ( status in ('N','A','I'));
 
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #1 */;
 update migtest_e_basic set status2 = 'N' where status2 is null;
-alter table migtest_e_basic drop constraint ck_migtest_e_basic_status2;
-alter table migtest_e_basic alter column status2 varchar(1);
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'CK_MIGTEST_E_BASIC_STATUS2' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint ck_migtest_e_basic_status2';
+  execute stmt;
+end if;
+end$$;
+alter table migtest_e_basic alter column status2 set data type varchar(1);
 alter table migtest_e_basic alter column status2 set default 'N';
 alter table migtest_e_basic alter column status2 set not null;
 alter table migtest_e_basic add constraint ck_migtest_e_basic_status2 check ( status2 in ('N','A','I'));
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_description;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_DESCRIPTION' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_description';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_DESCRIPTION') then
+  prepare stmt from 'drop index uq_migtest_e_basic_description';
+  execute stmt;
+end if;
+end$$;
 
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #2 */;
 update migtest_e_basic set user_id = 23 where user_id is null;
-alter table migtest_e_basic drop constraint fk_migtest_e_basic_user_id;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'FK_MIGTEST_E_BASIC_USER_ID' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint fk_migtest_e_basic_user_id';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_e_basic alter column user_id set default 23;
 alter table migtest_e_basic alter column user_id set not null;
 alter table migtest_e_basic add column old_boolean boolean default false not null;
 alter table migtest_e_basic add column old_boolean2 boolean;
 alter table migtest_e_basic add column eref_id integer;
 
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_status_indextest1;
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_name;
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest4;
-alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest5;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_STATUS_INDEXTEST1' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_status_indextest1';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_STATUS_INDEXTEST1') then
+  prepare stmt from 'drop index uq_migtest_e_basic_status_indextest1';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_NAME' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_name';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_NAME') then
+  prepare stmt from 'drop index uq_migtest_e_basic_name';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_INDEXTEST4' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest4';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_INDEXTEST4') then
+  prepare stmt from 'drop index uq_migtest_e_basic_indextest4';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'UQ_MIGTEST_E_BASIC_INDEXTEST5' and tabname = 'MIGTEST_E_BASIC') then
+  prepare stmt from 'alter table migtest_e_basic drop constraint uq_migtest_e_basic_indextest5';
+  execute stmt;
+end if;
+end$$
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'UQ_MIGTEST_E_BASIC_INDEXTEST5') then
+  prepare stmt from 'drop index uq_migtest_e_basic_indextest5';
+  execute stmt;
+end if;
+end$$;
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #3 */;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest2 on migtest_e_basic(indextest2) exclude null keys;
+-- alterTableAddUniqueConstraint 
 create unique index uq_migtest_e_basic_indextest6 on migtest_e_basic(indextest6) exclude null keys;
-alter table migtest_e_enum drop constraint ck_migtest_e_enum_test_status;
+delimiter $$
+begin
+if exists (select constname from syscat.tabconst where tabschema = current_schema and constname = 'CK_MIGTEST_E_ENUM_TEST_STATUS' and tabname = 'MIGTEST_E_ENUM') then
+  prepare stmt from 'alter table migtest_e_enum drop constraint ck_migtest_e_enum_test_status';
+  execute stmt;
+end if;
+end$$;
 alter table migtest_e_enum add constraint ck_migtest_e_enum_test_status check ( test_status in ('N','A','I'));
 comment on column migtest_e_history.test_string is '';
 comment on table migtest_e_history is '';
 alter table migtest_e_history2 alter column test_string drop default;
-alter table migtest_e_history2 alter column test_string set null;
+alter table migtest_e_history2 alter column test_string drop not null;
 alter table migtest_e_history2 add column obsolete_string1 varchar(255);
 alter table migtest_e_history2 add column obsolete_string2 varchar(255);
 
-alter table migtest_e_history4 alter column test_number integer;
+alter table migtest_e_history4 alter column test_number set data type integer;
 alter table migtest_e_history6 alter column test_number1 drop default;
-alter table migtest_e_history6 alter column test_number1 set null;
+alter table migtest_e_history6 alter column test_number1 drop not null;
 
+call sysproc.admin_cmd('reorg table migtest_e_history2') /* reorg #4 */;
+call sysproc.admin_cmd('reorg table migtest_e_history6') /* reorg #5 */;
+call sysproc.admin_cmd('reorg table migtest_e_history4') /* reorg #6 */;
 -- NOTE: table has @History - special migration may be necessary
 update migtest_e_history6 set test_number2 = 7 where test_number2 is null;
 alter table migtest_e_history6 alter column test_number2 set default 7;
 alter table migtest_e_history6 alter column test_number2 set not null;
+call sysproc.admin_cmd('reorg table migtest_e_history6') /* reorg #7 */;
 create index ix_migtest_e_basic_indextest1 on migtest_e_basic (indextest1);
 create index ix_migtest_e_basic_indextest5 on migtest_e_basic (indextest5);
-drop index ix_migtest_e_basic_indextest3;
-drop index ix_migtest_e_basic_indextest6;
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'IX_MIGTEST_E_BASIC_INDEXTEST3') then
+  prepare stmt from 'drop index ix_migtest_e_basic_indextest3';
+  execute stmt;
+end if;
+end$$;
+delimiter $$
+begin
+if exists (select indname from syscat.indexes where indschema = current_schema and indname = 'IX_MIGTEST_E_BASIC_INDEXTEST6') then
+  prepare stmt from 'drop index ix_migtest_e_basic_indextest6';
+  execute stmt;
+end if;
+end$$;
 create index ix_migtest_e_basic_eref_id on migtest_e_basic (eref_id);
 alter table migtest_e_basic add constraint fk_migtest_e_basic_eref_id foreign key (eref_id) references migtest_e_ref (id) on delete restrict;
 

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/db2/1.4__dropsFor_1.3.sql

@@ -29,6 +29,19 @@ alter table migtest_e_softdelete drop column deleted;
 alter table migtest_oto_child drop column master_id;
 
 drop table migtest_e_user;
-drop sequence migtest_e_user_seq;
+delimiter $$
+begin
+if exists (select seqschema from syscat.sequences where seqschema = current_schema and seqname = 'MIGTEST_E_USER_SEQ') then
+  prepare stmt from 'drop sequence migtest_e_user_seq';
+  execute stmt;
+end if;
+end$$;
 drop table migtest_mtm_c_migtest_mtm_m;
 drop table migtest_mtm_m_migtest_mtm_c;
+call sysproc.admin_cmd('reorg table migtest_e_history2') /* reorg #1 */;
+call sysproc.admin_cmd('reorg table migtest_e_softdelete') /* reorg #2 */;
+call sysproc.admin_cmd('reorg table migtest_oto_child') /* reorg #3 */;
+call sysproc.admin_cmd('reorg table migtest_ckey_parent') /* reorg #4 */;
+call sysproc.admin_cmd('reorg table migtest_e_history5') /* reorg #5 */;
+call sysproc.admin_cmd('reorg table migtest_ckey_detail') /* reorg #6 */;
+call sysproc.admin_cmd('reorg table migtest_e_basic') /* reorg #7 */;

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/db2/idx_db2.migrations

@@ -1,6 +1,6 @@
-1580812656,     1.0__initial.sql
--522424232,     1.1.sql
-578073685,      1.2__dropsFor_1.1.sql
--1685257725,    1.3.sql
--1475628451,    1.4__dropsFor_1.3.sql
+997100585,      1.0__initial.sql
+855187652,      1.1.sql
+1091886546,     1.2__dropsFor_1.1.sql
+-364921922,     1.3.sql
+2020621716,     1.4__dropsFor_1.3.sql
 

ebean-ddl-generator/src/test/resources/dbmigration/migrationtest/model/1.1.model.xml

@@ -16,6 +16,10 @@
         <alterColumn columnName="status" tableName="migtest_e_basic" currentType="varchar(1)" defaultValue="'A'" notnull="true" currentNotnull="false" checkConstraint="check ( status in ('N','A','I','?'))" checkConstraintName="ck_migtest_e_basic_status"/>
         <alterColumn columnName="status2" tableName="migtest_e_basic" type="varchar(127)" currentType="varchar(1)" defaultValue="DROP DEFAULT" notnull="false" currentNotnull="true" dropCheckConstraint="ck_migtest_e_basic_status2"/>
         <alterColumn columnName="description" tableName="migtest_e_basic" unique="uq_migtest_e_basic_description">
+            <before platforms="db2">
+                <ddl>-- db2 does not support parial null indices :( - so we have to clean</ddl>
+                <ddl>update ${table} set status = 'N' where id = 1</ddl>
+            </before>
             <before>
                 <ddl>-- rename all collisions</ddl>
             </before>