All Known Implementing Classes:

DefaultDbMigration
```
public interface DbMigration
```
Generates DDL migration scripts based on changes to the current model.
Typically this is run as a main method in src/test once a developer is happy with the next set of changes to the model.
Example: Run for a single specific platform
```
    DbMigration migration = DbMigration.create();

    migration.setPlatform(Platform.POSTGRES);

    // optionally specify the version and name
    migration.setName("add indexes to customer");

    migration.generateMigration();

 
```
Drop column migrations are effectively breaking changes and should be held back and run in a later migration after the columns deleted are no longer being used by the application. These changes are called "pending drops" and we must explicitly specify to include these in a generated migration.
Use setGeneratePendingDrop() to specify a prior migration that has drop column changes that we want to generate a migration for.
Example: Generate for pending drops
```
    DbMigration migration = DbMigration.create();

    migration.setPlatform(Platform.POSTGRES);

    // set the migration version that has pending drops
    migration.setGeneratePendingDrop("1.3");

    // generates the migration with drop column changes
    migration.generateMigration();

 
```

Method Summary

All Methods Static Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`addDatabasePlatform(io.ebean.config.dbplatform.DatabasePlatform databasePlatform, String prefix)`	Add a databasePlatform to write the migration DDL.
`void`	`addPlatform(io.ebean.annotation.Platform platform)`	Add a platform to write the migration DDL.
`void`	`addPlatform(io.ebean.annotation.Platform platform, String prefix)`	Add a platform to write with a given prefix.
`static DbMigration`	`create()`	Create a DbMigration implementation to use.
`String`	`generateInitMigration()`	Generate an "init" migration which has all changes.
`String`	`generateMigration()`	Generate the next migration sql script and associated model xml.
`List<String>`	`getPendingDrops()`	Return the list of versions that contain pending drops.
`void`	`setAddForeignKeySkipCheck(boolean addForeignKeySkipCheck)`	Set to true if ALTER TABLE ADD FOREIGN KEY should be generated with an option to skip validation.
`void`	`setApplyPrefix(String applyPrefix)`	Set the prefix for the version.
`void`	`setGeneratePendingDrop(String generatePendingDrop)`	Generate a migration for the version specified that contains pending drops.
`void`	`setHeader(String header)`	Set the header that is included in the generated DDL script.
`void`	`setIncludeBuiltInPartitioning(boolean includeBuiltInPartitioning)`	Set this to false to exclude the builtin support for table partitioning (with @DbPartition).
`void`	`setIncludeGeneratedFileComment(boolean includeGeneratedFileComment)`	Set to true to include a generated header comment in the DDL script.
`void`	`setIncludeIndex(boolean generateIndexFile)`	Set to include generation of the index migration file.
`void`	`setLockTimeout(int seconds)`	Set the lock timeout to be included with the DDL generation.
`void`	`setLogToSystemOut(boolean logToSystemOut)`	Set logging to System out (defaults to true).
`void`	`setMigrationPath(String migrationPath)`	Set the path where migrations are generated to (which defaults to "dbmigration").
`void`	`setName(String name)`	Set the name of the migration to be generated.
`void`	`setPathToResources(String pathToResources)`	Set the path from the current working directory to the application resources.
`void`	`setPlatform(io.ebean.annotation.Platform platform)`	Set the specific platform to generate DDL for.
`void`	`setPlatform(io.ebean.config.dbplatform.DatabasePlatform databasePlatform)`	Set the specific platform to generate DDL for.
`void`	`setServer(io.ebean.Database database)`	Set the server to use to determine the current model.
`void`	`setServerConfig(io.ebean.config.DatabaseConfig config)`	Set the DatabaseConfig to use.
`void`	`setStrictMode(boolean strictMode)`	Set to false in order to turn off strict mode.
`void`	`setVersion(String version)`	Set the version of the migration to be generated.

- Method Detail
  - create
```
static DbMigration create()
```
    Create a DbMigration implementation to use.
  - setLogToSystemOut
```
void setLogToSystemOut(boolean logToSystemOut)
```
    Set logging to System out (defaults to true).
  - setPathToResources
```
void setPathToResources(String pathToResources)
```
    Set the path from the current working directory to the application resources.
    This defaults to maven style 'src/main/resources'.
  - setMigrationPath
```
void setMigrationPath(String migrationPath)
```
    Set the path where migrations are generated to (which defaults to "dbmigration").
    Normally we only use this when we use Ebean to generate the database migrations and then use some other tool like FlywayDB to run the migrations.
    Example: with setMigrationPath("db/migration") ... the migrations are generated into src/resources/db/migration.
    Note that if Ebean migration runner is used we should not use this method but instead set the migrationPath via a property such that both the migration generator and migration runner both use the same path.
    
    Parameters:
    
    migrationPath - The path that migrations are generated into.
  - setServer
```
void setServer(io.ebean.Database database)
```
    Set the server to use to determine the current model. Usually this is not called explicitly.
  - setServerConfig
```
void setServerConfig(io.ebean.config.DatabaseConfig config)
```
    Set the DatabaseConfig to use. Usually this is not called explicitly.
  - setPlatform
```
void setPlatform(io.ebean.annotation.Platform platform)
```
    Set the specific platform to generate DDL for.
    If not set this defaults to the platform of the default database.
  - setPlatform
```
void setPlatform(io.ebean.config.dbplatform.DatabasePlatform databasePlatform)
```
    Set the specific platform to generate DDL for.
    If not set this defaults to the platform of the default database.
  - setStrictMode
```
void setStrictMode(boolean strictMode)
```
    Set to false in order to turn off strict mode.
    Strict mode checks that a column changed to non-null on an existing table via DB migration has a default value specified. Set this to false if that isn't the case but it is known that all the existing rows have a value specified (there are no existing null values for the column).
  - setIncludeIndex
```
void setIncludeIndex(boolean generateIndexFile)
```
    Set to include generation of the index migration file.
    When true this generates a idx_<platform>.migrations file. This can be used by the migration runner to improve performance of running migrations, especially when no migration changes have occurred.
  - setIncludeGeneratedFileComment
```
void setIncludeGeneratedFileComment(boolean includeGeneratedFileComment)
```
    Set to true to include a generated header comment in the DDL script.
  - setIncludeBuiltInPartitioning
```
void setIncludeBuiltInPartitioning(boolean includeBuiltInPartitioning)
```
    Set this to false to exclude the builtin support for table partitioning (with @DbPartition).
  - setHeader
```
void setHeader(String header)
```
    Set the header that is included in the generated DDL script.
  - setApplyPrefix
```
void setApplyPrefix(String applyPrefix)
```
    Set the prefix for the version. Set this to "V" for use with Flyway.
  - setVersion
```
void setVersion(String version)
```
    Set the version of the migration to be generated.
  - setName
```
void setName(String name)
```
    Set the name of the migration to be generated.
  - setGeneratePendingDrop
```
void setGeneratePendingDrop(String generatePendingDrop)
```
    Generate a migration for the version specified that contains pending drops.
    
    Parameters:
    
    generatePendingDrop - The version of a prior migration that holds pending drops.
  - setAddForeignKeySkipCheck
```
void setAddForeignKeySkipCheck(boolean addForeignKeySkipCheck)
```
    Set to true if ALTER TABLE ADD FOREIGN KEY should be generated with an option to skip validation.
    Currently this is only useful for Postgres DDL adding the NOT VALID option.
  - setLockTimeout
```
void setLockTimeout(int seconds)
```
    Set the lock timeout to be included with the DDL generation.
    Currently this is only useful for Postgres migrations adding a set lock_timeout statement to the generated database migration.
  - addPlatform
```
void addPlatform(io.ebean.annotation.Platform platform)
```
    Add a platform to write the migration DDL.
    Use this when you want to generate sql scripts for multiple database platforms from the migration (e.g. generate migration sql for MySql, Postgres and Oracle).
  - addPlatform
```
void addPlatform(io.ebean.annotation.Platform platform,
                 String prefix)
```
    Add a platform to write with a given prefix.
  - addDatabasePlatform
```
void addDatabasePlatform(io.ebean.config.dbplatform.DatabasePlatform databasePlatform,
                         String prefix)
```
    Add a databasePlatform to write the migration DDL.
    Use this when you want to add preconfigured database platforms.
  - getPendingDrops
```
List<String> getPendingDrops()
```
    Return the list of versions that contain pending drops.
  - generateMigration
```
String generateMigration()
                  throws IOException
```
    Generate the next migration sql script and associated model xml.
    This does not run the migration or ddl scripts but just generates them.
    
    Example: Run for a single specific platform
    
    DbMigration migration = DbMigration.create(); migration.setPlatform(Platform.POSTGRES); migration.generateMigration();
    
    Example: Generate for "pending drops" (drop column changes)
    
    DbMigration migration = DbMigration.create(); migration.setPlatform(Platform.POSTGRES); // set the migration version that has pending drops migration.setGeneratePendingDrop("1.3"); // generates the migration with drop column changes migration.generateMigration();
    
    Example: Run migration generating DDL for multiple platforms
    
    DbMigration migration = DbMigration.create(); migration.setPathToResources("src/main/resources"); migration.addPlatform(Platform.POSTGRES); migration.addPlatform(Platform.MYSQL); migration.addPlatform(Platform.ORACLE); migration.generateMigration();
    Returns:
    
    the version of the generated migration or null
    
    Throws:
    
    IOException
  - generateInitMigration
```
String generateInitMigration()
                      throws IOException
```
    Generate an "init" migration which has all changes.
    An "init" migration can only be executed and used on a database that has had no prior migrations run on it.
    
    Returns:
    
    the version of the generated migration
    
    Throws:
    
    IOException

Interface DbMigration

Example: Run for a single specific platform

Example: Generate for pending drops

Method Summary

Method Detail

create

setLogToSystemOut

setPathToResources

setMigrationPath

setServer

setServerConfig

setPlatform

setPlatform

setStrictMode

setIncludeIndex

setIncludeGeneratedFileComment

setIncludeBuiltInPartitioning

setHeader

setApplyPrefix

setVersion

setName

setGeneratePendingDrop

setAddForeignKeySkipCheck

setLockTimeout

addPlatform

addPlatform

addDatabasePlatform

getPendingDrops

generateMigration

Example: Run for a single specific platform

Example: Generate for "pending drops" (drop column changes)

Example: Run migration generating DDL for multiple platforms

generateInitMigration