Home >

Flyway

Flyway provides the means to manage schema changes to a YugabyteDB database, among others.

The YugabyteDB-specific implementation of the Flyway APIs has been added to the Flyway community project.

Prerequisites

Before you can start using Flyway, ensure that you have the following installed and configured:

YugabyteDB version 2.4 or later (see YugabyteDB Quick Start Guide).
Yugabyte cluster (see Create a local cluster).
Flyway community edition version 7.11.2 or later (see Download Flyway).
Connection details in the Flyway configuration file conf/flyway.conf. Append the following at the end of the file, replacing flyway.url with the URL of your running YugabyteDB cluster:
```
flyway.url=jdbc:postgresql://localhost:5433/yugabyte
flyway.user=yugabyte
flyway.password=yugabyte
```

Migrating schema

Flyway allows you to specify migrations using either SQL or Java.

Note

By default, Flyway runs migrations inside a transaction. In case of failures, the transaction is rolled back (see Flyway Transactions). Since YugabyteDB does not currently support DDLs inside a user-initiated transaction (instead, it runs a DDL inside an implicit transaction), you may need to manually revert the DDL changes when you see a message about failed migrations “Please restore backups and roll back database and code”.

How to use SQL

You can specify migrations as SQL statements in .sql files that are placed in the <FLYWAY_INSTALL_DIR>/sql/ directory by default. You can change the location of these files by placing them in a different directory and then editing the flyway.locations property in the flyway.conf file accordingly.

To migrate schema using SQL, perform the following:

Create migration SQL scripts under the sql/ directory, as shown in the following example using the motorcycle_manufacturers table:

cat sql/Create_motorcycle_manufacturers_table.sql

CREATE TABLE motorcycle_manufacturers (
  manufacturer_id SERIAL PRIMARY KEY,
  manufacturer_name VARCHAR(50) NOT NULL
);

cat V2__Insert_into_motorcycle_manufacturers.sql

INSERT INTO motorcycle_manufacturers (manufacturer_id, manufacturer_name) 
VALUES (default, 'Harley-Davidson'), (default, 'Yamaha');

Run migrations by executing the following command:
```
 ./flyway migrate
```

How to use Java

You can define Flyway migrations as Java classes by extending the BaseJavaMigration class and overriding the migrate() method.

The following example shows how to use Java to add a column called hq_address to the motorcycle_manufacturers table:

package db.migration;

import org.flywaydb.core.api.migration.BaseJavaMigration;
import org.flywaydb.core.api.migration.Context;
import java.sql.Statement;

public class V3__AddHQAdress extends BaseJavaMigration {

  public void migrate(Context context) throws Exception {
    try (Statement alter = context.getConnection().createStatement()) {
      alter.execute("ALTER TABLE motorcycle_manufacturers 
                    ADD COLUMN hq_address VARCHAR(50)");
    }                   
  }
}

After you compile the Java class, place its JAR in the <FLYWAY_INSTALL_DIR>/jars/ directory, as this is the default location for Flyway to look for Java migration JARs. If you want to use a different location, you need to specify the JAR path by editing the flyway.locations property in the flyway.conf file.

To check the state of the database and run the migration, execute the following commands:

 ./flyway info

 ./flyway migrate