Liquibase
always suggests including a rollback
in ChangeSet
, so in case of error, ChangeSets
can be rollback
to previous states. Liquibase
base provides rollbackSql
that helps to inspect what query will be fired when rollback
will execute for the ChangeSets
, which are already executed.
Sometimes the requirement is to know what rollback
queries will be fired by Liquibase
in case of rollback
for the ChangeSet
which are in ChangeLog
file but not executed yet. for this purpose, Liquibase
provides futureRollbackSql
helper command, it will provide a rollback
script for the ChangeSet
which has not been executed yet.
<?xml version="1.1" encoding="UTF-8" standalone="no"?>
<databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog" xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext" xmlns:pro="http://www.liquibase.org/xml/ns/pro" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog-ext http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd http://www.liquibase.org/xml/ns/pro http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd">
<changeSet author="wesome" id="1692446190573-1">
<createTable catalogName="appledb" tableName="apple">
<column autoIncrement="true" name="apple_id" type="BIGINT">
<constraints nullable="false" primaryKey="true" />
</column>
<column name="apple_name" type="VARCHAR(255)" />
<column defaultValueComputed="CURRENT_TIMESTAMP" name="current_date_time" type="datetime" />
</createTable>
<rollback>
<dropTable tableName="apple" />
</rollback>
</changeSet>
<changeSet author="wesome" id="1692701200879-2">
<insert catalogName="appledb" tableName="apple">
<column name="apple_name" value="Fuji" />
<column name="current_date_time" valueDate="now()" />
</insert>
<rollback>
<delete tableName="apple">
<where>
apple_name = 'Fuji'
</where>
</delete>
</rollback>
</changeSet>
<changeSet author="wesome" id="1692701200879-3">
<insert catalogName="appledb" tableName="apple">
<column name="apple_name" value="Gala" />
<column name="current_date_time" valueDate="now()" />
</insert>
<rollback>
<delete tableName="apple">
<where>
apple_name = 'Gala'
</where>
</delete>
</rollback>
</changeSet>
</databaseChangeLog>
liquibase.properties (update changeLog File file format with SQL, XML, YAML, JSON as per changelog.mysql.)
changeLogFile=changelog.mysql.xml
liquibase.command.url:jdbc:mysql://localhost:3306/appleDb?createDatabaseIfNotExist=true&autoReconnect=true&useSSL=false&allowPublicKeyRetrieval=true
liquibase.command.username : root
liquibase.command.password : rootroot
Run command liquibase update --count=2
The table is created with only the first 2 ChangeSet
records, the same can be verified by running the query
SELECT * FROM appleDb.apple;
now to inspect the SQL
query for yet to be executed ChangeSet
, run the command liquibase futureRollbackSql