Liquibase ask for fully defined schema Name, for example for the indexExists tag. But what if want to run a changeset on multiple schema. Is there a way to indicate running on the current schema, or to dynamically set it when running an update ?
My Bad, that schemaName is not a required attribute for createIndex.
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I have one enviornment in which queries containing more than 100 tables. now i need to access same query in read only environment. so i need to use <schema_name>.<table_name> in read only env. This is read only env so i can not create synonyms for all.
instead of writing schema name in prefix of each table, Is there any short cut for it. i am just guessing if anything is possible? They all belongs to same schema.
Try this out. It will set your session environment to the specified schema and as consequence, no need to provide the <schema_name> prefix.
ALTER SESSION SET CURRENT_SCHEMA = <schema_name>;
Difference Between setDefaultSchemaName() and setLiquibaseSchemaName() in Liquibase?
What is the use of both the methods in Liquibase ?
The default schema is the schema managed by Liquibase - i.e. when you create a table, it will be created the the default schema. The Liquibase schema name is where the Liquibase control tables (DATABASECHANGELOG and DATABASECHANGELOGLOCK) are kept.
Is there anyway to reference the changeLog id in your sql? We're in the middle of moving our database over to liquibase, but we already have an Environment table which has key value pairs, one of which is "database_version". I want all our liquibase changes to also update the value for the "database_version" with the change_log id.
There is nothing built in, but the extension system (http://liquibase.org/extensions) will allow you to implement it yourself.
The easiest approach would probably be to add a liquibase.changelog.visitor.ChangeExecListener implementation updates your table after each change is executed.
In our case liquibase is used to update databses for existing installation. New installations are already up to date.
Assuming we have got a new installation. Starting the application will force to execute liquibase changesets (e.g. change type of a column) but as I mentioned before there is nothing to update as the column already was created with the correct type.
Does liquibase recognize that the table column is already up to date or does it try to execute the changeset as there is no entry within the databasechangelog table for it?
Liquibase uses an alternative approach that avoids a need to analyze the target database's data dictionary. This makes DB operations simpler and more cross platform.
A special table "DATABASECHANGELOG" keeps a record of the changesets applied to the target database instance. This table also contains a checksum (calculated at runtime) to determine if changsets are altered between runs of liquibase.
So if you altered the type of a table column, liquibase can detect this and can throw an error, when run against an existing database. (Obviously, on a new DB, the table would be created as expected).
Finally, the changeset documentation describes two optional attributes ("runAlways" and "runOnChange") which could tell lqiuibase to reapply a changeset more than once to a database. There is also a "clearCheckSums" command that can be used to reset the checksums on an existing database. Obviously you need to know what you're doing when using such an option :-)
Liquibase will not recognize anything automatically.
But you can use <preConditions/> in your changeSet to check if your changeSet must be applied or not.
I'd like to use JDBC to create tables in a database agnostic way. I'm pretty sure that Liquibase has solved this problem since it can take a generic createTable XML changeSet element and convert it into a database specific SQL DDL statement.
Can someone please tell me which liquibase classes / utililities are involved in converting a generic createTable changeSet into a database specific create table SQL script?. Sample usage (ie a test case) would be great.
Please note that I do not wish to invoke the entire liquibase pipeline. In particular I do NOT want the databasechangelog table.
I'd recommend reading the liquibase unit tests.