Error Overrides
Published 16 November 2022
Error Overrides
When Flyway executes SQL statements it reports all warnings returned by the database. In case an error is returned Flyway displays it with all necessary details, marks the migration as failed and automatically rolls it back if possible.
The error usually looks like this:
Migration V1__Create_person_table.sql failed
--------------------------------------------
SQL State : 42001
Error Code : 42001
Message : Syntax error in SQL statement "CREATE TABLE1[*] PERSON "; expected "OR, FORCE, VIEW, ...
Location : V1__Create_person_table.sql (/flyway-tutorial/V1__Create_person_table.sql)
Line : 1
Statement : create table1 PERSON
This default behavior is great for the vast majority of the cases.
There are however situations where you may want to
- treat an error as a warning as you know your migration will handle it correctly later
- treat a warning as an error as you prefer to fail fast to be able to fix the problem sooner
- perform an additional action when a specific error or warning is being emitted by the database
Flyway Teams Edition give you a way to achieve all these scenarios using Error Overrides.
Configuration
One or more Errors Overrides can be configured using the errorOverrides
setting which accepts multiple error override definitions in the following form: STATE:12345:W
.
This is a 5 character SQL state, a colon, the SQL error code, a colon and finally the desired behavior that should override the initial one. The following behaviors are accepted:
D
to force a debug messageD-
to force a debug message, but do not show the original sql state and error codeI
to force an info messageI-
to force an info message, but do not show the original sql state and error codeW
to force a warningW-
to force a warning, but do not show the original sql state and error codeE
to force an errorE-
to force an error, but do not show the original sql state and error code
If no matching Error Overrides are configured Flyway falls back to its default behavior.
Examples
Here are some examples on how to use this feature.
Example 1: Throw an error when Oracle stored procedure compilation fails
By default when an Oracle stored procedure compilation fails, the driver simply returns a warning which is being output by Flyway as
DB: Warning: execution completed with warning (SQL State: 99999 - Error Code: 17110)
To force Oracle stored procedure compilation issues to produce errors instead of warnings, all one needs to do is add the following to Flyway's configuration:
flyway.errorOverrides=99999:17110:E
All Oracle stored procedure compilation failures will then result in an immediate error.
Example 2: Display SQL Server PRINT messages as simple info messages
By default when a SQL Server PRINT
statement executes, the message is returned as a warning to the client. This
means that the following statements:
PRINT 'Starting ...';
PRINT 'Done.';
produce the following output by default:
WARNING: DB: Starting ... (SQL State: S0001 - Error Code: 0)
WARNING: DB: Done. (SQL State: S0001 - Error Code: 0)
To force these PRINT
statements to produce simple info messages (with no SQL State and Error Code details) instead
of warnings, all one needs to do is add the following to Flyway's configuration:
flyway.errorOverrides=S0001:0:I-
With that setting in place the output then simply becomes info messages with no SQL State and Error Code details:
Starting ...
Done.
Advanced programmatic configuration
As an alternative to the simple declarative syntax presented above, you can also fully customize the behavior of Flyway
following the execution of a statement by implementing a Java-based callback which listens
to the afterEachMigrateStatement
, afterEachMigrateStatementError
, afterEachUndoStatement
and
afterEachUndoStatementError
events.
Tutorial
Click here to see a tutorial on using error overrides.