documentation/Reference/Commands/Diff.md
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Compares two comparison sources and returns a summary of the differences. A comparison source can either be a database
environment, build environment, a schema model folder, a snapshot or empty type.
Additionally, the diff command will generate and store the differences between the two comparison sources in the artifact
that can subsequently be used with the generate, model and diffText commands.
For more information see Database comparisons
Here the environment will contain a database with a single view and table, view1 and table1 respectively. The
schemaModel will have the same table1 with modifications, and an additional table2 table.
The diff command can then be used to compare the dev environment to the schema model which would list out the object
level differences between them.
In this example a snapshot has to be generated prior to performing diff. The snapshot is a JSON file that could be
generated by performing the snapshot command against an environment/schemaModel. In this scenario the snapshot is of
an environment which contains two tables, Table_1 and Table_2.
The diff command will print the above two tables as differences.
To perform this scenario of diff as a prerequisite the build environment has to be configured to use
the clean provisioner in order to reprovision the environment upon setting the rebuild flag to true. The migration
directory contains four migrations, V1__first.sql, V2__table1.sql,V3__view1.sql and V4__table2.sql with the
target environment not being migrated to these versions. The build environment contains a table table_3 in the schema tested in this example.
As a result of this operation the build environment would be cleaned and all migration scripts including the build
version 3 specified would be run and then be compared against the target environment which contains only the schema and schema_history table. The
differences listed out would contain only the objects created from the migrations scripts specified as ADD type changes since the build environment is rebuild.
The migration directory contains four migrations, V1__first.sql, V2__table1.sql,V3__view1.sql and V4__table2.sql with the target
environment not being migrated to these versions. The build environment contains a table table_3 in the schema tested in this example.
As a result of this operation only versions 2 and 4 will be applied to the build environment, which will
then be compared against the target environment which contains only the schema and schema_history table. The differences listed out would
contain only the objects created from the migrations scripts run as ADD type changes since the build environment is rebuilt.
| Parameter | Namespace | Description |
|---|---|---|
source | diff | The source to use for the diff operation. |
target | diff | The target to use for the diff operation. |
| Parameter | Namespace | Description |
|---|---|---|
artifactFilename | diff | The output location of the diff artifact. |
buildEnvironment | diff | If source/target is migrations, this specifies the environment to use as the build environment. |
buildVersion | diff | If source/target is migrations, this specifies migration version to migrate the build environment to. |
buildCherryPick | diff | If source/target is migrations, this specifies list of migrations to migrate the build environment with. |
rebuild | diff | If source/target is migrations, forces a reprovision (rebuild) of the build environment. |
snapshotSchemas | diff | The schemas used for a snapshot comparison source/target. |
includeFlywayObjects | diff | Should the diff include flyway objects (e.g. schema history table). |
schemaModelLocation | (root) | The path to the schema model. |
schemaModelSchemas | (root) | The schemas in the schema model. |
workingDirectory | (root) | The directory to consider the current working directory. All relative paths will be considered relative to this. |
| {environment parameters} | (root) | Environment configuration for the source and/or target environments. |
Universal commandline parameters are listed here.
Settings from the following sections of the Flyway namespace can be specified in relation to database connections:
When the source or target is migrations is used, settings from the following sections of the Flyway namespace can also be set:
{
"differences": [
"differenceType": "Add",
"objectType": "Table",
"from": {
"schema": "dbo",
"name": "Table1",
},
"to": null
],
"sourcePreparationInfo": null,
"targetPreparationInfo": {
"sourceType": "migrations",
"provisioner": "clean",
"migrationState": {
"pending": 1,
"applied": 1,
"failed": 0,
"total": 1
},
"reprovisioned": true,
"targetSchemaVersion": "001",
"migrationsExecuted": 1,
}
}
This command can produce the following error codes: