Include column data type to SetColumnRemarksChange for MySQL support

[potados99]

Environment

Liquibase Version: 4.5.1-local-SNAPSHOT

Database Vendor & Version: MySQL 8

Operating System Type & Version: macOS 11.6

Pull Request Type

• Bug fix (non-breaking change which fixes an issue.)
• Enhancement/New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

MySQL needs column data type along with a column remark change. Even if the columnDataType is not actually changed, the type is required for MySQL to modify a remark on the column. So I included it in SetColumnRemarksChange.

Steps To Reproduce

To reproduce a problem this PR is trying to fix:

1. Prepare two empty MySQL databases(comparison, reference respectively)
2. Create a table tester, with columns INT(10) id as pk and VARCHAR(10) name, on both databases.
3. Add a comment to the name column on the reference database.
4. Create a diffChangeLog in SQL.

These steps will make a NullPointerException:

Caused by: java.lang.NullPointerException
        at liquibase.sqlgenerator.core.SetColumnRemarksGenerator.generateSql(SetColumnRemarksGenerator.java:50)
        at liquibase.sqlgenerator.core.SetColumnRemarksGenerator.generateSql(SetColumnRemarksGenerator.java:15)
        at liquibase.sqlgenerator.SqlGeneratorChain.generateSql(SqlGeneratorChain.java:30)
        at liquibase.sqlgenerator.SqlGeneratorFactory.generateSql(SqlGeneratorFactory.java:220)
        at liquibase.sqlgenerator.SqlGeneratorFactory.generateSql(SqlGeneratorFactory.java:206)
        at liquibase.serializer.core.formattedsql.FormattedSqlChangeLogSerializer.serialize(FormattedSqlChangeLogSerializer.java:58)
        at liquibase.serializer.core.formattedsql.FormattedSqlChangeLogSerializer.write(FormattedSqlChangeLogSerializer.java:104)
        at liquibase.diff.output.changelog.DiffToChangeLog.print(DiffToChangeLog.java:248)
        at liquibase.diff.output.changelog.DiffToChangeLog$1.run(DiffToChangeLog.java:137)
        ... 21 more

The line that throws the exception requires a column data type, which does not exist, because the data type is not actually changed.

liquibase/liquibase-core/src/main/java/liquibase/sqlgenerator/core/SetColumnRemarksGenerator.java

Line 50 in 256675b

+ DataTypeFactory.getInstance().fromDescription(statement.getColumnDataType(), database).toDatabaseDataType(database)

[molivasdat]

Hi @potados99 Thanks for creating this fix.
We will add to the list of PRs that we are processing.

A member of the Liquibase team will take a look at your contribution and may suggest:

• Changes based on guidelines for PR submission
• Additional tests (unit and/or integration) and/or Test Harness Tests
• Provide other feedback, like requesting changes.

The PR will be prioritized according to our internal development and testing capacity.

We’ll let you know when it’s ready to move to the next step or if any changes are needed.

[nvoxland]

This is a duplicate of #2188 which is already in flight.

Thanks!