'afterColumn' and 'position' not working in Firebird and Oracle databases

Environment

Liquibase Version: 3.8.5 - 4.1

Liquibase Integration & Version: gradle

Liquibase Extension(s) & Version:

Database Vendor & Version: firebird 2.5, oracle

Operating System Type & Version: win 10 java 8

Description

The ‘addColumn’ tag supports ‘afterColumn’ and ‘position’, but these tags are ignored in the SQL generation in Firebird and Oracle ( https://docs.liquibase.com/concepts/advanced/column.html ). Therefore it is not possible to insert a column at a specific position in Firebird or after a column in Oracle.

There is also no documentation on which dbms supports ‘afterColumn’ or ‘position’.

Steps To Reproduce

JUnit Test:

 @Test
  void testLiquibaseOrderBug() throws IOException {
    DatabaseChangeLog log = new DatabaseChangeLog();
    ChangeSet set = new ChangeSet("Test", "test", Boolean.FALSE, Boolean.FALSE, null, "context",
                                  "firebird", log);
    AddColumnChange addcol = new AddColumnChange();
    addcol.setTableName("MI6");
    AddColumnConfig addColumnConfig = new AddColumnConfig();
    addColumnConfig.setType("int");
    addColumnConfig.setValueNumeric(0);
    addColumnConfig.setName("James");
    addColumnConfig.setPosition(2);
    addcol.addColumn(addColumnConfig);
    set.addChange(addcol);

    String[] changesets = getXmlChangelogAsArray(set);
    assertEquals("<column name=\"James\" position=\"2\" type=\"int\" valueNumeric=\"0\"/>",changesets[4].trim());

    assertEquals("ALTER TABLE MI6 ADD James INT POSITION 2;", getLiquiSql("firebird", set));
  }

  @Test
  void testLiquibaseAfterBug() throws IOException {
    DatabaseChangeLog log = new DatabaseChangeLog();
    ChangeSet set = new ChangeSet("Test", "test", Boolean.FALSE, Boolean.FALSE, null, "context",
                                  "oracle", log);
    AddColumnChange addcol = new AddColumnChange();
    addcol.setTableName("MI6");
    AddColumnConfig addColumnConfig = new AddColumnConfig();
    addColumnConfig.setType("int");
    addColumnConfig.setValueNumeric(0);
    addColumnConfig.setName("James");
    addColumnConfig.setAfterColumn("Bond");
    addcol.addColumn(addColumnConfig);
    set.addChange(addcol);

    String[] changesets = getXmlChangelogAsArray(set);
    assertEquals("<column afterColumn=\"Bond\" name=\"James\" type=\"int\" valueNumeric=\"0\"/>",changesets[4].trim());

    assertEquals("ALTER TABLE MI6 ADD James INTEGER AFTER Bond;", getLiquiSql("oracle", set));
  }

  private String[] getXmlChangelogAsArray(ChangeSet set) throws IOException {
    List<ChangeLogChild> changes = new ArrayList<>();
    changes.add(set);
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    ChangeLogSerializer serializer = new XMLChangeLogSerializer();
    serializer.write(changes, stream);
    String[] changesets = new String(stream.toByteArray()).replaceAll("\r", "")
      .split("\n");
    return changesets;
  }
  
  private String getLiquiSql(String dbms, ChangeSet set) throws IOException {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    ChangeLogSerializer serializer = new FormattedSqlChangeLogSerializer();
    set.setFilePath("export."+dbms+".sql");
    List<ChangeLogChild> changes = new ArrayList<>();
    changes.add(set);
    serializer.write(changes, stream);
    return new String(stream.toByteArray()).split("\n")[3];
  }

Actual Behavior

Positions and afterColumn tags are ignored. An afterTable tag in Oracle leads to following sql: ALTER TABLE MI6 ADD James INTEGER A position tag in Firebird leads to following sql: ALTER TABLE MI6 ADD James INT

Expected/Desired Behavior

<changeSet author="test" context="context" dbms="firebird" id="Test" objectQuotingStrategy="LEGACY"> <addColumn tableName="MI6"> <column name="James" position="2" type="int" valueNumeric="0"/> </addColumn> </changeSet>

should create in Firebird something like

ALTER TABLE MI6 ADD James INT POSITION 2

and

<changeSet author="test" context="context" dbms="firebird,oracle,mssql" id="Test" objectQuotingStrategy="LEGACY"> <addColumn tableName="MI6"> <column afterColumn="Bond" name="James" type="int" valueNumeric="0"/> </addColumn> </changeSet>

should create in Oracle something like

ALTER TABLE MI6 ADD James INTEGER AFTER Bond

[theovanessen]

@chenmeister Thanks for the replay. I learned something again today.

[molivasdat]

Hi @kuhjunge Thanks for doing the research. I found that the same alter table mi6 alter james position 2 works as the way you describe on Firebird 3.0 too.

but that means <changeSet author="test" context="context" dbms="firebird" id="Test" objectQuotingStrategy="LEGACY"> <addColumn tableName="MI6"> <column name="James" position="2" type="int" valueNumeric="0"/> </addColumn> </changeSet>

is two sql statements ALTER TABLE MI6 ADD James INT; and ALTER TABLE MI6 alter James position 2;

which means 2 alter table statements are needed for the single changeset on Firebird. The first adds the column and the second moves it.

Where MYSQL is only one statement. ALTER TABLE MI6 ADD James INT after bond; Is that what you see? If so, we need to rethink the PR that was used to fix this issue.