public List<String> build() {
    if (columnDefs.isEmpty()) {
      throw new IllegalStateException("No column has been defined");
    }
    switch (dialect.getId()) {
      case PostgreSql.ID:
        return createPostgresQuery();
      case Oracle.ID:
        return createOracleQuery();
      default:
        return createMsSqlAndH2Queries();
    }
  }
@Test
  public void update_not_nullable_column_on_mssql() {
    assertThat(createNotNullableBuilder(new MsSql()).build())
      .containsOnly("ALTER TABLE issues ALTER COLUMN name NVARCHAR (10) NOT NULL");
  }