feat: EXPOSED-43 Add support for timestamp with time zone

[joc-a]

The data type timestamp with time zone is supported by the following databases:

• H2
• Oracle
• SQLite
• SQL Server
• PostgreSQL (converted to UTC when stored, without preserving time zone info)
• MySQL 8.0.19+ (converted to UTC when stored, without preserving time zone info)

It's not supported by the following databases:

• MariaDB

Note: PostgreSQL and MySQL always store the timestamp in UTC, thereby losing the original time zone. To preserve the original time zone, store the time zone information in a separate column.

[joc-a]

@bog-walk @e5l @Tapac Still need to address the failing default test, but requesting some feedback in the meantime.

[e5l]

@Tapac, what do you think?

[joc-a]

Several tests in exposed-jodatime module were failing because they were expecting today to be in UTC time zone (as set in the init block), but were getting it in Tokyo time zone. I tried to set the time zone to UTC both before and after each test like this, but it didn't fix the failing tests.

@Before
@After
fun setTimeZone() {
    DateTimeZone.setDefault(DateTimeZone.UTC)
}

Specifying the time zone fixed it.

[Maxr1998]

@joc-a sorry for the bump. This pull request implements this feature by using OffsetDateTime, which makes sense if you need a specific timezone, but there isn't any option for this when using java.time.Instant. Of course, it's possible to convert from/to it, but this introduces unnecessary boilerplate. Are there any plans to introduce a TIMEZONE WITH TIMESTAMP column type using Instants as well (storing the timezone as UTC where supported)?
There was an attempt once in #1223, but it was superseded by this PR.

I can create a new issue for this if you think this feature is useful.

Looking at the code, this should be straightforward to implement:

JavaTimeZoneInstantColumnType

class JavaTimeZoneInstantColumnType : ColumnType(), IDateColumnType {
    override val hasTimePart: Boolean = true

    override fun sqlType(): String = currentDialect.dataTypeProvider.timestampWithTimeZoneType()

    override fun nonNullValueToString(value: Any): String = when (value) {
        is Instant -> {
            val offsetDateTime = value.atOffset(ZoneOffset.UTC)
            when (currentDialect) {
                // is SQLiteDialect -> "'${offsetDateTime.format(SQLITE_OFFSET_DATE_TIME_FORMATTER)}'"
                // is MysqlDialect -> "'${offsetDateTime.format(MYSQL_OFFSET_DATE_TIME_FORMATTER)}'"
                // is OracleDialect -> "'${offsetDateTime.format(ORACLE_OFFSET_DATE_TIME_FORMATTER)}'"
                else -> "'${offsetDateTime.format(DateTimeFormatter.ISO_OFFSET_DATE_TIME.withLocale(Locale.ROOT))}'"
            }
        }
        else -> error("Unexpected value: $value of ${value::class.qualifiedName}")
    }

    override fun valueFromDB(value: Any): Instant = when (value) {
        is Instant -> value
        is String -> {
            val offsetDateTime = when (currentDialect) {
                // is SQLiteDialect -> OffsetDateTime.parse(value, SQLITE_OFFSET_DATE_TIME_FORMATTER)
                else -> OffsetDateTime.parse(value)
            }
            offsetDateTime.toInstant()
        }
        else -> error("Unexpected value: $value of ${value::class.qualifiedName}")
    }

    override fun readObject(rs: ResultSet, index: Int): Any? = when (currentDialect) {
        is SQLiteDialect -> super.readObject(rs, index)
        else -> rs.getObject(index, OffsetDateTime::class.java)?.toInstant()
    }

    override fun notNullValueToDB(value: Any): Any = when (value) {
        is Instant -> {
            val offsetDateTime = value.atOffset(ZoneOffset.UTC)
            when (currentDialect) {
                // is SQLiteDialect -> offsetDateTime.format(SQLITE_OFFSET_DATE_TIME_FORMATTER)
                // is MysqlDialect -> offsetDateTime.format(MYSQL_OFFSET_DATE_TIME_FORMATTER)
                else -> offsetDateTime
            }
        }
        else -> error("Unexpected value: $value of ${value::class.qualifiedName}")
    }

    companion object {
        internal val INSTANCE = JavaTimeZoneInstantColumnType()
    }
}

The dialects are only commented out because the formatters are private, but they should work just as well.