From b33e26501e0218279417bfd27e0e5b160db2c9aa Mon Sep 17 00:00:00 2001
From: "Andrey.Tarashevskiy" <fantocci@gmail.com>
Date: Thu, 1 Jul 2021 01:56:32 +0300
Subject: [PATCH] LocalDateTime regression #1028

---
 .../sql/java-time/JavaDateColumnType.kt       |  6 ++--
 .../org/jetbrains/exposed/JavaTimeTests.kt    | 31 ++++++++++++++++---
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/exposed-java-time/src/main/kotlin/org/jetbrains/exposed/sql/java-time/JavaDateColumnType.kt b/exposed-java-time/src/main/kotlin/org/jetbrains/exposed/sql/java-time/JavaDateColumnType.kt
index 01ee21f3f3..f12761883f 100644
--- a/exposed-java-time/src/main/kotlin/org/jetbrains/exposed/sql/java-time/JavaDateColumnType.kt
+++ b/exposed-java-time/src/main/kotlin/org/jetbrains/exposed/sql/java-time/JavaDateColumnType.kt
@@ -115,8 +115,10 @@ class JavaLocalDateTimeColumnType : ColumnType(), IDateColumnType {
     override fun notNullValueToDB(value: Any): Any = when {
         value is LocalDateTime && currentDialect is SQLiteDialect ->
             SQLITE_AND_ORACLE_DATE_TIME_STRING_FORMATTER.format(value.atZone(ZoneId.systemDefault()))
-        value is LocalDateTime ->
-            java.sql.Timestamp(value.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli())
+        value is LocalDateTime -> {
+            val instant = value.atZone(ZoneId.systemDefault()).toInstant()
+            java.sql.Timestamp(instant.toEpochMilli()).apply { nanos = instant.nano }
+        }
         else -> value
     }
 
diff --git a/exposed-java-time/src/test/kotlin/org/jetbrains/exposed/JavaTimeTests.kt b/exposed-java-time/src/test/kotlin/org/jetbrains/exposed/JavaTimeTests.kt
index 54574ce7c8..7a447c530f 100644
--- a/exposed-java-time/src/test/kotlin/org/jetbrains/exposed/JavaTimeTests.kt
+++ b/exposed-java-time/src/test/kotlin/org/jetbrains/exposed/JavaTimeTests.kt
@@ -7,7 +7,7 @@ import org.jetbrains.exposed.sql.tests.DatabaseTestsBase
 import org.jetbrains.exposed.sql.tests.TestDB
 import org.jetbrains.exposed.sql.tests.currentDialectTest
 import org.jetbrains.exposed.sql.tests.shared.assertEquals
-import org.jetbrains.exposed.sql.vendors.MysqlDialect
+import org.jetbrains.exposed.sql.vendors.*
 import org.junit.Test
 import java.time.*
 import java.time.temporal.Temporal
@@ -71,6 +71,22 @@ open class JavaTimeBaseTest : DatabaseTestsBase() {
             }
         }
     }
+
+    @Test
+    fun `test storing LocalDateTime with nanos`() {
+        val TestDate = object : IntIdTable("TestLocalDateTime") {
+            val time = datetime("time")
+        }
+        withTables(TestDate) {
+            val dateTimeWithNanos = LocalDateTime.now().withNano(123)
+            TestDate.insert {
+                it[time] = dateTimeWithNanos
+            }
+
+            val dateTimeFromDB = TestDate.selectAll().single()[TestDate.time]
+            assertEqualDateTime(dateTimeWithNanos, dateTimeFromDB)
+        }
+    }
 }
 
 fun <T : Temporal> assertEqualDateTime(d1: T?, d2: T?) {
@@ -87,14 +103,21 @@ fun <T : Temporal> assertEqualDateTime(d1: T?, d2: T?) {
         d1 is LocalTime && d2 is LocalTime && d2.nano == 0 -> assertEquals<LocalTime>(d1.withNano(0), d2, "Failed on ${currentDialectTest.name}")
         d1 is LocalTime && d2 is LocalTime -> assertEquals<LocalTime>(d1, d2, "Failed on ${currentDialectTest.name}")
         d1 is LocalDateTime && d2 is LocalDateTime -> {
-            val d1Millis = Instant.from(d1.atZone(ZoneId.systemDefault())).toEpochMilli()
-            val d2Millis = Instant.from(d2.atZone(ZoneId.systemDefault())).toEpochMilli()
-            assertEquals(d1Millis, d2Millis, "Failed on ${currentDialectTest.name}")
+            val d1Nanos = currentDialectTest.extractNanos(d1)
+            val d2Nanos = currentDialectTest.extractNanos(d1)
+            assertEquals(d1.second + d1Nanos, d2.second + d2Nanos, "Failed on ${currentDialectTest.name}")
         }
         else -> assertEquals(d1, d2, "Failed on ${currentDialectTest.name}")
     }
 }
 
+private fun DatabaseDialect.extractNanos(dt: LocalDateTime) = when (this) {
+    is MysqlDialect -> dt.nano.toString().take(6).toInt() // 1000000 ns
+    is SQLiteDialect -> 0
+    is PostgreSQLDialect -> dt.nano.toString().take(1).toInt() // 1 ms
+    else -> dt.nano
+}
+
 fun equalDateTime(d1: Temporal?, d2: Temporal?) = try {
     assertEqualDateTime(d1, d2)
     true