[FLINK-36358][table] Fix incorrect precision retention when converting timestamps to strings
This closes #25382
diff --git a/flink-table/flink-table-common/src/main/java/org/apache/flink/table/utils/DateTimeUtils.java b/flink-table/flink-table-common/src/main/java/org/apache/flink/table/utils/DateTimeUtils.java
index 4c58201..3a71144 100644
--- a/flink-table/flink-table-common/src/main/java/org/apache/flink/table/utils/DateTimeUtils.java
+++ b/flink-table/flink-table-common/src/main/java/org/apache/flink/table/utils/DateTimeUtils.java
@@ -695,8 +695,8 @@
LocalDateTime ldt = ts.toLocalDateTime();
String fraction = pad(9, ldt.getNano());
- while (fraction.length() > precision && fraction.endsWith("0")) {
- fraction = fraction.substring(0, fraction.length() - 1);
+ if (fraction.length() > precision) {
+ fraction = fraction.substring(0, precision);
}
StringBuilder ymdhms =
diff --git a/flink-table/flink-table-planner/src/test/scala/org/apache/flink/table/planner/expressions/TemporalTypesTest.scala b/flink-table/flink-table-planner/src/test/scala/org/apache/flink/table/planner/expressions/TemporalTypesTest.scala
index 6819dab..5011495 100644
--- a/flink-table/flink-table-planner/src/test/scala/org/apache/flink/table/planner/expressions/TemporalTypesTest.scala
+++ b/flink-table/flink-table-planner/src/test/scala/org/apache/flink/table/planner/expressions/TemporalTypesTest.scala
@@ -986,6 +986,13 @@
"2000-02-02 00:59:59.123")
testSqlApi("TO_TIMESTAMP('1234567', 'SSSSSSS')", "1970-01-01 00:00:00.123")
+
+ testSqlApi(
+ "TO_TIMESTAMP('2017-09-15 00:00:00.12345', 'yyyy-MM-dd HH:mm:ss.SSS')",
+ "2017-09-15 00:00:00.123")
+ testSqlApi(
+ "CAST(TO_TIMESTAMP('2017-09-15 00:00:00.12345', 'yyyy-MM-dd HH:mm:ss.SSS') AS STRING)",
+ "2017-09-15 00:00:00.123")
}
@Test
