[fix](nereids)fold constant rule can't fold from_unixtime when its 1st param is decimalv3 literal

Author: starocean999

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/expressions/functions/executable/DateTimeExtractAndTransform.java

@@ -541,6 +541,11 @@ public static Expression fromUnixTime(DecimalLiteral second) {
         return fromUnixTime(second, new VarcharLiteral("%Y-%m-%d %H:%i:%s.%f"));
     }
 
+    @ExecFunction(name = "from_unixtime")
+    public static Expression fromUnixTime(DecimalV3Literal second) {
+        return fromUnixTime(second, new VarcharLiteral("%Y-%m-%d %H:%i:%s.%f"));
+    }
+
     /**
      * date transformation function: from_unixtime
      */
@@ -591,6 +596,32 @@ public static Expression fromUnixTime(DecimalLiteral second, StringLikeLiteral f
         return dateFormat(datetime, format);
     }
 
+    /**
+     * date transformation function: from_unixtime
+     */
+    @ExecFunction(name = "from_unixtime")
+    public static Expression fromUnixTime(DecimalV3Literal second, StringLikeLiteral format) {
+        format = (StringLikeLiteral) SupportJavaDateFormatter.translateJavaFormatter(format);
+
+        if (second.getValue().signum() < 0) {
+            throw new AnalysisException("Operation from_unixtime of " + second.getValue() + " out of range");
+        }
+
+        ZonedDateTime dateTime = LocalDateTime.of(1970, 1, 1, 0, 0, 0)
+                .plusSeconds(second.getValue().longValue())
+                .atZone(ZoneId.of("UTC+0"))
+                .toOffsetDateTime()
+                .atZoneSameInstant(DateUtils.getTimeZone());
+        DateTimeV2Literal datetime = new DateTimeV2Literal(DateTimeV2Type.of(6), dateTime.getYear(),
+                dateTime.getMonthValue(),
+                dateTime.getDayOfMonth(), dateTime.getHour(), dateTime.getMinute(), dateTime.getSecond(),
+                dateTime.getNano() / 1000);
+        if (datetime.checkRange()) {
+            throw new AnalysisException("Operation from_unixtime of " + second.getValue() + " out of range");
+        }
+        return dateFormat(datetime, format);
+    }
+
     /**
      * date transformation function: unix_timestamp
      */

fe/fe-core/src/main/java/org/apache/doris/nereids/util/DateUtils.java

@@ -219,9 +219,12 @@ public static DateTimeFormatter dateTimeFormatterChecklength(String pattern, Dat
                         builder.appendValueReduced(ChronoField.YEAR, 2, 2, 1970);
                         length += 2;
                         break;
+                    case 'f':
+                        builder.appendValue(ChronoField.MICRO_OF_SECOND, 6);
+                        length += 6;
+                        break;
                     // TODO(Gabriel): support microseconds in date literal
                     case 'D': // %D Day of the month with English suffix (0th, 1st, 2nd, 3rd, …)
-                    case 'f': // %f Microseconds (000000..999999)
                     case 'U': // %U Week (00..53), where Sunday is the first day of the week
                     case 'u': // %u Week (00..53), where Monday is the first day of the week
                     case 'w': // %w Day of the week (0=Sunday..6=Saturday)

fe/fe-core/src/test/java/org/apache/doris/nereids/rules/expression/FoldConstantTest.java

@@ -107,6 +107,7 @@
 import org.apache.doris.nereids.trees.expressions.literal.DateTimeLiteral;
 import org.apache.doris.nereids.trees.expressions.literal.DateTimeV2Literal;
 import org.apache.doris.nereids.trees.expressions.literal.DateV2Literal;
+import org.apache.doris.nereids.trees.expressions.literal.DecimalLiteral;
 import org.apache.doris.nereids.trees.expressions.literal.DecimalV3Literal;
 import org.apache.doris.nereids.trees.expressions.literal.DoubleLiteral;
 import org.apache.doris.nereids.trees.expressions.literal.FloatLiteral;
@@ -473,6 +474,14 @@ void testFoldString() {
         rewritten = executor.rewrite(f, context);
         Assertions.assertEquals(new VarcharLiteral("73 11 30"), rewritten);
 
+        f = new FromUnixtime(DecimalLiteral.of(new BigDecimal("1761548288.000000")));
+        rewritten = executor.rewrite(f, context);
+        Assertions.assertEquals(new VarcharLiteral("2025-10-27 14:58:08.000000"), rewritten);
+
+        f = new FromUnixtime(DecimalV3Literal.of(new BigDecimal("1761548288.000000")));
+        rewritten = executor.rewrite(f, context);
+        Assertions.assertEquals(new VarcharLiteral("2025-10-27 14:58:08.000000"), rewritten);
+
         UnixTimestamp ut = new UnixTimestamp(StringLiteral.of("2021-11-11"), StringLiteral.of("%Y-%m-%d"));
         rewritten = executor.rewrite(ut, context);
         Assertions.assertEquals(new DecimalV3Literal(DecimalV3Type.createDecimalV3TypeNoCheck(18, 6),