expression: from_unixtime accept 64-bit integers (#22616)

close #22206

expression/builtin_time.go

@@ -1694,15 +1694,17 @@ func (c *fromUnixTimeFunctionClass) getFunction(ctx sessionctx.Context, args []E
 }
 
 func evalFromUnixTime(ctx sessionctx.Context, fsp int, unixTimeStamp *types.MyDecimal) (res types.Time, isNull bool, err error) {
-	// 0 <= unixTimeStamp <= INT32_MAX
+	// 0 <= unixTimeStamp <= 32536771199.999999
 	if unixTimeStamp.IsNegative() {
 		return res, true, nil
 	}
 	integralPart, err := unixTimeStamp.ToInt()
 	if err != nil && !terror.ErrorEqual(err, types.ErrTruncated) {
 		return res, true, err
 	}
-	if integralPart > int64(math.MaxInt32) {
+	// The max integralPart should not be larger than 32536771199.
+	// Refer to https://dev.mysql.com/doc/relnotes/mysql/8.0/en/news-8-0-28.html
+	if integralPart > 32536771199 {
 		return res, true, nil
 	}
 	// Split the integral part and fractional part of a decimal timestamp.

expression/integration_test.go

@@ -7028,3 +7028,21 @@ func TestIssue29708(t *testing.T) {
 		{"b"},
 	})
 }
+
+func TestIssue22206(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+
+	tz := tk.Session().GetSessionVars().StmtCtx.TimeZone
+	result := tk.MustQuery("select from_unixtime(32536771199.999999)")
+	unixTime := time.Unix(32536771199, 999999000).In(tz).String()[:26]
+	result.Check(testkit.Rows(unixTime))
+	result = tk.MustQuery("select from_unixtime('32536771200.000000')")
+	result.Check(testkit.Rows("<nil>"))
+	result = tk.MustQuery("select from_unixtime(5000000000);")
+	unixTime = time.Unix(5000000000, 0).In(tz).String()[:19]
+	result.Check(testkit.Rows(unixTime))
+}