expression: fix decimal of function FROM_UNIXTIME (#14936) (#15270)

pingcap · Mar 12, 2020 · bf82a71 · bf82a71
1 parent 051a873
commit bf82a71
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Showing 3 changed files with 44 additions and 34 deletions.
diff --git a/expression/builtin_time.go b/expression/builtin_time.go
@@ -1573,7 +1573,6 @@ func (c *fromUnixTimeFunctionClass) getFunction(ctx sessionctx.Context, args []E
 		argTps = append(argTps, types.ETString)
 	}
 
-	_, isArg0Con := args[0].(*Constant)
 	isArg0Str := args[0].GetType().EvalType() == types.ETString
 	bf := newBaseBuiltinFuncWithTp(ctx, args, retTp, argTps...)
 
@@ -1583,19 +1582,10 @@ func (c *fromUnixTimeFunctionClass) getFunction(ctx sessionctx.Context, args []E
 	}
 
 	// Calculate the time fsp.
-	switch {
-	case isArg0Str:
-		bf.tp.Decimal = int(types.MaxFsp)
-	case isArg0Con:
-		arg0, arg0IsNull, err0 := args[0].EvalDecimal(ctx, chunk.Row{})
-		if err0 != nil {
-			return nil, err0
-		}
-
-		bf.tp.Decimal = int(types.MaxFsp)
-		if !arg0IsNull {
-			fsp := int(arg0.GetDigitsFrac())
-			bf.tp.Decimal = mathutil.Min(fsp, int(types.MaxFsp))
+	bf.tp.Decimal = int(types.MaxFsp)
+	if !isArg0Str {
+		if args[0].GetType().Decimal != types.UnspecifiedLength {
+			bf.tp.Decimal = mathutil.Min(bf.tp.Decimal, args[0].GetType().Decimal)
 		}
 	}
 
@@ -1638,14 +1628,9 @@ func evalFromUnixTime(ctx sessionctx.Context, fsp int, row chunk.Row, arg Expres
 	if err != nil && !terror.ErrorEqual(err, types.ErrTruncated) {
 		return res, true, err
 	}
-	fracDigitsNumber := int(unixTimeStamp.GetDigitsFrac())
 	if fsp < 0 {
 		fsp = types.MaxFsp
 	}
-	fsp = mathutil.Max(fracDigitsNumber, fsp)
-	if fsp > types.MaxFsp {
-		fsp = types.MaxFsp
-	}
 
 	sc := ctx.GetSessionVars().StmtCtx
 	tmp := time.Unix(integralPart, fractionalPart).In(sc.TimeZone)

diff --git a/expression/builtin_time_test.go b/expression/builtin_time_test.go
@@ -1150,16 +1150,16 @@ func (s *testEvaluatorSuite) TestFromUnixTime(c *C) {
 		fractionalPart int64
 		decimal        float64
 		format         string
-		ansLen         int
+		expect         string
 	}{
-		{false, 1451606400, 0, 0, "", 19},
-		{true, 1451606400, 123456000, 1451606400.123456, "", 26},
-		{true, 1451606400, 999999000, 1451606400.999999, "", 26},
-		{true, 1451606400, 999999900, 1451606400.9999999, "", 19},
-		{false, 1451606400, 0, 0, `%Y %D %M %h:%i:%s %x`, 19},
-		{true, 1451606400, 123456000, 1451606400.123456, `%Y %D %M %h:%i:%s %x`, 26},
-		{true, 1451606400, 999999000, 1451606400.999999, `%Y %D %M %h:%i:%s %x`, 26},
-		{true, 1451606400, 999999900, 1451606400.9999999, `%Y %D %M %h:%i:%s %x`, 19},
+		{false, 1451606400, 0, 0, "", "2016-01-01 08:00:00"},
+		{true, 1451606400, 123456000, 1451606400.123456, "", "2016-01-01 08:00:00.123456"},
+		{true, 1451606400, 999999000, 1451606400.999999, "", "2016-01-01 08:00:00.999999"},
+		{true, 1451606400, 999999900, 1451606400.9999999, "", "2016-01-01 08:00:01.000000"},
+		{false, 1451606400, 0, 0, `%Y %D %M %h:%i:%s %x`, "2016-01-01 08:00:00"},
+		{true, 1451606400, 123456000, 1451606400.123456, `%Y %D %M %h:%i:%s %x`, "2016-01-01 08:00:00.123456"},
+		{true, 1451606400, 999999000, 1451606400.999999, `%Y %D %M %h:%i:%s %x`, "2016-01-01 08:00:00.999999"},
+		{true, 1451606400, 999999900, 1451606400.9999999, `%Y %D %M %h:%i:%s %x`, "2016-01-01 08:00:01.000000"},
 	}
 	sc := s.ctx.GetSessionVars().StmtCtx
 	originTZ := sc.TimeZone
@@ -1176,23 +1176,32 @@ func (s *testEvaluatorSuite) TestFromUnixTime(c *C) {
 			timestamp.SetFloat64(t.decimal)
 		}
 		// result of from_unixtime() is dependent on specific time zone.
-		unixTime := time.Unix(t.integralPart, t.fractionalPart).Round(time.Microsecond).String()[:t.ansLen]
 		if len(t.format) == 0 {
-			f, err := fc.getFunction(s.ctx, s.datumsToConstants([]types.Datum{timestamp}))
+			constants := s.datumsToConstants([]types.Datum{timestamp})
+			if !t.isDecimal {
+				constants[0].GetType().Decimal = 0
+			}
+
+			f, err := fc.getFunction(s.ctx, constants)
 			c.Assert(err, IsNil)
+
 			v, err := evalBuiltinFunc(f, chunk.Row{})
 			c.Assert(err, IsNil)
 			ans := v.GetMysqlTime()
-			c.Assert(ans.String(), Equals, unixTime)
+			c.Assert(ans.String(), Equals, t.expect, Commentf("%+v", t))
 		} else {
 			format := types.NewStringDatum(t.format)
-			f, err := fc.getFunction(s.ctx, s.datumsToConstants([]types.Datum{timestamp, format}))
+			constants := s.datumsToConstants([]types.Datum{timestamp, format})
+			if !t.isDecimal {
+				constants[0].GetType().Decimal = 0
+			}
+			f, err := fc.getFunction(s.ctx, constants)
 			c.Assert(err, IsNil)
 			v, err := evalBuiltinFunc(f, chunk.Row{})
 			c.Assert(err, IsNil)
-			result, err := builtinDateFormat(s.ctx, []types.Datum{types.NewStringDatum(unixTime), format})
+			result, err := builtinDateFormat(s.ctx, []types.Datum{types.NewStringDatum(t.expect), format})
 			c.Assert(err, IsNil)
-			c.Assert(v.GetString(), Equals, result.GetString())
+			c.Assert(v.GetString(), Equals, result.GetString(), Commentf("%+v", t))
 		}
 	}
 

diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -2474,6 +2474,14 @@ func (s *testIntegrationSuite) TestBuiltin(c *C) {
 	result = tk.MustQuery("select from_unixtime(1451606400)")
 	unixTime := time.Unix(1451606400, 0).String()[:19]
 	result.Check(testkit.Rows(unixTime))
+	result = tk.MustQuery("select from_unixtime(14516064000/10)")
+	result.Check(testkit.Rows("2016-01-01 08:00:00.0000"))
+	result = tk.MustQuery("select from_unixtime('14516064000'/10)")
+	result.Check(testkit.Rows("2016-01-01 08:00:00.000000"))
+	result = tk.MustQuery("select from_unixtime(cast(1451606400 as DECIMAL))")
+	result.Check(testkit.Rows("2016-01-01 08:00:00"))
+	result = tk.MustQuery("select from_unixtime(cast(1451606400 as DECIMAL(65,1)))")
+	result.Check(testkit.Rows("2016-01-01 08:00:00.0"))
 	result = tk.MustQuery("select from_unixtime(1451606400.123456)")
 	unixTime = time.Unix(1451606400, 123456000).String()[:26]
 	result.Check(testkit.Rows(unixTime))
@@ -2485,6 +2493,14 @@ func (s *testIntegrationSuite) TestBuiltin(c *C) {
 	result.Check(testkit.Rows(unixTime))
 	result = tk.MustQuery("select from_unixtime(1511247196661)")
 	result.Check(testkit.Rows("<nil>"))
+	result = tk.MustQuery("select from_unixtime('1451606400.123');")
+	result.Check(testkit.Rows("2016-01-01 08:00:00.123000"))
+
+	tk.MustExec("drop table if exists t;")
+	tk.MustExec("create table t(a int);")
+	tk.MustExec("insert into t value(1451606400);")
+	result = tk.MustQuery("select from_unixtime(a) from t;")
+	result.Check(testkit.Rows("2016-01-01 08:00:00"))
 
 	// test strcmp
 	result = tk.MustQuery("select strcmp('abc', 'def')")