expression, types: use time.Add() to calculate subtime (#32903)

close #31868
pingcap · Mar 16, 2022 · 0f343d3 · 0f343d3
1 parent 2dd0074
commit 0f343d3
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Showing 5 changed files with 19 additions and 45 deletions.
diff --git a/expression/builtin_time.go b/expression/builtin_time.go
@@ -5391,21 +5391,16 @@ func strDatetimeSubDuration(sc *stmtctx.StatementContext, d string, arg1 types.D
 		sc.AppendWarning(err)
 		return "", true, nil
 	}
-	arg1time, err := arg1.ConvertToTime(sc, uint8(types.GetFsp(arg1.String())))
+	resultTime, err := arg0.Add(sc, arg1.Neg())
 	if err != nil {
 		return "", false, err
 	}
-	tmpDuration := arg0.Sub(sc, &arg1time)
 	fsp := types.MaxFsp
-	if tmpDuration.MicroSecond() == 0 {
+	if resultTime.Microsecond() == 0 {
 		fsp = types.MinFsp
 	}
-	resultDuration, err := tmpDuration.ConvertToTime(sc, mysql.TypeDatetime)
-	if err != nil {
-		return "", false, err
-	}
-	resultDuration.SetFsp(fsp)
-	return resultDuration.String(), false, nil
+	resultTime.SetFsp(fsp)
+	return resultTime.String(), false, nil
 }
 
 // strDurationSubDuration subtracts duration from duration string, returns a string value.
@@ -6476,12 +6471,7 @@ func (b *builtinSubDatetimeAndDurationSig) evalTime(row chunk.Row) (types.Time,
 		return types.ZeroDatetime, isNull, err
 	}
 	sc := b.ctx.GetSessionVars().StmtCtx
-	arg1time, err := arg1.ConvertToTime(sc, mysql.TypeDatetime)
-	if err != nil {
-		return arg1time, true, err
-	}
-	tmpDuration := arg0.Sub(sc, &arg1time)
-	result, err := tmpDuration.ConvertToTime(sc, arg0.Type())
+	result, err := arg0.Add(sc, arg1.Neg())
 	return result, err != nil, err
 }
 
@@ -6521,12 +6511,7 @@ func (b *builtinSubDatetimeAndStringSig) evalTime(row chunk.Row) (types.Time, bo
 		}
 		return types.ZeroDatetime, true, err
 	}
-	arg1time, err := arg1.ConvertToTime(sc, mysql.TypeDatetime)
-	if err != nil {
-		return types.ZeroDatetime, true, err
-	}
-	tmpDuration := arg0.Sub(sc, &arg1time)
-	result, err := tmpDuration.ConvertToTime(sc, mysql.TypeDatetime)
+	result, err := arg0.Add(sc, arg1.Neg())
 	return result, err != nil, err
 }
 

diff --git a/expression/builtin_time_test.go b/expression/builtin_time_test.go
@@ -1036,6 +1036,8 @@ func TestSubTimeSig(t *testing.T) {
 		{"110:00:00", "1 02:00:00", "84:00:00"},
 		{"2017-01-01 01:01:01.11", "01:01:01.11111", "2016-12-31 23:59:59.998890"},
 		{"2007-12-31 23:59:59.999999", "1 1:1:1.000002", "2007-12-30 22:58:58.999997"},
+		{"1000-01-01 01:00:00.000000", "00:00:00.000001", "1000-01-01 00:59:59.999999"},
+		{"1000-01-01 01:00:00.000001", "00:00:00.000001", "1000-01-01 01:00:00"},
 		{"1", "xxcvadfgasd", ""},
 		{"xxcvadfgasd", "1", ""},
 	}

diff --git a/expression/builtin_time_vec_generated.go b/expression/builtin_time_vec_generated.go
diff --git a/expression/generator/time_vec.go b/expression/generator/time_vec.go
@@ -175,12 +175,7 @@ func (b *{{.SigName}}) vecEval{{ .Output.TypeName }}(input *chunk.Chunk, result
 		{{ else }}
 		sc := b.ctx.GetSessionVars().StmtCtx
 		arg1Duration := types.Duration{Duration: arg1, Fsp: -1}
-		arg1time, err := arg1Duration.ConvertToTime(sc, mysql.TypeDatetime)
-		if err != nil {
-			return err
-		}
-		tmpDuration := arg0.Sub(sc, &arg1time)
-		output, err := tmpDuration.ConvertToTime(sc, arg0.Type())
+		output, err := arg0.Add(sc, arg1Duration.Neg())
 		{{ end }}
 		if err != nil {
 			return err
@@ -205,12 +200,7 @@ func (b *{{.SigName}}) vecEval{{ .Output.TypeName }}(input *chunk.Chunk, result
 			}
 			return err
 		}
-		arg1time, err := arg1Duration.ConvertToTime(sc, mysql.TypeDatetime)
-		if err != nil {
-			return err
-		}
-		tmpDuration := arg0.Sub(sc, &arg1time)
-		output, err := tmpDuration.ConvertToTime(sc, mysql.TypeDatetime)
+		output, err := arg0.Add(sc, arg1Duration.Neg())
 		{{ end }}
 		if err != nil {
 			return err

diff --git a/expression/integration_serial_test.go b/expression/integration_serial_test.go
@@ -2115,6 +2115,13 @@ func TestTimeBuiltin(t *testing.T) {
 	tk.MustQuery("select subtime(cast('10:10:10' as time), cast('9:10:10' as time))").Check(testkit.Rows("01:00:00"))
 	tk.MustQuery("select subtime('10:10:10', cast('9:10:10' as time))").Check(testkit.Rows("01:00:00"))
 
+	// SUBTIME issue #31868
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a DATETIME(6))")
+	tk.MustExec(`insert into t values ("1000-01-01 01:00:00.000000"), ("1000-01-01 01:00:00.000001")`)
+	tk.MustQuery(`SELECT SUBTIME(a, '00:00:00.000001') FROM t ORDER BY a;`).Check(testkit.Rows("1000-01-01 00:59:59.999999", "1000-01-01 01:00:00.000000"))
+	tk.MustQuery(`SELECT SUBTIME(a, '10:00:00.000001') FROM t ORDER BY a;`).Check(testkit.Rows("0999-12-31 14:59:59.999999", "0999-12-31 15:00:00.000000"))
+
 	// ADDTIME & SUBTIME issue #5966
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("create table t(a datetime, b timestamp, c time, d date, e bit(1))")