show import: fix show import might read data from prev line

executor/importer/BUILD.bazel

@@ -83,7 +83,7 @@ go_test(
     embed = [":importer"],
     flaky = True,
     race = "on",
-    shard_count = 10,
+    shard_count = 11,
     deps = [
         "//br/pkg/errors",
         "//br/pkg/lightning/config",

executor/importer/job.go

@@ -258,24 +258,42 @@ func FailJob(ctx context.Context, conn sqlexec.SQLExecutor, jobID int64, errorMs
 }
 
 func convert2JobInfo(row chunk.Row) (*JobInfo, error) {
+	// start_time, end_time, summary, error_message can be NULL, need to use row.IsNull() to check.
+	startTime, endTime := types.ZeroTime, types.ZeroTime
+	if !row.IsNull(2) {
+		startTime = row.GetTime(2)
+	}
+	if !row.IsNull(3) {
+		endTime = row.GetTime(3)
+	}
+
 	parameters := ImportParameters{}
 	parametersStr := row.GetString(8)
 	if err := json.Unmarshal([]byte(parametersStr), &parameters); err != nil {
 		return nil, errors.Trace(err)
 	}
+
 	var summary *JobSummary
-	summaryStr := row.GetString(12)
+	var summaryStr string
+	if !row.IsNull(12) {
+		summaryStr = row.GetString(12)
+	}
 	if len(summaryStr) > 0 {
 		summary = &JobSummary{}
 		if err := json.Unmarshal([]byte(summaryStr), summary); err != nil {
 			return nil, errors.Trace(err)
 		}
 	}
+
+	var errMsg string
+	if !row.IsNull(13) {
+		errMsg = row.GetString(13)
+	}
 	return &JobInfo{
 		ID:             row.GetInt64(0),
 		CreateTime:     row.GetTime(1),
-		StartTime:      row.GetTime(2),
-		EndTime:        row.GetTime(3),
+		StartTime:      startTime,
+		EndTime:        endTime,
 		TableSchema:    row.GetString(4),
 		TableName:      row.GetString(5),
 		TableID:        row.GetInt64(6),
@@ -285,7 +303,7 @@ func convert2JobInfo(row chunk.Row) (*JobInfo, error) {
 		Status:         row.GetString(10),
 		Step:           row.GetString(11),
 		Summary:        summary,
-		ErrorMessage:   row.GetString(13),
+		ErrorMessage:   errMsg,
 	}, nil
 }
 

executor/importer/job_test.go

@@ -279,3 +279,56 @@ func TestJobInfo_CanCancel(t *testing.T) {
 		require.Equal(t, c.canCancel, jobInfo.CanCancel(), c.status)
 	}
 }
+
+func TestGetJobInfoNullField(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	ctx := context.Background()
+	conn := tk.Session().(sqlexec.SQLExecutor)
+	jobInfo := &importer.JobInfo{
+		TableSchema: "test",
+		TableName:   "t",
+		TableID:     1,
+		CreatedBy:   "user-for-test@%",
+		Parameters: importer.ImportParameters{
+			ColumnsAndVars: "(a, b, c)",
+			SetClause:      "d = 1",
+			Format:         importer.DataFormatCSV,
+			Options: map[string]interface{}{
+				"skip_rows": float64(1), // json unmarshal will convert number to float64
+				"detached":  nil,
+			},
+		},
+		SourceFileSize: 123,
+		Status:         "pending",
+	}
+	// create jobs
+	jobID1, err := importer.CreateJob(ctx, conn, jobInfo.TableSchema, jobInfo.TableName, jobInfo.TableID,
+		jobInfo.CreatedBy, &jobInfo.Parameters, jobInfo.SourceFileSize)
+	require.NoError(t, err)
+	require.NoError(t, importer.StartJob(ctx, conn, jobID1))
+	require.NoError(t, importer.FailJob(ctx, conn, jobID1, "failed"))
+	jobID2, err := importer.CreateJob(ctx, conn, jobInfo.TableSchema, jobInfo.TableName, jobInfo.TableID,
+		jobInfo.CreatedBy, &jobInfo.Parameters, jobInfo.SourceFileSize)
+	require.NoError(t, err)
+	gotJobInfos, err := importer.GetAllViewableJobs(ctx, conn, "", true)
+	require.NoError(t, err)
+	require.Len(t, gotJobInfos, 2)
+	// result should be in order, jobID1, jobID2
+	jobInfo.ID = jobID1
+	jobInfo.Status = "failed"
+	jobInfo.Step = importer.JobStepImporting
+	jobInfo.ErrorMessage = "failed"
+	jobInfoEqual(t, jobInfo, gotJobInfos[0])
+	require.False(t, gotJobInfos[0].StartTime.IsZero())
+	require.False(t, gotJobInfos[0].EndTime.IsZero())
+	jobInfo.ID = jobID2
+	jobInfo.Status = "pending"
+	jobInfo.Step = ""
+	// err msg of jobID2 should be empty
+	jobInfo.ErrorMessage = ""
+	jobInfoEqual(t, jobInfo, gotJobInfos[1])
+	// start/end time of jobID2 should be zero
+	require.True(t, gotJobInfos[1].StartTime.IsZero())
+	require.True(t, gotJobInfos[1].EndTime.IsZero())
+}