[-] fix serialization of errors in db logger

[MaxaiZer]

Task errors are currently serialized inconsistently. If ExecuteSQLCommand fails during this block:

if len(paramValues) == 0 { 
  ct, e := executor.Exec(ctx, task.Command)
  pge.LogTaskExecution(context.Background(), task, errCodes[e != nil], ct.String(), "") 
  return e
}

message_data.error in the "Task execution failed" log entry (in the timetable.log table) will contain a full pgconn.PgError struct:

{"task": 1, "vxid": 1, "chain": 1, "error": {"Code": "42P02", "File": "parse_expr.c", "Hint": "", "Line": 901, "Where": "", "Detail": "", "Message": "there is no parameter $1", "Routine": "transformParamRef", "Position": 175, "Severity": "ERROR", "TableName": "", "ColumnName": "", "SchemaName": "", "DataTypeName": "", "InternalQuery": "", "ConstraintName": "", "InternalPosition": 0, "SeverityUnlocalized": "ERROR"}}

If it fails during parameter parsing:

if err = json.Unmarshal([]byte(val), &params); err != nil {
    return
}

message_data.error will contain struct with no actual error message:

{"task": 1, "vxid": 1, "chain": 1, "error": {"Type": {}, "Field": "", "Value": "string", "Offset": 9, "Struct": ""}}

And if ExecuteSQLCommand returns joined errors, message_data.error becomes empty:

{"task": 1, "vxid": 1, "chain": 1, "error": {}}

After fix examples:

• single postgres error:

{"task": 1, "vxid": 1, "chain": 1, "error": "ERROR: there is no parameter $1 (SQLSTATE 42P02)"}

• parameter parse error:

{"task": 1, "vxid": 1, "chain": 1, "error": "failed to parse parameter \"1 month\": json: cannot unmarshal string into Go value of type []interface {}"}

• joined errors (task with two parameters: correct and incorrect):

{"task": 1, "vxid": 1, "chain": 1, "error": "ERROR: procedure F_CreatePartitions(date, date) does not exist (SQLSTATE 42883)\nfailed to parse parameter \"1 month\": json: cannot unmarshal string into Go value of type []interface {}"}

[coveralls]

Pull Request Test Coverage Report for Build 22749875293

Details

• 3 of 7 (42.86%) changed or added relevant lines in 2 files are covered.
• 4 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.03%) to 87.273%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
internal/pgengine/log_hook.go	0	4	0.0%

Files with Coverage Reduction	New Missed Lines	%
internal/pgengine/log_hook.go	4	81.08%

Totals
Change from base Build 21996564729:	0.03%
Covered Lines:	1728
Relevant Lines:	1980

---

💛 - Coveralls

[0xgouda]

@MaxaiZer I tried to reproduce the 3 cases you are describing using a pg_timetable instance built from master and I can't see them. I get all outputs for the Task execution failed message similar to your "After" section:

# no parameters, doesn't contain a pgconn.PgError struct
{"chain":39,"error":"ERROR: there is no parameter $1 (SQLSTATE 42P02)","level":"error","msg":"Task execution failed","task":39,"time":"2026-03-06T08:33:53+02:00","vxid":17179871472}

# 1 invalid parameter, doesn't contain struct with no actual error message
{"chain":11,"error":"json: cannot unmarshal string into Go value of type []interface {}","level":"error","msg":"Task execution failed","task":11,"time":"2026-03-06T08:12:29+02:00","vxid":17179870230}

# 2 parameters (1 correct and 1 incorrect), doesn't return empty error
{"chain":36,"error":"ERROR: invalid input syntax for type boolean: \"7\" (SQLSTATE 22P02)","level":"error","msg":"Task execution failed","task":36,"time":"2026-03-06T08:25:12+02:00","vxid":17179871259}

Am I missing something? can you add reproduction steps?

---

but I can still see the value of the below block that you added:

if parseErr := json.Unmarshal([]byte(val), &params); parseErr != nil {
	err = errors.Join(err, fmt.Errorf("failed to parse parameter %s: %w", val, parseErr))

[MaxaiZer]

@0xgouda Oh, I should have clarified: this is related to db logging (timetable.log table)

[0xgouda]

LGTM! Thanks for your contribution.