golang-migrate/migrate · error

no config

Error message

no config

What it means

The ClickHouse driver defines ErrNilConfig ("no config") and returns it from WithInstance, WithConnection, and extractCustomQueryParams when the *Config argument is nil. It signals that driver construction was attempted without any configuration object, so there is nothing to read database name, table, or engine settings from.

Source

Thrown at database/clickhouse/clickhouse.go:26

	"net/url"
	"strconv"
	"strings"
	"sync/atomic"
	"time"

	"github.com/golang-migrate/migrate/v4"
	"github.com/golang-migrate/migrate/v4/database"
	"github.com/golang-migrate/migrate/v4/database/multistmt"
)

var (
	multiStmtDelimiter = []byte(";")

	DefaultMigrationsTable       = "schema_migrations"
	DefaultMigrationsTableEngine = "TinyLog"
	DefaultMultiStatementMaxSize = 10 * 1 << 20 // 10 MB

	ErrNilConfig = fmt.Errorf("no config")
)

type Config struct {
	DatabaseName          string
	ClusterName           string
	MigrationsTable       string
	MigrationsTableEngine string
	MultiStatementEnabled bool
	MultiStatementMaxSize int
}

func init() {
	database.Register("clickhouse", &ClickHouse{})
}

func WithInstance(conn *sql.DB, config *Config) (database.Driver, error) {
	if config == nil {
		return nil, ErrNilConfig

View on GitHub (pinned to 01a9643f14)

Solutions

1. Construct a config first: use clickhouse.WithURL(dsn) which parses the DSN into a Config, or build &Config{...} manually and pass it to WithInstance.
2. Check for nil before calling WithInstance/WithConnection and return your own descriptive error.
3. Ensure the code path that was supposed to initialize the config actually ran (no early returns skipping initialization).

Example fix

// before
ch, err := clickhouse.WithInstance(conn, nil)
// after
cfg := &clickhouse.Config{DatabaseName: "default", MigrationsTable: clickhouse.DefaultMigrationsTable}
ch, err := clickhouse.WithInstance(conn, cfg)

if cfg == nil {
    return fmt.Errorf("clickhouse config must not be nil")
}

func validClickhouseConfig(cfg *clickhouse.Config) bool {
    return cfg != nil && cfg.MigrationsTable != ""
}

ch, err := clickhouse.WithInstance(conn, cfg)
if err != nil {
    if errors.Is(err, clickhouse.ErrNilConfig) {
        return fmt.Errorf("clickhouse driver requires a config; use clickhouse.WithURL")
    }
    return err
}

When it happens

Trigger: Passing nil as the config to clickhouse.WithInstance(conn, nil) or clickhouse.WithConnection(conn, nil); calling extractCustomQueryParams with a nil config.

Common situations: Building a driver programmatically without calling clickhouse.Config or WithURL first; a config variable that was declared but never initialized; an early-return path that lost the config value.

Related errors

• no config
• no config
• no keyspace provided
• no config
• no database name

AI-assisted analysis of golang-migrate/migrate@01a9643f14 (2026-09-02). Data as JSON: /api/errors/9f53696915f18573. Report an issue: GitHub.