Dialects

QUARK routes SQL generation through a dialect abstraction. Dialects are responsible for placeholders, identifier quoting, insert ID behavior, upsert syntax, and DDL operations.

Dialect	Constructor	Notes
PostgreSQL	quark.PostgreSQL()	$N placeholders, RETURNING, ON CONFLICT.
MySQL	quark.MySQL()	AUTO_INCREMENT, LAST_INSERT_ID, ON DUPLICATE KEY UPDATE.
MariaDB	quark.MariaDB()	MySQL-compatible upsert behavior (ON DUPLICATE KEY UPDATE). Treated as a distinct dialect for DDL edge cases.
SQLite	quark.SQLite()	In-memory friendly, RETURNING where supported.
MSSQL	quark.MSSQL()	IDENTITY, OFFSET/FETCH, MERGE upserts.
Oracle	quark.Oracle()	GENERATED AS IDENTITY, MERGE upserts.

Upsert mapping

user := User{Email: "alice@example.com", Name: "Alice Updated"}

err := quark.For[User](ctx, client).Upsert(
    &user,
    []string{"email"},
    []string{"name", "active"},
)

Dialect	Generated shape
PostgreSQL	ON CONFLICT (email) DO UPDATE SET ...
MySQL	ON DUPLICATE KEY UPDATE ...
MariaDB	ON DUPLICATE KEY UPDATE ...
SQLite	ON CONFLICT (email) DO UPDATE SET col = excluded.col
MSSQL	MERGE INTO ... USING ... WHEN MATCHED ...
Oracle	MERGE INTO ... USING ... WHEN MATCHED ...

Custom dialects

Custom or proprietary engines can be registered:

myDialect := &MyCustomDialect{}

quark.RegisterDialect("customdb", myDialect)

dialect, err := quark.DetectDialectByName("customdb")
if err != nil {
    return err
}

client, err := quark.New("customdb", dsn, quark.WithDialect(dialect))

DetectDialectByName looks up a registered dialect by name and returns (Dialect, error). Use RegisterDialect once at init time.

The dialect interface covers SQL generation, placeholder formatting, identifier quoting, and schema DDL.