Dialect Interface

Dialects encapsulate database-specific DDL and parameter placeholder style. Go Audit ships with three implementations — PostgreSQL, MySQL, and SQLite.

Types

type DialectType = dialect.Type // string alias: "postgres", "mysql", "sqlite", …

const (
    PostgreSQL DialectType = "postgres"
    MySQL      DialectType = "mysql"
    SQLite     DialectType = "sqlite"
)

The Interface

type Dialect interface {
    Name() Type
    CreateDataTableSQL(table string) string
    CreateAPITableSQL(table string) string
    CreateIndexesSQL(table string) []string
    CreateAPIIndexesSQL(table string) []string
    Placeholder(n int) string
}

Method	Purpose
`Name()`	Returns the dialect's `Type` identifier.
`CreateDataTableSQL`	`CREATE TABLE IF NOT EXISTS ...` for the data audit table.
`CreateAPITableSQL`	Same for the API audit table.
`CreateIndexesSQL`	List of `CREATE INDEX` statements (empty for MySQL, which declares indexes inline).
`CreateAPIIndexesSQL`	Same for API audit indexes.
`Placeholder(n)`	Parameter placeholder for `n`-th arg (`$1` for Postgres, `?` for MySQL/SQLite).

Built-In Dialects

audit.PostgreSQL — JSONB + GIN indexes; richest JSON query capability downstream (though Go Audit itself does not push JSON predicates into queries).
audit.MySQL — JSON column type; inline B-tree indexes; InnoDB.
audit.SQLite — stores JSON as TEXT; B-tree indexes; perfect for tests.

Registering a Custom Dialect

Implement audit.Dialect for your database.

audit.RegisterDialect(audit.DialectType("cockroach"), myDialect)

Use the same name in Config:

audit.New(sqlDB, audit.Config{
    Dialect: audit.DialectType("cockroach"),
})

Registration is thread-safe (guarded by sync.RWMutex), so you can register additional dialects from init code.

When Would You Need This?

A cloud database variant (Aurora, AlloyDB, Spanner) where the standard dialect needs tweaks.
An analytics-focused backend like DuckDB or ClickHouse for read patterns that benefit from columnar storage.

Helper: `audit.DialectFor`

d := audit.DialectFor(audit.PostgreSQL)
// returns the registered Dialect (nil if unknown)

Rarely needed directly — the constructor does this lookup for you — but useful for tests or custom tooling.