import { type DatabaseDriver } from "./schema/driver.ts";
interface SqlDialect {
    readonly driver: DatabaseDriver;
    placeholder(index: number): string;
    quoteIdentifier(identifier: string): string;
    nowExpression(): string;
    /** Render a Date as a literal this engine accepts for a timestamp column. */
    timestampValue(value: Date): string;
    returningClause(columns: string): string;
    ilikeOperator(): "ILIKE" | "LIKE";
    nullsLastSuffix(): string;
    castToText(expression: string): string;
    /** Conflict handling appended to an INSERT. Empty updates mean "do nothing". */
    upsertSuffix(conflictColumns: readonly string[], updateColumns: readonly string[]): string;
}
declare function dialectFor(driver: DatabaseDriver): SqlDialect;
declare function currentSqlDialect(): SqlDialect;
declare function useSqlDialect(driver: DatabaseDriver): SqlDialect;
/** Format a timestamp parameter for whichever engine is active. */
declare function sqlTimestamp(value?: Date): string;
declare function resetSqlDialect(): void;
declare function runWithSqlDialect<T>(driver: DatabaseDriver, callback: () => T | Promise<T>): T | Promise<T>;
export type { SqlDialect };
export { currentSqlDialect, dialectFor, resetSqlDialect, runWithSqlDialect, sqlTimestamp, useSqlDialect, };