<?php namespace DBDiff\SQLGen\Dialect;

interface SQLDialectInterface {

/** Quote a single identifier (table, column, index name). */

public function quote(string $name): string;

/** The PDO driver string: mysql | pgsql | sqlite */

public function getDriver(): string;

/**

* Whether this dialect is MySQL-only.

* When true, MySQL-specific diff objects (Engine, Charset, Collation)

* will be handled; when false those DiffToSQL classes return empty strings.

*/

public function isMySQLOnly(): bool;

/**

* DROP INDEX statement.

* MySQL: ALTER TABLE `t` DROP INDEX `key`

* Postgres/SQLite: DROP INDEX "key"

*/

public function dropIndex(string $table, string $key): string;

/**

* DROP TRIGGER statement.

* MySQL: DROP TRIGGER IF EXISTS `trigger`

* Postgres: DROP TRIGGER IF EXISTS "trigger" ON "table"

* SQLite: DROP TRIGGER IF EXISTS "trigger"

*/

public function dropTrigger(string $trigger, string $table): string;

/**

* ADD COLUMN statement.

* $colDef is the full column DDL fragment (already quoted), e.g.

* MySQL: `col` varchar(255) NOT NULL

* Postgres/SQLite: "col" varchar(255) NOT NULL

*

* MySQL omits the COLUMN keyword for backwards-compat with existing baselines.

* Postgres and SQLite always include COLUMN.

*/

public function addColumn(string $table, string $colDef): string;

/**

* DROP COLUMN statement.

* $col is the bare (unquoted) column name.

*

* MySQL omits the COLUMN keyword for backwards-compat with existing baselines.

* Postgres and SQLite always include COLUMN.

*/

public function dropColumn(string $table, string $col): string;

/**

* ALTER COLUMN / CHANGE COLUMN.

* $col is the bare column name.

* $newDef is the full column DDL fragment produced by the adapter,

* e.g. `col` varchar(255) NOT NULL (MySQL)

* or "col" varchar(255) NOT NULL (Postgres/SQLite)

*

* Returns the complete statement(s) including trailing semicolons.

*/

public function changeColumn(string $table, string $col, string $newDef): string;

/**

* DROP CONSTRAINT statement.

* $schema is the full constraint DDL used to detect the constraint type.

*

* MySQL requires DROP FOREIGN KEY for FK constraints; DROP CONSTRAINT

* only works for CHECK constraints. Postgres and SQLite use the

* standard DROP CONSTRAINT for all types.

*/

public function dropConstraint(string $table, string $name, string $schema): string;

}