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This page documents Maho's database adapter interface and its implementations that provide a robust, modern database abstraction layer. At its core, Maho uses Doctrine DBAL 4.x as the database abstraction engine, encapsulated in adapter classes implementing Maho\Db\Adapter\AdapterInterface. This system supports multiple database platforms while exposing a consistent API for data access, query building, transaction management, and schema operations.
Supported database platforms currently include:
pdo_mysql driver.pdo_pgsql driver.pdo_sqlite driver.These platforms are supported with dedicated PDO adapter classes extending an abstract base adapter providing platform-agnostic logic.
This interface and implementation enable multi-platform compatibility of Maho’s resource models and collections without requiring application code changes per database.
The database adapter interface acts as a bridge between Maho's high-level model/resource architecture and the low-level Doctrine DBAL connection.
Diagram: Maho Database Adapter Layer Integration
Mage_Core_Model_Abstract (models) and Maho\Data\Collection\Db rely on resource classes in Mage_Core_Model_Resource_Abstract and Mage_Core_Model_Resource_Db_Abstract.AdapterInterface.AbstractPdoAdapter forms the base implementation, relying on Doctrine DBAL’s Connection.Maho\Db\Select class wraps Doctrine's query builder, offering an intuitive query builder interface.Mysql, Pgsql, Sqlite) implement platform nuances relating to driver name, SQL modes, connection options, and dialect quirks.Maho\Db\Adapter\AdapterInterfaceThe AdapterInterface declares constants and method signatures required by all database adapters, ensuring a uniform API. It provides constants used for creating index types, defining foreign key actions, and standard date formats while prescribing:
beginTransaction, commit, rollBack).select() returns Maho\Db\Select).| Feature | MySQL Adapter | PostgreSQL Adapter | SQLite Adapter |
|---|---|---|---|
| Driver Name | pdo_mysql | pdo_pgsql | pdo_sqlite |
| Quote Character | Backtick ` | Double quotes " | Double quotes " |
| Statement Class | \Maho\Db\Statement\Pdo\Mysql | \Maho\Db\Statement\Pdo\Pgsql | \Maho\Db\Statement\Pdo\Sqlite |
| DDL Cache Prefix | DB_PDO_MYSQL_DDL | DB_PDO_PGSQL_DDL | DB_PDO_SQLITE_DDL |
Platform-specific classes primarily override initialization details (eg., driver name, connection options, SQL dialects).
| Method | Return Type | Description |
|---|---|---|
getConfig() | array | Returns the adapter configuration array. |
getConnection() | \Doctrine\DBAL\Connection | Returns the underlying Doctrine DBAL connection object. |
select() | Maho\Db\Select | Returns a new query builder instance. |
beginTransaction() | self | Initiates a database transaction with nesting support. |
commit() | self | Commits the current transaction, honoring nesting. |
rollBack() | self | Rolls back the current transaction, aborting all nesting. |
fetchAll() | array | Executes a query and fetches all results as an array. |
query() | Statement | Executes a raw SQL query, returns a statement. |
The detailed method implementations provide facilities such as safely quoting identifiers (tables, columns) and value binding with parameterized queries.
Maho exposes adapter methods to emit platform-specific SQL constructs with a unified interface:
| Helper | Purpose | Example SQL (MySQL / PgSQL / SQLite) |
|---|---|---|
getConcatSql(columns, separator) | Concatenates strings with separator | CONCAT_WS(sep, cols...) / `col1 |
getCheckSql(condition, truePart, falsePart) | Emulates IF conditionals | IF(cond, truePart, falsePart) / CASE WHEN cond THEN ... ELSE ... END |
getIfNullSql(expr, fallback) | Returns fallback for NULL expressions | IFNULL(expr, fallback) / COALESCE(expr, fallback) |
Date/time interval units are represented with constants such as INTERVAL_SECOND, INTERVAL_MINUTE, etc., mapped internally to platform-specific units.
SECOND, MINUTE, HOUR, DAY, MONTH, YEAR.strftime function with units like 'seconds', 'minutes', 'hours', 'days', 'months', and 'years'.Adapters internally translate these units to support cross-platform SQL generation.
Maho's database adapter supports nested transactions with an internal counter. This pattern preserves consistent transaction semantics regardless of whether the underlying driver supports true nested transactions.
rollBack() is called at any nesting level, the entire transaction is rolled back immediately, and the counter resets to zero, preventing partial commits.Maho's database abstraction supports schema-level operations via data definition language (DDL) manipulations integrated with Doctrine DBAL’s schema API.
A key modernization is converting MySQL-only TIMESTAMP columns to DATETIME:
CURRENT_TIMESTAMP is preserved only if explicitly present; others are dropped.ON UPDATE CURRENT_TIMESTAMP clauses are removed from schema for consistency.Because SQLite lacks several MySQL/PostgreSQL built-in functions, the SQLite adapter registers custom user-defined functions:
REGEXP: Uses PHP's preg_match to support regex matching in SQL queries.GREATEST and LEAST: Emulated using PHP's max() and min() for scalar argument lists.This ensures compatibility of queries using these functions regardless of platform.
Maho CLI commands provide convenient utilities to interact directly with the database using configured credentials:
db:connectmysql, psql, or sqlite3) using credentials from Maho’s configuration.db:queryMaho's Database Adapter Interface provides:
Maho\Db\Select.These design choices modernize Maho's data layer for reliability, maintainability, and extensibility across diverse deployment environments.
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