Connection Collation extension solves an underestimated problem in MySQL/MariaDB database management: the mismatch between the connection collation and the database collation.

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Testedn on Opencatt 3.0.5.0
You are welcome to send feedback about other versions.
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OpenCart, in its default configuration, does not explicitly set the connection collation when establishing the link with the MySQL/MariaDB server. This means the server falls back to its own default collation, which may differ from the one used when the store's database was originally created. With this extension, every database connection is initialized with the correct SET NAMES and SET collation_connection directives, ensuring full consistency between the connection and the database.

How It Works
The extension intercepts OpenCart's database connection layer and, immediately after the connection is opened, sends the collation directive configured by the administrator through the admin panel to the MySQL/MariaDB server. It is compatible with both mysqli and PDO drivers, supports all OpenCart versions from 3.x onwards, and works seamlessly on any MySQL 5.6+, MySQL 8.x, and MariaDB 10.x+ installation.

Configuration is straightforward: simply select the desired collation from the dropdown menu in the admin panel (Ex.: utf8mb4_unicode_ci, utf8mb4_general_ci, or utf8_unicode_ci) and the extension takes care of the rest, with no impact on performance and no code modifications required.


Keeping the connection collation identical to the database collation is not merely a technical preference — it is an operational necessity that directly impacts data correctness, query performance, and the overall security of your store.

1. Accurate Searches and Correct Sorting

When the connection collation matches the collation of the database columns, MySQL/MariaDB can perform string comparisons directly on indexes. Searches by product name, category, customer, or order return precise and complete results, correctly respecting comparison rules for accented characters, case sensitivity, and special characters across all languages.

2. Optimal Performance — No Implicit Conversion

With aligned collations, MySQL's query optimizer can fully leverage the indexes defined on the columns. When collations differ, the engine must perform an implicit collation coercion on every string comparison, rendering indexes unusable and forcing queries to fall back to full table scans. On a large product catalog, this can translate into response times ten times slower or worse.

3. Reliable Multilingual Support

Stores using extended Unicode characters — Arabic, Chinese, Japanese, emojis in product names, accented characters from Central and Eastern European languages — require the utf8mb4_unicode_ci collation. If the connection uses utf8_general_ci while the database is configured with utf8mb4, 4-byte characters are silently truncated or corrupted at write time.

4. Data Integrity Across All Text Fields

Data written and read with the same collation maintains full integrity. Customer names, addresses, product descriptions, and order notes are saved and retrieved exactly as entered, with no unwanted character transformations or silent data loss.

5. Compatibility with Backup and Migration Tools

When you export your database (e.g., with mysqldump) and re-import it onto another server, having a consistent connection collation ensures all data is transferred without alterations, making migrations and backups reliable and predictable across different server environments.

6. Extension and Plugin Compatibility

Third-party OpenCart extensions execute raw SQL queries that perform string comparisons or JOIN operations. When the connection collation matches the database collation, these queries work as expected without requiring patches or workarounds for every single extension installed on your store.

A collation mismatch is a particularly insidious problem because it often produces no explicit error messages — the damage manifests silently and progressively, sometimes going undetected for months.