Why Are My Persian Characters Garbled When Migrating Data from an Old Script to MySQL?

Mystery of Misencoded Data in MySQL: The Case of Old and New Scripts

In the realm of data storage and retrieval, it's not uncommon to encounter unexpected behavior when working with different systems. Such is the case with the puzzling encoding discrepancy encountered by a developer attempting to migrate data from an old to a new script.

The Problem: Garbled Characters

The developer faced a peculiar issue: Persian characters encoded using UTF-8 in the old script appeared as garbled text when using the new script, even though both scripts supposedly used the same character set (UTF-8).

The Suspect: Database Configuration

Initial troubleshooting efforts focused on database settings. The old script employed a custom database engine, while the new script used MySQL. To ensure compatibility, the developer verified that the character set and collation for the MySQL database were set to UTF-8 and UTF-8_persian_ci, respectively.

The Strange Behavior

Despite setting the correct character set and collation, the discrepancy persisted. The old script continued to display Persian characters correctly, while the new script still showed garbled text.

The Root Cause: A Connection Mishap

After delving deeper into the issue, the developer discovered a subtle but crucial detail: the database connection used by the old script was set to Latin1. This apparently harmless setting had significant implications for the data encoding.

How It Happened

When the data was initially inserted into the database using the old script, PHP sent the UTF-8 encoded string to the database. Since the connection was set to Latin1, the database interpreted the bytes representing the Persian characters as Latin1 values. Consequently, the characters were stored in the database in the incorrect encoding.

The Solution: Database Conversion

To resolve the engraving error, the developer had to convert the data in the database to the correct UTF-8 format. This could be achieved using the following SQL statement:

SELECT CONVERT(BINARY CONVERT(field_name USING latin1) USING utf8) FROM table_name

Once the conversion was complete, the Persian characters were stored in the database in their correct UTF-8 encoding. The new script could now retrieve and display the data properly, matching the output of the old script.

The above is the detailed content of Why Are My Persian Characters Garbled When Migrating Data from an Old Script to MySQL?. For more information, please follow other related articles on the PHP Chinese website!