The database character encoding settings are incorrect: Inconsistency between the database character encoding and the connection character encoding can lead to garbled characters.
Incorrect character set settings in the database tables can result in garbled text.
Incorrectly setting the character set for the database connection can result in garbled text when connecting to the database.
When inserting data into a database, not specifying the character set may result in data corruption.
The data in the database is corrupted: The data itself is corrupt, resulting in the appearance of corrupted characters when reading and displaying it.
The database version does not support the character set: The database version is too old to support the current character set being used, resulting in garbled text.