MySQL Character Sets and Collations: Essential Basic Configurations for Beginners

This article introduces MySQL character sets and collations. A character set is an encoding rule for storing characters (e.g., utf8mb4 supports full Unicode), while a collation determines how characters are compared and sorted (e.g., utf8mb4_general_ci is case-insensitive). Improper configuration can lead to garbled text, incorrect sorting (e.g., abnormal sorting of "张三"), or compatibility issues (e.g., old utf8 not supporting emojis). Configuration hierarchy priority: Column-level > Table-level > Database-level > Server-level, with default following server-level configuration. Commands like SHOW VARIABLES (for character set/collation), SHOW CREATE DATABASE/ TABLE are used to check configurations. Recommended configurations: Prioritize utf8mb4 character set. Modify my.cnf/ini file at server-level, and specify character sets/collations for databases/tables/columns using CREATE/ALTER statements. Common issues: Garbled text requires unified character set; emoji not displaying should switch to utf8mb4; incorrect sorting can be resolved by choosing a more precise collation. Best practices: Use utf8mb4 character set and collation (utf8mb4_general_ci for better performance or unicode_ci for precision). Avoid individual column-level configurations and regularly check configurations for consistency.