MySQL一条SQL修改全库字段的编码格式

-- 1. 修改数据库编码
ALTER DATABASE /* database name */ CHARACTER SET = utf8mb4 COLLATE = utf8mb4_unicode_ci;

-- 2. 生成修改表编码的语句
SELECT
  CONCAT(
  'ALTER TABLE ', 
  TABLE_NAME, 
  ' CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; ') AS alter_sql
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA='/* database name */' 
  AND TABLE_TYPE='BASE TABLE'
ORDER BY TABLE_NAME;

-- 3. 生成修改所有表的所有 varchar 类型字段编码的语句
-- 注意：需要手动去除视图的修改语句
SELECT 
  CONCAT(
  'ALTER TABLE ', TABLE_NAME, ' CHANGE ', 
  '`', COLUMN_NAME, '` ', 
  '`', COLUMN_NAME, '` ', 
  COLUMN_TYPE,
  ' CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;') AS alter_sql
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA='/* database name */' 
  AND DATA_TYPE='varchar'
ORDER BY TABLE_NAME, COLUMN_NAME;

生成语句如下，直接复制执行即可