MySQL如何快速检测字段值是否包含大写

-- 检测任意位置包含大写
SELECT * FROM table 
WHERE column REGEXP BINARY '[A-Z]';

SELECT * FROM table 
WHERE column RLIKE '[A-Z]';

-- 检测全大写（排除数字符号）
SELECT * FROM table 
WHERE column REGEXP BINARY '^[A-Z]+$';

SELECT * FROM table 
WHERE column RLIKE  '^[A-Z]+$';

-- 检测首字母大写（这种的识别不出首字母是数字的数据）
SELECT * FROM table 
WHERE BINARY LEFT(column,1) = UPPER(LEFT(column,1));

-- ASCII码检测（A-Z=65-90）（下面的N代表第几位是大写）
SELECT * FROM table 
WHERE ORD(SUBSTRING(column,N,1)) BETWEEN 65 AND 90;

-- 查询时指定区分大小写（精确查询 把Column字段的字符集设置成utf8mb4_bin ，会区分大小写 ）
SELECT * FROM table 
WHERE column COLLATE utf8mb4_bin = 'TargetValue';

ALTER TABLE users 
ADD COLUMN name_upper VARCHAR(255) 
GENERATED ALWAYS AS (UPPER(username)) VIRTUAL,
ADD INDEX idx_upper(name_upper);

ALTER TABLE products 
ADD COLUMN initial CHAR(1) 
GENERATED ALWAYS AS (UPPER(LEFT(code,1))) STORED,
ADD INDEX idx_initial(initial);

SELECT 1 FROM table WHERE column REGEXP BINARY ‘[A-Z]' LIMIT 1;

-- 用户表检测邮箱大小写重复
SELECT email 
FROM (
  SELECT LOWER(email) AS lower_email, 
         GROUP_CONCAT(email) AS duplicates
  FROM users 
  GROUP BY lower_email 
  HAVING COUNT(*) > 1
) t 
WHERE duplicates REGEXP BINARY '[A-Z]';