mysql把一个表部分数据update

-- 更新单个员工的薪水
UPDATE employees
SET salary = 50000
WHERE employee_id = 1;

-- 更新多个员工的薪水（例如，所有经理的薪水增加10%）
UPDATE employees
SET salary = salary * 1.1
WHERE job_title = 'Manager';

-- 使用CASE语句进行批量更新
UPDATE employees
SET salary = CASE
    WHEN job_title = 'Developer' THEN salary * 1.05
    WHEN job_title = 'Designer' THEN salary * 1.07
    ELSE salary
END;

-- 检查条件是否正确
SELECT * FROM employees WHERE employee_id = 1;

-- 确认权限
SHOW GRANTS FOR 'username'@'localhost';

-- 创建索引
CREATE INDEX idx_employee_id ON employees(employee_id);

-- 分批更新
UPDATE employees
SET salary = salary * 1.1
WHERE job_title = 'Manager'
LIMIT 1000;