MySQL 中 = 和 = 有什么区别

MySQL中=和:=的区别

sql
UPDATE students SET name = 'John' WHERE id = 1;

sql
SELECT name INTO @student_name FROM students WHERE id = 1;

sql
-- 创建一个名为students的表
CREATE TABLE students (
  id INT,
  name VARCHAR(50)
);
-- 向students表中插入一些学生信息
INSERT INTO students (id, name) VALUES (1, 'Tom');
INSERT INTO students (id, name) VALUES (2, 'Alice');
-- 使用=将id为1的学生的姓名修改为"John"
UPDATE students SET name = 'John' WHERE id = 1;
-- 使用:=将id为1的学生的姓名赋给变量@student_name
SELECT name INTO @student_name FROM students WHERE id = 1;
-- 输出变量的值
SELECT @student_name;