mysql建表时错误

CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(100)
    email VARCHAR(100)
);

CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    email VARCHAR(100)
);

ERROR 1044 (42000): Access denied for user 'testuser'@'localhost' to database 'testdb'

GRANT ALL PRIVILEGES ON testdb.* TO 'testuser'@'localhost';
FLUSH PRIVILEGES;

ERROR 1050 (42S01): Table 'users' already exists

DROP TABLE IF EXISTS users;
CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    email VARCHAR(100)
);

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'CHARACTER SET utf8mb4' at line 1

CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    email VARCHAR(100)
) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

ERROR 1293 (HY000): Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause

CREATE TABLE users (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    email VARCHAR(100),
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
) ENGINE=InnoDB;