使用Python向MySQL表添加单个键值对

Question

我正在尝试从 python 向 mysql 表添加一个值。我已经尝试了大约五种不同的方法，但仍然收到错误消息，指出当我调用插入时，表中的其他键没有传递值。问题是我不想插入任何其他值，只想插入一个特定的键。这是我目前拥有的代码，提前感谢您的帮助

cursor.execute("SELECT * FROM SONG")
        result = cursor.fetchall()
        sname = str(input("What is the name of the song you are looking for: "))
        for row in result:
            title = row[0]
            if(title == sname):
                sql = ("INSERT INTO USER (s_id) VALUES (%s)")
                val = row[1]
                cursor.execute(sql, (val,))

mysql.connector.errors.DatabaseError：1364（HY000）：字段“userid”没有 默认值

CREATE TABLE USER
(username   VARCHAR(20),
userid      CHAR(3),
a_id        CHAR(3),
s_id        CHAR(3),
PRIMARY KEY (userid),
FOREIGN KEY (a_id) REFERENCES ALBUM(a_id),
FOREIGN KEY (s_id) REFERENCES SONG(s_id));
CREATE TABLE PLAYLIST
(p_name     VARCHAR(20),
p_id        CHAR(3)         NOT NULL,
userid      CHAR(3),
s_id        CHAR(3),
PRIMARY KEY (p_id),
FOREIGN KEY (userid) REFERENCES USER(userid),
FOREIGN KEY (s_id) REFERENCES SONG(s_id));

Answer 1

正确的方法是不使用 python，而只使用 MySQL 查询

sname = str(input("What is the name of the song you are looking for: "))
    sql = ("INSERT INTO USER (s_id) select id from SONG where name= '%s'")
    cursor.execute(sql)

https://www.w3schools.com/sql/sql_insert_into_select.asp