比较运算符
57.8 比较运算符
= 等于,!= 或 <> 不等于,> >= < <= 大小比较。
比较 NULL 必须用 IS NULL,写 =NULL 结果不对。
分数段筛选
import pymysql
conn = pymysql.connect(host='127.0.0.1', user='root', password='root', database='py_demo', charset='utf8mb4')
try:
with conn.cursor() as cur:
cur.execute('SELECT name, score FROM students WHERE score >= %s', (90,))
print('90分及以上:', cur.fetchall())
cur.execute('SELECT name, score FROM students WHERE score <> %s', (60,))
print('不是60分的:', cur.fetchall())
finally:
conn.close()