查询数据

56.5 查询数据

SELECT 列 FROM 表 WHERE 条件 ORDER BY 列 LIMIT 条数。

fetchone() 取一行（元组），fetchall() 取全部，fetchmany(n) 取 n 条。

LIKE 模糊匹配：% 表示任意多个字符，_ 表示一个字符。

条件查询与排序

import sqlite3

with sqlite3.connect('school.db') as conn:
    cur = conn.cursor()
    cur.execute(
        'SELECT name, score FROM students WHERE score >= ? ORDER BY score DESC LIMIT ?',
        (80, 5)
    )
    for name, score in cur.fetchall():
        print(name, score)

LIKE 模糊查姓名

import sqlite3

keyword = '小'  # 实际项目来自 input
with sqlite3.connect('school.db') as conn:
    cur = conn.execute(
        "SELECT name, score FROM students WHERE name LIKE ?",
        (f'%{keyword}%',)
    )
    print(cur.fetchall())