Flask使用mysql查询，类似%%

Question

使用python3在flask中尝试mysql查询

SELECT title FROM Book WHERE title LIKE '%booktitlehere%';

从我的搜索表单的输入来看，这是一个尝试的烧瓶实现

^{pr2}$

当转到保存此表单的页面时，不会出现此错误

_mysql_异常。编程错误：不是所有参数都在字符串格式化期间转换

我尝试添加%%来转义%

likeString = "'%%" + search_string + "%%'"
# print(like)
cur.execute("""SELECT title FROM Book WHERE title LIKE %s;""",likeString)
rv = cur.fetchall()

但还是出错了

_mysql_exceptions.ProgrammingError: not all arguments converted during string formatting

也尝试了用双引号括住select

cur.execute("SELECT title FROM Book WHERE title LIKE %s;",likeString)

Answer 1

Double it：

likeString = "'%%" + search_string + "%%'"

cur.execute("""SELECT title FROM Book WHERE title LIKE %s;""", (likeString))

Answer 2

在sql命令中使用搜索字符串之前

search_string= f"%{search_string}%"

然后在sql命令中应用它

cur.execute("SELECT * FROM books WHERE title LIKE :searching_string ORDER BY id ",{"searching_string":search_string})

另外还可以降低
search_string= f"%{search_string}%".lower()

^{pr2}$

Answer 3

示例：

cari = "%" + request.form['cari'] +"%"

conn.execute("SELECT nama, harga FROM barang where nama LIKE %s OR harga LIKE %s", (cari, cari))