postgresql sql 查询语法错误在 python 中的“convert_from”处或附近

Question

我认为这是一个简单的问题，如何在 python 中编写 sql 查询？

### python3 code
# ok 
row = await conn.fetchrow(
    'SELECT * FROM users WHERE email = $1', user_email)

# NOT ok
user_pw = await conn.fetch(                                                          
    'convert_from($1, $2)', row[2], 'UTF8') 

asyncpg.exceptions.PostgresSyntaxError：“convert_from”或附近的语法错误

Answer 1

我用以下代码修复了我的错误：

tmp_pw = await conn.fetch(
    'SELECT * FROM convert_from($1, $2)', row[2], 'UTF8')

# because, tmp_pw is  
#[<Record convert_from='$2a$12$PsXD/oaDXwC1Ffup842I/emQ3Bz26AWjQNsLBQipQ4gvRIFhUQAXb2'>]
# any suggestion is welcome.
user_pw = str(tmp_pw).strip('[]').strip('<>').split('=')[1].strip('\'')

# another method to get pw from Record (not tested):
# tmp_iter = iter(tmp_pw)
# user_pw = next(tmp_iter)