从没有字符串格式的sqlite中检索文本以进行比较

Question

将字符串保存到 sqlite 表中，再次检索它并将其与原始数据进行比较需要一些过滤器才能工作，我不知道究竟是为什么。

tl;博士 我如何从 SQLITE DB 中检索字符串数据而不需要 Filter Nr 3 因为它对更复杂的字符串很危险？

import sqlite3

RAWSTRING = 'This is a DB Teststing'

# create database and table
currentdb = sqlite3.connect('test.db')
currentdb.execute('''CREATE TABLE tickertable (teststring text)''')

# enter RAWSTRING into databasse
currentdb.execute('''INSERT INTO tickertable VALUES(?);''', (RAWSTRING,))

# get RAWSTRING from database
cursorObj = currentdb.cursor()
cursorObj.execute('SELECT * FROM tickertable')
DB_RAWSTRING = cursorObj.fetchall()
currentdb.commit()
currentdb.close()

# Prints This is a DB Teststing
print('originalstring : ', RAWSTRING)

# Prints [('This is a DB Teststing',)]
print('retrieved from DB: ', DB_RAWSTRING)

# Get first entry from List because fetchall gives a list
FILTER1_DB_RAWSTRING = DB_RAWSTRING[0]

# Convert the Listelement to String because its still a listelement and comparing fails to string
FILTER2_DB_RAWSTRING = str(FILTER1_DB_RAWSTRING)

# Remove annoying db extra characters and i dont know why they exist anyway 
FILTER3_DB_RAWSTRING = FILTER2_DB_RAWSTRING.replace("'", "").replace("(", "").replace(")", "").replace(",", "")

if RAWSTRING == FILTER3_DB_RAWSTRING:
    print('Strings are the same as they should')
else:
    print('String are not the same because of db weirdness')

Answer 1

这就是你的问题：fetchall 返回一个元组的列表。这意味着将它们转换为字符串会在每行周围加上讨厌的括号，在每行的每个元素之间放置逗号。如果您想从每一列中检索原始信息，可以通过索引元组来完成：

entries = cursorObj.fetchall()
first_row = entries[0]
first_item = first_row[0]
print(first_item)

这应该只打印数据库中第一行和第一列的内容。如果没有，请告诉我！

大卫