For mysql escape character insertion, query, and display problems, Dial

Mysql escape character insertion, query, and display problems, dial RT, usually php + mysql single quotes, "\" symbol insertion generally uses addslashes () method & nbsp; if, insert $ varstr & nbsp ;=& nbsp; test' \. The problem is as follows: 1. with addslashes (), insert, insert, and then insert, query, and display mysq mysql escape characters.
RT, which is a single quotation mark in php + mysql. the "\" symbol is inserted in the addslashes () mode.

Assume that $ varstr = is inserted Test '\, The problem is as follows:
1. with addslashes (), after insert is inserted, the storage format in mysql is test' \, or test \'\\?

3. after the select statement is selected, echo $ varstr; is it test' \ or test \'\\?

2. do I need to add addslashes () when selelct queries with this variable string as the condition ()?

Mysql has a headache about escape characters. I hope experts can give me some help. thank you! Mysql? Escape character? Share special characters:
------ Solution --------------------
Http://php.net/manual/zh/function.mysql-real-escape-string.php
------ Solution --------------------
The storage format in mysql is test '\
Echo $ varstr; display as test '\

Do I need to add addslashes () when selelct queries with this variable string as the condition ()?
Yes