Website Hacked with SQL Injection

Try reviewing Hardening_WordPress and https://blog.sucuri.net/2012/03/wordpress-understanding-its-true-vulnerability.html

The best security for a WordPress website is to get high-quality managed hosting somewhere like wpengine.com, pagely.com, getflywheel.com, pressable.com.

If you are on low-cost shared hosting, these can be helpful:
https://www.ads-software.com/plugins/wordfence/
https://www.ads-software.com/plugins/better-wp-security/
https://sucuri.net/

Thx for Replay ..
For Security iam using below Stuffs:

change prefix , change wp-config path and disable all access ,
Blocking Malicious IP , files permission 644
wp better security .
although my site is not secure .

although my site is not secure .

Why do you say that? Or more to the point: what are you doing that is not secure? That link that Esmi posted really is good stuff.

https://codex.www.ads-software.com/Hardening_WordPress

My developed site is a govt website and before it was in joomla . but now i redeveloped it with word press . the site is not will be hacked anyway
believe me…
i used all all of stuff as used for security . but somehow i don’t know why somebody try to hacked it with sql injection after live the website .
and my company blame to me why i developed it with wordpress.
I don’t know what is the problem . I am really tired.
i changed not only path permission removed all permission from database.
Lets See what happen with it.
and pardon me for my English written .

somebody try to hacked it with sql injection after live the website

Somebody tried to attack the site? Or was it actually hacked?

it’s not hacked but might be someone tried . i realized it when i saw access log and also sending warning mail.i used wp security . after that i changed database & cpanel userid & password.
now iam feeling unsafe.
i tried my best to keep it secure.

Make sure you are not using default login user id “admin” on wordpress!
Also you can install limited login attempt plugin to limit the user login to the site. Plugin is available for free on wordpress repository.

yes i did even i changed user login path “wp-admin” .
i used all stuffs for security .