can't insert json data into mysql database in php

Question

I have a json format data without key value pair. when i insert data my table only the 1st data is inserted(of the array). how i insert the all data into my databse table?

<?php

$mysqli = new mysqli('localhost','root','','user');
$my_json_data = file_get_contents('./jason_data.txt');
$my_data = json_decode($my_json_data,true);


foreach($my_data as $data){

    $sql = "INSERT INTO demo_table (data) VALUES ('$data');";
    $mysqli->query($sql);
}

echo "done...";

?>

my database table name is 'demo_table' and json data fromat like this

["hello-world","sample-page","privacy-policy","2-revision-v1","the-banner-title"]

which is a .txt format in the same directory of my workspace

my table schema is like this

CREATE TABLE `demo_table` (
 `id` int(5) NOT NULL,
 `data` varchar(255) NOT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

Answer 1

Seems you have not a proper primary key.

Try create in the demo_table a proper primary key based on auto increment column

based on your schema add autoincrement

CREATE TABLE `demo_table` (
  `id` int(5) NOT NULL  AUTO_INCREMENT,
  `data` varchar(255) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

in this each row inserted have a automatic different primary key .. otherwise the first insertion create an id = 0 and the second try to do the same ..but 0 already exist