# Common Issues After a MySQL Server Upgrade and How to Fix Them

If you encounter an error message similar to the following during the operation that you want to perform on the MySQL server:

```
Field 'field_name' doesn't have a default value
```

Then we recommend that you run the following query after building a MySQL connection:

**Up to PHP version 5.7 you should use the following code:**

```
mysql_query("SET SESSION sql_mode = ''");
```

**From PHP version 7.0 or higher, you should use the following line of code:**

```
mysqli_query("SET SESSION sql_mode = ''");
```