1.php passes value to javascript
How php passes value to javascript: you need to put quotation marks outside the tag
document.getElementById("titor"+a+ b).innerHTML="";
Note: In fact, my original understanding was wrong, php is a dynamic display language. In fact, in the echo that displays the relevant text, because the original one does not have quotation marks, it is natural to add quotation marks
2. Timestamp conversion
strtotime can convert the datetime in mysql Convert to timestamp;
3. Regarding data rounding
number_format($time*$deposit_money*0.05/365,2) The following 2 means retaining 2 decimal places, which is Rounded. Another way echo sprintf("%.2f", $number); without rounding
1.GRANT and REVOKE commands:
Grant and cancel permissions for mysql users, which are divided into four levels Global - Database - Table - Column
2. Create index
can make the query faster create index statement
3. Retrieve variable
$_POST $_GET $_REQUEST
4. heredoc syntax
echo <<
line 2
line 2
theEnd
everything in theEnd Treated as a string