checkbook balance scripting

[Barand]

10 minutes ago, mconte said:

your version might not support MAX()

Which versions don't? I haven't come across one.

[phppup]

Yes, MCONTE, both of those seem to work, but apparently mysqli_insert_id($link); works ONLY during an INSERT and not as a method to SELECT (independent of an INSERT in the same script).

Barand, I have a simple table being displayed row by row that is giving me results from other script efforts.  Didn't want to waste space by posting it.

            echo "</tr>";
        while($row = mysqli_fetch_array($result)){
            echo "<tr>";
                echo "<td>" . $row['id'] . "</td>";
                echo "<td>" . $row['first_name'] . "</td>";
                echo "<td>" . $row['last_name'] . "</td>";
                echo "<td>" . $row['email'] . "</td>";

 

Edited February 5, 2020 by phppup

[Barand]

That has nothing to do with your problem of finding the MAX(id), although it does show that you are capable, sometimes, of processing the results of a query.

[mconte]

18 minutes ago, Barand said:

Which versions don't? I haven't come across one.

I guess prior to 4.0 🙄

 

@phppup please do an "explain persons;" and show us the results

...is your id field a string??

[Barand]

16 minutes ago, mconte said:

"explain persons;"

Do you mean "describe persons"?

NM - I see they do the same thing

mysql> describe pup;
+------------------+--------------+------+-----+---------+----------------+
| Field            | Type         | Null | Key | Default | Extra          |
+------------------+--------------+------+-----+---------+----------------+
| id               | int(11)      | NO   | PRI | NULL    | auto_increment |
| name             | varchar(20)  | YES  |     | NULL    |                |
| amount           | decimal(8,2) | YES  |     | NULL    |                |
| transaction_date | datetime     | YES  |     | NULL    |                |
+------------------+--------------+------+-----+---------+----------------+
4 rows in set (0.01 sec)

mysql> explain pup;
+------------------+--------------+------+-----+---------+----------------+
| Field            | Type         | Null | Key | Default | Extra          |
+------------------+--------------+------+-----+---------+----------------+
| id               | int(11)      | NO   | PRI | NULL    | auto_increment |
| name             | varchar(20)  | YES  |     | NULL    |                |
| amount           | decimal(8,2) | YES  |     | NULL    |                |
| transaction_date | datetime     | YES  |     | NULL    |                |
+------------------+--------------+------+-----+---------+----------------+
4 rows in set (0.00 sec)

I only ever used explain with queries, not tables.

Edited February 5, 2020 by Barand

[phppup]

Field            Type    Null   Key  Default   Extra
id              int(11)    NO    PRI   NULL   auto_increment
first_name  varchar(30)    NO          NULL
last_name   varchar(24)    NO          NULL
email       varchar(70)    NO    UNI   NULL
sum             int(11)    NO          NULL

Persons is a simple table made up of some simple columns:  id, first_name, last_name, email, sum.

 

Edited February 5, 2020 by phppup

[mconte]

are you seeing an error from "select max(id) from persons;"

[phppup]

$sql = "SELECT MAX(id) FROM persons" ; 

if($result = mysqli_query($conn, $sql)){
    if(mysqli_num_rows($result) > 0){

 echo "<br /><br />ROW ".$row['id']."<br /><br />";   
    }
}

gives me:

ROW

and an ERROR message of   "Notice: Undefined index: id"

[ginerjm]

Probably cause the selected value is named "max(id)" or something similar.  Change the query to provide a name for the function result.

select max(id) as maxid

should do it and then you reference 'maxid' for your value.

[phppup]

select max(id) as maxid resulted in:

ERROR: Could not able to execute select max(id) as maxid. Unknown column 'id' in 'field list'

 

$sql ="select max(id) FROM persons as maxid";   still provided NO result

 

Edited February 7, 2020 by phppup

[cyberRobot]

42 minutes ago, phppup said:

...and an ERROR message of   "Notice: Undefined index: id"

You need to fetch the row and assign it to $row. Examples can be found here:
https://www.php.net/manual/en/mysqli-result.fetch-assoc.php

[Barand]

Works fine for me

mysql> select * from pup;
+----+-------+--------+---------------------+
| id | name  | amount | transaction_date    |
+----+-------+--------+---------------------+
|  1 | Curly |  10.00 | 2020-01-01 10:00:00 |
|  2 | Larry |  20.00 | 2020-01-15 12:30:00 |
|  3 | Mo    |  15.00 | 2020-02-01 09:00:00 |
|  4 | Peter |  -5.00 | 2020-02-01 10:30:00 |
|  5 | Paul  |  10.00 | 2020-02-02 11:30:00 |
|  6 | Mary  |   5.00 | 2020-02-02 12:15:00 |
+----+-------+--------+---------------------+
6 rows in set (0.00 sec)

mysql> select MAX(id) as maxid FROM pup;
+-------+
| maxid |
+-------+
|     6 |
+-------+
1 row in set (0.01 sec)

or

<?php
    $res = $conn->query("SELECT MAX(id) as maxid FROM pup");
    $row = $res->fetch_assoc();
    echo $row['maxid'];               //--> 6
?>

 

Edited February 7, 2020 by Barand

[phppup]

Got it working.

Cleared up my error messages.

Even re-wrote it in Procedural style for my clarity.

Thank you all for your input.

Thank you, <strong> sensei </strong>