Topic: database query help

[blainec]

I'm new to sql and PHP but I'm trying

I use mariadb. I am  trying to query information_schema.tables [tablename] TABLE_ROWS. to get the number of rows.
I have tried using COUNT function,  but that doesn't seem to work for me, s o I thought this would give me the info I need.

I hope there is a  SQL wizard out there that can help me...

Thanks
Blaine

[davidefa]

I think you can use something like this ( insert appropriate values for host, username, password, db_name and table_name ):

Code: [Select]

$link = mysqli_connect("host", "username", "password","db_name");
$result = mysqli_query($link, "SELECT count(*) FROM table_name");
$num_rows = mysqli_fetch_row($result)[0];
echo "table_name rows: $num_rows\n";

[blainec]

not returning anything

[bchwdlks]

I use a mariadb database on an RPi. It is feeding a Meteotemplate web page. My work career involved many years of Unix databases so I almost always use command line utilities. This is simple record count from a single table


pi@mcgee: ~
$  mysql -u USERNAME -D davis -A --password=PASSWORD -e "select count(*)  from alldata where DateTime > '2020-01-01 00:00:01';"
+----------+
| count(*) |
+----------+
|   235661 |
+----------+

[mcrossley]

not returning anything

Have you checked your mysql log files for any errors?

[davidefa]

a) you can execute the 'select' ( SELECT count(*) FROM table_name ) in phpmyadmin, it should return 1 value
b) you can execute the following code ( only added a few debug prints )

Code: [Select]

<?php
$link = mysqli_connect("host", "username", "password","db_name");
echo "connect error: ".mysqli_error($link)."<br>\n";
$result = mysqli_query($link, "SELECT count(*) FROM table_name");
echo "query error: ".mysqli_error($link)."<br>\n";
$num_rows = mysqli_fetch_row($result)[0];
echo "fetch_row error: ".mysqli_error($link)."<br>\n";
echo "table_name rows: $num_rows<br>\n";
?>
P.S.
insert appropriate values for host, username, password, db_name and table_name