02-20-2019
Quote:
Originally Posted by
figaro
I have a big, ugly query which is quadratic in the input size and therefore want to display an approximate completion time prior to sending it off:
I don't see the link between what you want and the query and like you have said it's not correct. So, to analyze the query you have the explain command to get information about the plan that will be used and from there you can estimate quick query and slow query.
See the official web site for "EXPLAIN"
The other option is to do it on the application side.
8 More Discussions You Might Find Interesting
1. Programming
Hi there,
I have a hierarchical database that include 4 tables. Table A is the parent of B, B is Parent of C, C is parent of D. If I want to query everything in D that is associated with A.name, how do I do that? Thanks!
YanYan (0 Replies)
Discussion started by: pinkgladiator
0 Replies
2. Shell Programming and Scripting
Hi there, I have a table that stores multiple records for many different servers, each of which is timestamped ... I wanted to write a query that would enable me to only output the "latest" record (based on timestamp) for each "unique" server. So for example my main table looks like this
... (3 Replies)
Discussion started by: hcclnoodles
3 Replies
3. Web Development
hello all
i have 2 columns every column in the following format
column1
2011-04-01 11:39:54
column2
2019-02-03 00:00:00
i want get difference between above data as following
2 days 11:39
how to do so ?
i tried many functions but nothing works
please advice what is the query... (6 Replies)
Discussion started by: mogabr
6 Replies
4. Shell Programming and Scripting
Hi,
I want to access mysql query from database , for that i have tried the below code
#! /bin/bash
TABLE_NAME=database1
USER_NAME=root
IP_ADDR=111.20.9.256
somevar=`echo "select altid from alert where altid='2724'"| mysql -h $IP_ADDR -u $USER_NAME $TABLE_NAME `
echo $somevar
... (1 Reply)
Discussion started by: aish11
1 Replies
5. Programming
Hi,
I want to run below query on shellscript but having one problm.
ADV=$( mysql -h "$IP_ADDR" -u "$USER_NAME" "$TABLE_NAME" -BNe" SELECT ADV FROM indata where inid='$INSTRUID' and Date='$latest Date';" )
here Date column contans different below dates
2011-12-01... (0 Replies)
Discussion started by: aish11
0 Replies
6. Shell Programming and Scripting
Hi,
I want to run below query on shellscript but having one problm.
ADV=$( mysql -h "$IP_ADDR" -u "$USER_NAME" "$TABLE_NAME" -BNe" SELECT ADV FROM indata where inid='$INSTRUID' and Date='$latest Date';" )
here Date column contans different below dates
2011-12-01... (11 Replies)
Discussion started by: aish11
11 Replies
7. Programming
Hello
i have created mysql query to compare to values and get difference in percentage
as following:
SELECT file_name, 100 - ((100 * (SELECT file_count FROM xipi_files z WHERE x.file_group = z.file_group AND x.file_name = z.file_name AND z.insert_date = CURDATE( ) - INTERVAL 1 DAY)) /... (1 Reply)
Discussion started by: mogabr
1 Replies
8. Programming
Hi All,
i have a table in mysql with the following data
Table name Test
Assettype Serial_No Status location
Mouse 123456 In Stock chennai
Mouse 98765 Allocated chennai
Keyboard ... (2 Replies)
Discussion started by: venkitesh
2 Replies
LEARN ABOUT PHP
mysql_db_query
MYSQL_DB_QUERY(3) 1 MYSQL_DB_QUERY(3)
mysql_db_query - Selects a database and executes a query on it
SYNOPSIS
Warning
This function was deprecated in PHP 5.3.0, and will be removed in the future, along with the entirety of the original MySQL exten-
sion. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more
information. Alternatives to this function include:
omysqli_select_db(3) then the query
o PDO::__construct
resource mysql_db_query (string $database, string $query, [resource $link_identifier = NULL])
DESCRIPTION
mysql_db_query(3) selects a database, and executes a query on it.
o $database
- The name of the database that will be selected.
o $query
- The MySQL query. Data inside the query should be properly escaped.
o $
link_identifier -The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect(3) is
assumed. If no such link is found, it will try to create one as if mysql_connect(3) was called with no arguments. If no connection
is found or established, an E_WARNING level error is generated.
Returns a positive MySQL result resource to the query result, or FALSE on error. The function also returns TRUE/ FALSE for INSERT/ UPDATE/
DELETE queries to indicate success/failure.
+--------+---------------------------------------------------+
|Version | |
| | |
| | Description |
| | |
+--------+---------------------------------------------------+
| 5.3.0 | |
| | |
| | This function now throws an E_DEPRECATED notice. |
| | |
+--------+---------------------------------------------------+
Example #1
mysql_db_query(3) alternative example
<?php
if (!$link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password')) {
echo 'Could not connect to mysql';
exit;
}
if (!mysql_select_db('mysql_dbname', $link)) {
echo 'Could not select database';
exit;
}
$sql = 'SELECT foo FROM bar WHERE id = 42';
$result = mysql_query($sql, $link);
if (!$result) {
echo "DB Error, could not query the database
";
echo 'MySQL Error: ' . mysql_error();
exit;
}
while ($row = mysql_fetch_assoc($result)) {
echo $row['foo'];
}
mysql_free_result($result);
?>
Note
Be aware that this function does NOT switch back to the database you were connected before. In other words, you can't use this
function to temporarily run a sql query on another database, you would have to manually switch back. Users are strongly encouraged
to use the database.table syntax in their sql queries or mysql_select_db(3) instead of this function.
mysql_query(3), mysql_select_db(3).
PHP Documentation Group MYSQL_DB_QUERY(3)