How to delete a record from mysql which are having the given id

Question

Now i have the table like

--------------------------
merge_id  |  merge_combo |
--------------------------
A1        |   25,9       |
A2        |   25,21      |
A3        |   2,5,15     |
A4        |   2,9,5      |
A5        |   12,19,2    |
A6        |   2,1        |
--------------------------

for example now if i pass the value 9, then it should check the merge_combo and delete the rows which are having 9 (A1,A4 this two having 9)

Answer 1

You can do this with find_in_set() :

delete from tbl
    where find_in_set(9, merge_combo) > 0;

The bigger issue is that you are storing numbers in a string for a list. SQL has this great data structure for storing lists -- it is called a table. In this case, you want a junction table, with one row per merge_id and combo item.

Answer 2

DELETE from your_table where FIND_IN_SET(9, merge_combo) or merge_combo IN(9)

Answer 3

您可以使用以下qry

DELETE FROM tbl WHERE merge_combo LIKE '%,9,%' OR merge_combo LIKE '9,%' OR merge_combo LIKE '%,9' OR merge_combo = '9';

Answer 4

You may use Find_In_Set

delete from your_table where FIND_IN_SET(@val, merge_combo)

FIND_IN_SET(str,strlist)

Returns a value in the range of 1 to N if the string str is in the string list strlist consisting of N substrings. A string list is a string composed of substrings separated by “,” characters. If the first argument is a constant string and the second is a column of type SET, the FIND_IN_SET() function is optimized to use bit arithmetic. Returns 0 if str is not in strlist or if strlist is the empty string. Returns NULL if either argument is NULL. This function does not work properly if the first argument contains a comma (“,”) character.

Answer 5

使用以下查询

DELETE FROM tbl WHERE FIND_IN_SET("9",merge_combo)

Answer 6

You should not create a complex SQL query with LIKE .If you have a bad db design your app will be bad too.

Instead normalize your database that comes up even against the 1NF. Try to break merge_combo to merge_comboA and merge_comboB and merge_comboC if you know that you will have to untill 3 combo values or for the best implementation create a separate table with composite keys (this way you will avoid Null values)

PS : use the queries proposed only if you can't change your database (eg an academic exercise to test your knoweledge on queries)

Answer 7

Connection:

$mysqli = new mysqli ('localhost', 'admin_user', 'Paradise1191', 'admin_db');

if (mysqli_connect_errno()) {
    printf("Connect failed: %s\n", mysqli_connect_error());
    exit();
}

$mysqli->set_charset("utf8");

Select & Delete:

$var = "Your Result";
$array = array();

$query = "SELECT * FROM `TABLE` WHERE 1";

if ($result = $mysqli->query($query)) {

while ($row = $result->fetch_array())
{
    $this_id = $row['merge_id'];
    $var1 = $row['merge_combo'];
    $array = explode(",",$var1 );
    if (in_array($var, $people)) {

    $query = "DELETE FROM `TABLE` WHERE `merge_id` = '$this_id'";
    $mysqli->query($query);        

    }

}
$result->close();
}

Answer 8

您应该尝试以下查询：

DELETE FROM merge WHERE merge_combo LIKE '% 9 %';