I have a query here. I wanted to delete my data in my browser table but I dont want it to be deleted permanently, I just want it to be hidden. My problem is I don't know what kind of query will I be needing. Here is my delete query.
My table feilds are Id Name and Flag. I want to do is when the flag is 1 it shows up the table and if it is 0 it will be hidden when the delete button is pressed.
function delete()
{
$id = $this->input->get('id');
$sSQL = "DELETE FROM tableq where id = ?";
$this->db->query($sSQL, array($id));
}
You can just update the flag, and in your select query select only flag=1 Try this,
$sSQL = "update tableq set `flag` =0 where id = ?";
$this->db->query($sSQL, array($id));
Related
I want to update the last row in a mysql table
UPDATE logend
SET endsecs = endsecs+'$moretime'
WHERE id = (SELECT id FROM logend ORDER BY id DESC LIMIT 1)
But it doesn't work, because of this error:
ERROR 1093 (HY000): You can't specify target table 'logend' for update in FROM clause
In MySql you can't use the updated table in a subquery the way you do it.
You would get the error:
You can't specify target table 'logend' for update in FROM clause
What you can do is an UPDATE with ORDER BY and LIMIT:
$sql = "UPDATE logend SET endsecs=endsecs+'$moretime' ORDER BY id DESC LIMIT 1";
Can't you just get the max(id) and update that?
$sql = "UPDATE logend SET endsecs=endsecs+'$moretime' WHERE id = (
SELECT id FROM (
SELECT MAX(id) FROM logend) AS id
)";
Here's another solution: a self-join, to find the row for which no other row has a greater id.
Also, you should really not interpolate POST inputs directly into your SQL statement, because that exposes you to SQL injection problems. Use a query parameter instead.
$moretime = $_POST['moretime'];
$sql = "
UPDATE logend AS l1
LEFT OUTER JOIN logend AS l2 ON l1.id < l2.id
SET l1.endsecs = l1.endsecs + ?
WHERE l2.id IS NULL";
$stmt = $mysqli->prepare($sql);
if (!$stmt) {
trigger_error($mysqli->error);
die($mysqli->error);
}
$stmt->bind_param("s", $moretime);
$ok = $stmt->execute();
if (!$ok) {
trigger_error($stmt->error);
die($stmt->error);
}
I want to update multiple itemIDs with the same status. I know that this is imposible with mysql_query but I can't figure out a way to get this working.
$upd = "UPDATE booking SET status='$status' WHERE itemID='$itemID', '$itemID2'";
$retval = mysql_query($upd, $con);
Note: The itemIDs are inputted by user in prev page like this
$itemID= $_POST["itemID"];
$itemID2= $_POST["itemID2"];
Use IN clause as like:
WHERE itemId in ('$itemID', '$itemID2');
instead of WHERE itemID='$itemID', '$itemID2'
Use IN
$upd = "UPDATE booking SET status='$status' WHERE itemID IN ('$itemID', '$itemID2')";
How can I change this SQL to do the following:
If user is not in table, add them. [THIS PART WORKS]
If user IS in table AND favourite_active = 0 change it to favourite_active = 1.
If user is in table AND favourite_active = 1 change it to favourite_active = 0.
I need to add in WHERE clauses I think.
$result = mysql_query("SELECT * FROM tbl_favourites WHERE (user_id = '$who' AND favourite_id = '$usernum' AND favourite_active = '1')");
// if user does not exist in favourites, add them
if(mysql_num_rows($result) == 0)
{
mysql_query("INSERT INTO tbl_favourites (user_id, favourite_id, favourite_active) VALUES ('$who', '$usernum', '1')");
echo"You have added this user as a favourite";
}
// if user does exist and favourite_active = 1 change to 0
else {
mysql_query("UPDATE tbl_favourites SET favourite_active='0' WHERE user_id='$who' AND favourite_id='$usernum'");
echo"You have removed this user as a favourite";
}
// if user does NOT exist and favourite_active = 0 change to 1
else {
mysql_query("UPDATE tbl_favourites SET favourite_active='1' WHERE user_id='$who' AND favourite_id='$usernum'");
echo"You have removed this user as a favourite";
}
You can't have two else clauses in an IF. And you can't do the UPDATE in two separate queries, because the second one will simply undo the first one. Use the following query:
UPDATE tbl_favourites SET favourite_active = NOT favourite_active WHERE user_id = '$who' and `favourite_id = '$usernum'
I'm also not sure that the first part, which you say works, really works. Your SELECT query looks specifically for favourite_active = 1. If the user already exists with favourite_active = 0, you'll try to INSERT them. Is that really what you want? Maybe you should remove AND favourite_active = '1'.
If user_id and favourite_id form a unique index on the table, you can do the entire thing in a single query:
INSERT INTO tbl_favourites (user_id, favourite_id, favourite_active)
VALUES ('$who', '$usernum', '1')
ON DUPLICATE KEY UPDATE favourite_active = NOT favourite_active
Although there are many questions similar to this, such as
"Updating a record from another table", but i could not get this working.
I have a query that selects and updates table sem_stdexamfinresmark. The select subquery returns multiple rows of data whose size may not be equal to the table being updated, but the update is now working.
The query looks like :
update sem_stdexamfinresmark sr,
(select
se.currsession,
str.studentid,
str.classid,
str.subjectid,
str.aggScore*(select gbtp.percentage from gb_termpercentage gbtp where gbtp.termname = se.examtype)/100 as aggPer,
str.aggGrade
from
sem_stdexamtermresr str,
sem_exam se
where
str.examid=se.examid and
se.examtype = 'Second Term' and
se.currsession =1 and classid='8'
) s
set
sr.SecondTermMark = s.aggPer and
sr.SecondTermGrade = s.aggGrade
where
sr.studentid=s.studentid and
sr.subjectid=s.subjectid and
s.currsession = s.currsession and
sr.classid='8';
EDIT:
update sem_stdexamfinresmark
set
sr.SecondTermMark = s.aggPer and
sr.SecondTermGrade = s.aggGrade
from
(select
se.currsession,
str.studentid,
str.classid,
str.subjectid,
str.aggScore*(select gbtp.percentage from gb_termpercentage gbtp where gbtp.termname = se.examtype)/100 as aggPer,
str.aggGrade
from
sem_stdexamtermresr str,
sem_exam se
where
str.examid=se.examid and
se.examtype = 'Second Term' and
se.currsession = 1 and classid='8'
) s
where
sr.studentid=s.studentid and
sr.subjectid=s.subjectid and
s.currsession =1 and
sr.classid='8';
select * from sem_exam;
update sem_exam set currsession =1;
try something that looks more like:
update foo
set col = bar.col
from bar
where ...
This is what happens when one loses sleep :( I just did a silly mistake here and added "and"
I have a table with 27 varchar fields. I want to make all fields lowercase, but i want to do it in one short mysql call.
This does a single field:
UPDATE table
SET field = LOWER(field)
How do I do the equivalent of this (which doesn't work):
UPDATE table
SET * = LOWER(*)
You can't do it with your creative attempt SET * = LOWER(*) etc.
You can however do it like this:
UPDATE table SET
column1 = LOWER(column1),
column2 = LOWER(column2),
-- etc, listing all text type columns
columnN = LOWER(columnN);
The reason there's no "shortcut" is probably because this pattern is so infrequently needed.
The consensus is that this cannot be done in a single mysql query.
Here is a super quick PHP script that does this for N fields (thanks for the idea #alex):
$sql = "SHOW COLUMNS
FROM table";
$results = mysqli_query($dbcon,$sql);
while($column = mysqli_fetch_assoc($results))
{
$column = $column["Field"];
$sql = "UPDATE table
SET $column = LOWER($column)";
$success = mysqli_query($dbcon,$sql);
}