I have a database similar to this:
table name = jos_school ... id = Primary key, name = Unique key
id name no_of_students no_of_staffs fees
1 schoolA 0 0 0
2 schoolB 0 0 0
...
...
In phpMyAdmin I did something like this, and it worked (successfully updated multiple rows and columns),
UPDATE jos_school
SET no_of_students = CASE name
WHEN 'schoolA' THEN '1523'
WHEN 'schoolB' THEN '546'
....
END,
no_of_staffs = CASE name
WHEN 'schoolA' THEN '1234'
WHEN 'schoolB' THEN '346'
....
END
WHERE name IN ('schoolA', 'schoolB')
However, I was not able to update the table USING JOOMLA's Update methods. I don't want to use foreach and update the table over 1000 times. I want to execute a single query.
I've also read: http://docs.joomla.org/Inserting,_Updating_and_Removing_data_using_JDatabase#Updating_a_Record
and dint found it helpful in this case.
So, can someone point me to the right direction.
You can query as below,
// Create a new query object.
$db = &JFactory::getDBO();
$query = $db->getQuery(true);
// Select the required fields from the table.
$query="UPDATE jos_school SET no_of_students = CASE name";
foreach($data as $d)
{
$query.=".....";
}
$query.=".....";
$db->setQuery((string)$query);
Hope that helps ...
Related
I want my the id field in my table to be a bit more " random" then consecutive numbers.
Is there a way to insert something into the id field, like a +9, which will tell the db to take the current auto_increment value and add 9 to it?
Though this is generally used to solve replication issues, you can set an increment value for auto_increment:
auto_increment_increment
Since that is both a session and a global setting, you could simply set the session variable just prior to the insert.
Besides that, you can manually do it by getting the current value with MAX() then add any number you want and insert that value. MySQL will let you know if you try to insert a duplicate value.
You have a design flaw. Leave the auto increment alone and shuffle your query result (when you fetch your data)
As far as i know, it's not possible to 'shuffle' your current IDs. If you wanted though, you could pursue non-linear IDs in the future.
The following is written in PDO, there are mysqli equivalents.
This is just an arbitrary INSERT statement
$name = "Jack";
$conn = new PDO("mysql:host=$dbhost;dbname=$dbname",$dbuser,$dbpass);
$sql = "INSERT INTO tableName (name) VALUES(:name)";
$q = $conn->prepare($sql);
$q->execute(':name' => $name);
Next, we use lastInsertId() to return the ID of the last inserted row, then we concatenate the result to rand()
$lastID = $conn->lastInsertId();
$randomizer = $lastID.rand();
Finally, we use our 'shuffled' ID and UPDATE the previously inserted record.
$sql = "UPDATE tableName SET ID = :randomizer WHERE ID=:lastID ";
$q = $conn->prepare($sql);
$q->execute(array(':lastID' => $lastID , ':randomizer' => $randomizer));
An idea.. (Not tested)
CREATE TRIGGER 'updateMyAutoIncrement'
BEFORE INSERT
ON 'DatabaseName'.'TableName'
FOR EACH ROW
BEGIN
DECLARE aTmpValueHolder INT DEFAULT 0;
SELECT AUTO_INCREMENT INTO aTmpValueHolder
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = 'DatabaseName'
AND TABLE_NAME = 'TableName';
SET NEW.idColumnName =aTmpValueHolder + 9;
END;
Edit : If the above trigger doesn't work try to update AUTO_INCREMENT value directly into the system's schema. But as noted by Eric, your design seems to be flawed. I don't see the point of having an auto-increment here.
Edit 2 : For a more 'random' and less linear number.
SET NEW.idColumnName =aTmpValueHolder + RAND(10);
Edit 3 : As pointed out by Jack Williams, Rand() produces a float value between 0 and 1.
So instead, to produce an integer, we need to use a floor function to transform the 'random' float into an integer.
SET NEW.idColumnName =aTmpValueHolder + FLOOR(a + RAND() * (b - a));
where a and b are the range of the random number.
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
I am trying to insert records in 2 different mysql tables. Here's the situation:
Table 1: is_main that contains records of resorts with a primary key called id.
Table 2: is_features that contains a list of features that a resort can have (i.e. beach, ski, spa etc...). Each feature has got a primary key called id.
Table 3: is_i2f to connect each resort id with the feature id. This table has got 2 fields: id_i and id_f. Both fields are primary key.
I have created a form to insert a new resort, but I'm stuck here. I need a proper mysql query to insert a new resort in the is_main table and insert in is_i2f one record for each feature it has, with the id of the resort id id_i and the id of the feature id id_f.
$features = ['beach','relax','city_break','theme_park','ski','spa','views','fine_dining','golf'];
mysql_query("INSERT INTO is_main (inv_name, armchair, holiday, sipp, resort, price, rooms, inv_length, more_info)
VALUES ('$name', '$armchair', '$holiday', '$sipp', '$resort', '$price', '$rooms', '$length', '$more_info')");
$id = mysql_insert_id();
foreach($features as $feature) {
if(isset($_POST[$feature])) {
$$feature = 1;
mysql_query("INSERT INTO is_i2f (id_i, id_f) VALUES (" . $id . ", ?????????????? /missing part here????/ ); }
else {
$$feature = 0; }
}
Thanks.
Please, I'm going CrAzY!!!!!!!!!!!!!!
This may not be relevant to you, but...
Would it not make more sense to leave the link table unpopulated? You can use JOINs to then select what you need to populate the various views etc in your application
i.e. query to get 1 resort with all features:
SELECT
Id,
f.Id,
f.Name
FROM IS_MAIN m
CROSS JOIN IS_FEATURES f
WHERE m.Id = $RequiredResortId
Please find the answer on Mysql insert into 2 tables.
If you want to do multiple insert at a time you can write a SP to fulfill your needs
If I understand you correctly you could concatenate variable amount of to be inserted/selected values into one query. (This is the second query which needs an id from the first.)
//initializing variables
$id = mysql_insert_id();
$qTail = '';
$i = -1;
//standard beginning
$qHead = "INSERT INTO `is_i2f` (`id`,`feature`) VALUES ";
//loop through variable amount of variables
foreach($features] as $key => $feature) {
$i++;
//id stays the same, $feature varies
$qValues[$i] = "('{$id}', '{$feature}')";
//multiple values into one string
$qTail .= $qValues[$i] . ',';
} //end of foreach
//concatenate working query, need to remove last comma from $qTail
$q = $qHead . rtrim($qTail, ',');
Now you should have a usable insert query $q. Just echo it and see how it looks and test if it works.
Hope this was the case. If not, sorry...
"BIG" UPDATE:
Ok I was getting the whole
auto-increment point wrong. I though
this would be an easier way to target
the first, second, third and so row,
but it is just the wrong approach.
You should instead care about that the
auto_increments are unique and well...
that they increment. You should use
the for that.
I wont delete this question because I
think it might be helpful for someone
else with the same wrong idea, BUT
BE WARNED! :)
I have a very simple MySQL table which went like this:
id comment user
1 hello name1
2 bye name2
3 hola name3
Then I deleted the two first comments, the result:
id comment user
3 hola name3
So now when I add comments:
id comment user
3 hola name3
5 chau name4
6 xxx name5
My problem is that I would need that whenever a row gets deleted it should "start over" and look like this.
id comment user
1 hola name3
2 chau name4
3 xxx name5
I would like to know how is it possible to some how "restart" the table so that it is "always" indexed 1, 2, 3 and so on.
Thanks in advance!!
I hope I have explained myself clear enough, I'm sorry for all my "plain english", feel free to edit if you think a word might be confusing :) and please ask for any clarification needed!
BTW: I did not add any of my code because this is a simplified situation and I though it be more confusing and less helpful to others, but I you think it would help (or is necessary) tell me about it!
Assuming there are no foreign key issues to deal with, this code will do it:
set #id:=0;
update mytable
set id = (#id := #id + 1)
order by id;
If there are foreign key issues, make sure your constraints are defined like this before you execute the update:
ALTER CHILD_TABLE ADD CONSTRAINT
FOREIGN KEY MYTABLE_ID REFERENCES MYTABLE
ON UPDATE CASCADE; -- This is the important bit
When it's all done, execute this to fix up the auto_increment value:
SELECT MAX(ID) + 1 FROM MYTABLE; -- note the output
ALTER TABLE MYTABLE AUTO_INCREMENT = <result from above>;
Disclaimer: I can't think of one valid reason to do this, and it can break stuff very bad. However, I'm adding this for the sake of completeness and demonstration purposes.
You could use this really ugly solution, please only do this if you're at gunpoint or your dog is held hostage!
-- Create a new veriable.
SET #newId:=0;
-- Set all id's in the table to a new one and
-- also increment the counter in the same step.
-- It's basically just setting id to ++id.
UPDATE
yourTableHere
SET
id=#newId:=#newId+1;
-- Now prepare and execute an ALTER TABLE statement
-- which sets the next auto-increment value.
SET #query:=CONCAT("ALTER TABLE yourTableHere AUTO_INCREMENT=", #newId+1);
PREPARE sttmnt FROM #query;
EXECUTE sttmnt;
DEALLOCATE PREPARE sttmnt;
This will reset all of the Ids to the position of the row in the table. Please be aware that this will reorder the rows to how MySQL gets them from the storage engine, so there's no guarantee on the order in any way.
If you have a system which is based on the Ids (like relationships between tables) then you'll be...well, let's say I hope you have a backup.
Can't be done using MySQL's autoincrement feature. You could roll your own solution, e.g. a mix between application logic and database triggers. BUT, seriosly, your design is heavily broken if it requires you to recycle UNIQUE IDs.
Couldn't you just create another table where you'd save references like that (this could be done by querying the minimum) and let your main table point to that auxilliary table?
EDIT
Here's a blog I've googled that deals with your problem: see here.
ALTER TABLE event AUTO_INCREMENT = 1;
That's not the purpose of AUTO_INCREMENT. It exists to generate unique identifiers, not to maintain a gapless sequence.
If you have a valid reason for wanting this, then generate the identifiers yourself in your code. AUTO_INCREMENT won't provide this for you.
Accentually, auto increment is made for that to increase, no matter, how much rows are there.
ALTER TABLE table AUTO_INCREMENT = 1 does reseting, but you may get some bad things, if ID's starts to repeating.
So, my advise would be - leave it alone :)
function backup_tables($host, $user, $pass, $dbname, $tables = '*'){
$connect = mysqli_connect($host, $user, $pass , $dbname);
mysqli_query($connect, "SET NAMES 'utf8'");
//get all of the tables
if($tables == '*'){
$tables = array();
$result = mysqli_query($connect, 'SHOW TABLES');
while($row = mysqli_fetch_row($result))
{
$tables[] = $row[0];
}
}
else
{
$tables = is_array($tables) ? $tables : explode(',',$tables);
}
foreach($tables as $table){
$table = trim($table);
// getting all table fields
$tblDetails = mysqli_query($connect,"SHOW FULL COLUMNS FROM $table");
// we may need to know how to create our table
$tblCreate = mysqli_fetch_row(mysqli_query($connect, 'SHOW CREATE TABLE '.$table));
// getting last line from table creation script in order to get info about engine ->suffix1
$suffix1 = end(explode(PHP_EOL,$tblCreate[1]));
// if there is auto increment we have to remove
if (strpos($suffix1,"AUTO_INCREMENT")){
$tmpArr = explode(" ",$suffix1);
$newStr = '';
foreach ($tmpArr as $term){
if (!is_int(strpos($term, "AUTO_INCREMENT"))) $newStr .= $term . ' '; else $suffix4 = $term; // suffix4 stores next value of auto_increment
}
$suffix1 = $newStr;
} // now if there is auto_increment we removed from the last line of creation table script
$return .= "DROP TABLE IF EXISTS `".$table."` CASCADE;\n\n";
// starting creation table with our rules
$kgbReturn = "CREATE TABLE `$table` (\n";
while($cols = mysqli_fetch_row($tblDetails )){
if ($cols[2]) $cols[2] = " COLLATE " . $cols[2]; //if a charset defined add to line
if ($cols[3]=='NO') $cols[3] = " NOT NULL"; // if the field may be null
$kgbReturn .= "`".$cols[0]."` ".$cols[1]. $cols[2] . $cols[3]. ",\n"; //field creation line ready
}
$kgbReturn = rtrim($kgbReturn,",\n") . "\n" .trim($suffix1," ") . ";\n\n"; // table creation without auto_increment
$tblDetails = mysqli_query($connect,"SHOW FULL COLUMNS FROM $table WHERE (`Key` LIKE 'PRI%')");
$suffix2 = '';
while($cols = mysqli_fetch_row($tblDetails )){
$suffix2 .= "ALTER TABLE `". $table ."` \n ADD PRIMARY KEY (`".$cols[0]."`);\n\n";
}
$tblDetails = mysqli_query($connect,"SHOW FULL COLUMNS FROM $table WHERE (Extra LIKE 'auto_increment%')");
$suffix3 = '';
while($cols = mysqli_fetch_row($tblDetails )){
$suffix3 = "ALTER TABLE `". $table ."` \n ADD PRIMARY KEY (`".$cols[0]."`);\n\n";
$suffix3 = "ALTER TABLE `".$table."` \n MODIFY `".$cols[0]."` ".$cols[1]." NOT NULL AUTO_INCREMENT, ".$suffix4.";";
}
$return .= $kgbReturn;
$result = mysqli_query($connect, 'SELECT * FROM '.$table);
$num_fields = mysqli_num_fields($result);
// insert into all values
for ($i = 0; $i < $num_fields; $i++){
while($row = mysqli_fetch_row($result)){
$return .= 'INSERT INTO '.$table.' VALUES(';
for($j=0; $j < $num_fields; $j++){
$row[$j] = addslashes($row[$j]);
$row[$j] = str_replace (array("\r\n", "\n", "\r", PHP_EOL), '\r', $row[$j])
;
if (isset($row[$j])) { $return.= '"'.$row[$j].'"' ; } else { $return .= '""'; }
if ($j < ($num_fields-1)) { $return .= ','; };
}
$return .= ");\n";
}
}
$return .= "\n\n"; // insert values completed.
// now add primary key and auto increment statements if exist
$return .= $suffix2 . $suffix3 . "\n\n\n";
echo "<pre>".$return ."</pre>"; // debug line. comment if you don't like.
}
// we need to write to a file that coded as utf-8
$bkTime = date('Y_m_j_H_i_s');
$fileName = 'backup-db-'.$bkTime.'.sql';
$f=fopen($fileName,"w");
# Now UTF-8 - Add byte order mark
fwrite($f, pack("CCC",0xef,0xbb,0xbf));
fwrite($f,$return);
fclose($f);
}
You shouldn't really be worrying about this - the only thing an id should be is unique; its actual value should be irrelevant.
That said, here is a way (see the top comment) to do exactly what you want to do.
For those that are looking to "reset" the auto_increment, say on a list that has had a few deletions and you want to renumber everything, you can do the following.
DROP the field you are auto_incrementing.
ALTER the table to ADD the field again with the same attributes.
You will notice that all existing rows are renumbered and the next auto_increment number will be equal to the row count plus 1.
(Keep in mind that DROPping that column will remove all existing data, so if you have exterior resources that rely on that data, or the numbers that are already there, you may break the link. Also, as with any major structure change, it's a good idea to backup your table BEFORE you make the change.)
Maybe it is your approach to the solution you're trying to achieve that is not correct as what you're trying to achieve it's not possible "automatically" and doing by hand when you have thousands of rows will make your system lag.
Is it really necessary that it the system adjusts at every delete?
update table_name set id =NULL; alter table table_name change column
`id` `id` int auto_increment;
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);
}