How to retrieve items in a manually-specified order - mysql

I have a list of id's in PHP. For example:
$id = (4,6,3,2,5,1)
When I perform a query like this:
$query = mysql_query("SELECT * FROM table WHERE ID IN ($id)");
it retrieves the results I want but the items are returned in the insertion order.
Instead, I want to retrieve the results in the order given in my array:
information 4, information 6, information 3, information 2, information 5, information 1
How can I do that?
Thanks guys! solution is ORDER BY FIELD (ID, $id);

Try this
$query = "SELECT * FROM table WHERE ID IN ($id) ORDER BY FIELD(ID,$id) ";
you can see this http://marco-pivetta.com/mysql-custom-sorting-rule-mysql/

$query = "SELECT * FROM table WHERE ID IN ($id) ORDER BY ";
foreach ($id as $i) {
$query .= "ID = $i,";
}
$query = mysql_query(rtrim($query, ','));
Your code is vulnerable to injection. You should use properly parameterized queries with PDO or mysqli.

You can use FIELD on this,
SELECT *
FROM table
WHERE ID IN (4,6,3,2,5,1)
ORDER BY FIELD(ID, 4,6,3,2,5,1)
Custom Sorting using FIELD() example

$query="SELECT * FROM table WHERE ID IN ($id) ORDER BY FIND_IN_SET(ID,$id) DESC";
Also check this
Select query using IN() and without any sorting

Related

Codeigniter - how to delete row on inner join? [duplicate]

I have a problem with my query and I need to join two tables from different databases now my problem is how can I execute my query. I got my syntax format from here
Please visit first this link so you could understand why my SQL syntax is like this http://www.x-developer.com/php-scripts/sql-connecting-multiple-databases-in-a-single-query
Im using CodeIgniter and here is an Idea of what my query looks like: Notice the way I'm selecting my columns: DATABASE_NAME.TABLE_NAME.COLUMN_NAME
$ENROLLEES = $this->load->database('ENROLLEES', TRUE);
$ACCOUNTS = $this->load->database('ACCOUNTS', TRUE);
$SELECT = "SELECT $ACCOUNTS.BALANCES_TABLE.IDNO, $ACCOUNTS.BALANCES_TABLE.balance";
$FROM = "FROM $ACCOUNTS.BALANCES_TABLE";
$WHERE = "$ACCOUNTS.BALANCES_TABLE.IDNO IN (SELECT $ENROLLEES.ENROLLEES_TABLE.IDNO FROM $ENROLLEES.ENROLLEES_TABLE)";
$SQL = $SELECT ." ". $FROM ." ". $WHERE;
MAIN PROBLEM: How to Execute my query?
If we do like this in codeIgniter:
$ENROLLEES->query($SQL); or $ACCOUNTS->query($SQL);
How can I execute my query that Im having multiple databases? What will I provide here[database]->query($SQL); ?
$sql="Select * from my_table where 1";
$query = $this->db->query($SQL);
return $query->result_array();
If the databases share server, have a login that has priveleges to both of the databases, and simply have a query run similiar to:
$query = $this->db->query("
SELECT t1.*, t2.id
FROM `database1`.`table1` AS t1, `database2`.`table2` AS t2
");
Otherwise I think you might have to run the 2 queries separately and fix the logic afterwards.
I can see what #Þaw mentioned :
$ENROLLEES = $this->load->database('ENROLLEES', TRUE);
$ACCOUNTS = $this->load->database('ACCOUNTS', TRUE);
CodeIgniter supports multiple databases. You need to keep both database reference in separate variable as you did above. So far you are right/correct.
Next you need to use them as below:
$ENROLLEES->query();
$ENROLLEES->result();
and
$ACCOUNTS->query();
$ACCOUNTS->result();
Instead of using
$this->db->query();
$this->db->result();
See this for reference:
http://ellislab.com/codeigniter/user-guide/database/connecting.html
http://www.bsourcecode.com/codeigniter/codeigniter-select-query/
$query = $this->db->query("select * from tbl_user");
OR
$query = $this->db->select("*");
$this->db->from('table_name');
$query=$this->db->get();
return $this->db->select('(CASE
enter code hereWHEN orderdetails.ProductID = 0 THEN dealmaster.deal_name
WHEN orderdetails.DealID = 0 THEN products.name
END) as product_name')
$this->db->select('id, name, price, author, category, language, ISBN, publish_date');
$this->db->from('tbl_books');

MySQL query involving multiple rows, access one based on max value

So I am trying to have a single script that accesses all values of a table based on a particular id. The script returns the values in an array using PHP:
Example:
// Select data from DB
$query = 'SELECT * FROM experiences WHERE user_id = ' . $id;
$result = mysqli_query($link, $query) or die (mysqli_error($link));
// Not sure this actually creates a 2D array...
$array = mysqli_fetch_array($result);
However, I realize that I need modified results for particular tasks, such as the row where a particular value is the highest.
How would I go about doing this, and does $array actually hold all the rows and respective fields?
TRY
'SELECT * FROM experiences WHERE user_id ='.$id.' HAVING MAX(column_name)
OR
"SELECT max(column_name), other column...
FROM experiences
WHERE user_id =".(int)$id
Assuming you have cleaned $id properly you can do this
// Select data from DB
$query = 'SELECT * FROM experiences WHERE user_id = ' . $id;
$result = mysqli_query($link, $query) or die (mysqli_error($link));
$data = array();
while($row = mysqli_fetch_array($result)) {
$data[] = $row;
}
and $data will contain the 2D array you're looking for.
If you want the row where a particular value is highest I suggest either looking into ORDER BY or MAX() depending on your needs.

Can you have an OR in a WHERE statement inside a mysql query?

Is it possible to have an OR inside a WHERE statement in a mysql query as I have done below.
$query = mysql_query("SELECT * FROM fields WHERE post_id=$id OR post_id="" order by id desc") or die(mysql_error());
This produces a server error when run on my site. Any thoughts on how I could accomplish this?
Thanks in advance.
Yes you can have an OR. What is the type of post_id?
If post_id is a character type:
"SELECT * FROM fields WHERE post_id='$id' OR post_id='' order by id desc"
If it's an integer then it can't be equal to the empty string. Did you mean post_id IS NULL instead?
What is the error? It looks like you have not escaped the double quote in the query. It should be:
$query = mysql_query("SELECT * FROM fields WHERE post_id=$id OR post_id=\"\" order by id desc") or die(mysql_error());
what are the errors.. as such ur query is fine but u string problems with all these double quotes.. try something like this..
$query = mysql_query("SELECT * FROM fields
WHERE post_id = " . $id . " OR post_id='' order by id desc")
or die(mysql_error());

MySql SHOW query in ZEND

In zend it is written like
$table = $this->getTable();
$select = $table->select()->where('status = ?',1)
->where('columnOne= ?', 1)
->order('columnTwo')
->limit(1);
similar to where, order, limit conditions how can I condition for LIKE?
My query is
SHOW TABLE STATUS LIKE 'tableName'
I tried in this way
$table = $this->getTable();
$query= $table->select("TABLE STATUS")
->like($table);
$id = mysql_query($query);
then I found that no method for LIKE is available in ZEND.
Then How can I write above query in Zend framerk?
Thanks in advance.
This works for me, so hopefully it should give you what you want:
$stmt = $dbAdapter->query("SHOW TABLE STATUS LIKE '$tableName';");
$tableStatus = $stmt->fetchObject();

Zend_Db: How to get the number of rows from a table?

I want to find out how many rows are in a table. The database that I am using is a MySQL database. I already have a Db_Table class that I am using for calls like fetchAll(). But I don't need any information from the table, just the row count. How can I get a count of all the rows in the table without calling fetchAll()?
$count = $db->fetchOne( 'SELECT COUNT(*) AS count FROM yourTable' );
Counting rows with fetchAll considered harmful.
Here's how to do it the Zend_Db_Select way:
$habits_table = new Habits(); /* #var $habits_table Zend_Db_Table_Abstract */
$select = $habits_table->select();
$select->from($habits_table->info(Habits::NAME), 'count(*) as COUNT');
$result = $habits_table->fetchRow($select);
print_r($result['COUNT']);die;
Proper Zend-Way is to use Zend_Db_Select like this:
$sql = $table->select()->columns(array('name', 'email', 'status'))->where('status = 1')->order('name');
$data = $table->fetchAll($sql);
$sql->reset('columns')->columns(new Zend_Db_Expr('COUNT(*)'));
$count = $table->getAdapter()->fetchOne($sql);
This is how it's done in Zend_Paginator. Other option is to add SQL_CALC_FOUND_ROWS before your column list and then get the number of found rows with this query:
$count = $this->getAdapter()->fetchOne('SELECT FOUND_ROWS()');
You could do a
SELECT COUNT(*)
FROM your_table
$dbo->setFetchMode( Zend_Db::FETCH_OBJ );
$sql = 'SELECT COUNT(*) AS count FROM #table';
$res = $dbo->fetchAll( $sql );
// $res[0]->count contains the number of rows
I'm kind of a minimalist:
public function count()
{
$rows = $db->select()->from($db, 'count(*) as amt')->query()->fetchAll();
return($rows[0]['amt']);
}
Can be used generically on all tables.
Add count capability to your Zend_DB Object To count all table rows
public function count()
{
return (int) $this->_table->getAdapter()->fetchOne(
$this->_table->select()->from($this->_table, 'COUNT(id)')
);
}