I have some comma-separated records that I am saving in a MySQL database.
I have the following table and records:
tbl_checks
id | items
----+------
1 | 2,5
2 | 2,3
So I would like to fetch data where one of the comma-separated values in the column items is 5.
I have tried:
$sql = "SELECT * FROM tbl_checks WHERE items="; //unable todo at here
so that I can:
$results = $this->db->query($sql)->result() //codeigniter script
I have also tried
$sql = "SELECT * FROM tbl_checks WHERE items=".in_array(5)//this fails
Your current approach isn't that good, if you want to query against this field. Normally, you would use normalization and split that data into multiple tables which could queried better.
If you have stuck with this approach, you could use LIKE and CONCAT.
$id = '2';
$sql = "SELECT * FROM tbl_checks WHERE CONCAT(',', items, ',') LIKE '%,$id,%'";
$value = 5;
$result = $this->db->where("FIND_IN_SET($value,items) !=", 0)
->get("tbl_checks")->result_array();
I'm agree that such database isn't good constructed. Any way this query should work:
SELECT *
FROM tbl_checks
WHERE ( items LIKE "5,%" )
OR (item LIKE "%,5");
Related
I have mysql column called categories. It can contain single or multiple values like this: 1 or 2 or 1,2,3 or 2,12...
I try to get all rows containing value 2.
$query = "SELECT * FROM my_table WHERE categories LIKE '2'";
$rows = mysql_query($query);
This returns row if column only has value 2 but not 1,2,3 or 2,12. How I can get all rows including value 2?
You can use either of the following:
% is a wildcard so it will match 2 or 1,2, etc. Anything on either side of a 2. The problem is it could match 21, 22, etc.
$query = "SELECT * FROM my_table WHERE categories LIKE '%2%'";
Instead you should consider the find_in_set mysql function which expects a comma separated list for the value.
$query = "SELECT * FROM my_table WHERE find_in_set('2', `categories`)";
Like #jitendrapurohut said, you can do it using
$query = "SELECT * FROM my_table WHERE categories LIKE '%2%'";
$rows = mysql_query($query);
But is really bad to store collections like this. A better aproach is as follow:
categories(id_c, name) => A table with each category
my_table(id_m [, ...])
categories_my_table(id_c, id_m)
Then use this query:
SELECT *
FROM my_table m
INNER JOIN categories_my_table cm ON m.id_m = cm.id_m
INNER JOIN categories c ON cm.id_c = c.id_c
WHERE
c.id_c = 2;
EDIT:
#e4c5 link explains why it is bad to store collections like this...
SELECT * FROM my_table WHERE categories LIKE '%2%' AND categories!='1,2,3' AND categories!='2,12';
i want to query several records by id like:
$ids = array(10,12,14,16,....);
the query would be something like:
select * from users where id=10 or id=12 or id=14 or id=16 ..
is it possible to query it in a more comfortable way like (compared to php):
select * from user where in_array(id, array(10,12,14,16))
thanks
You can use IN instead of OR clauses
select * from users where id IN (put_your_array_here)
Example:
select * from users where id IN (10,12,14,16);
Note:
According to the manual for MySQL if the values are constant IN
sorts the list and then uses a binary search. I would imagine that
OR evaluates them one by one in no particular order. So IN is
faster in some circumstances.
Related post
Try this.
$id = array(10,12,14,16,....);
$ids = join("','",$id);
$sql = "select * from user where id IN ('$ids')";
OR
$ids = implode(',', $id);
$sql = "select * from user where id IN ($ids)";
You can do it like that using implode in PHP:
"select * from users where id in '".implode("','", $ids)."'"
Please be sure that your ids are safe though
I have this query
$query = "Select * FROM table WHERE table.firs_column = 1;
Select * FROM table WHERE table.second_column = 1;
Select * FROM table WHERE table.third_column = 1;
Select * FROM table WHERE table.column = 1";
$stmt = $db->prepare($query);
$result = $stmt->execute();
I want to have multiple results, each one have the result of one query!
how to do it?
It looks like you are using PDO, so you could do something like:
$first_set = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->nextRowset();
$second_set = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->nextRowset();
$third_set = $stmt->fetchAll(PDO::FETCH_ASSOC);
$stmt->nextRowset();
$fourth_set = $stmt->fetchAll(PDO::FETCH_ASSOC);
To get your 4 rowsets.
You can use UNION if table is same for your multiple queries
Select * FROM table WHERE table.firs_column = 1
UNION
Select * FROM table WHERE table.second_column = 1
UNION
Select * FROM table WHERE table.third_column = 1
UNION
Select * FROM table WHERE table.column = 1
After you finish with the first result set, use nextRowset() method to advance to the next result set.
You need to have a PHP MySQL driver extension that supports this method.
Not sure what you're aiming at, but did you try UNION?
Your SQL statement would look like this:
SELECT * FROM table WHERE table.firs_column = 1
UNION
SELECT * FROM table WHERE table.second_column = 1
UNION
SELECT * FROM table WHERE table.third_column = 1
UNION
SELECT * FROM table WHERE table.column = 1;
Please show your desired result if you think of something different.
Since we don't know anything about your database structure, I suggest looking into mysqli::multi_query().
If you're trying to pull related data, I highly suggest you look into doing MySQL JOINs instead. MySQL is another language unto itself that should be learned as a distinct language rather than just a string to be contatenated in PHP.
I know this is very simple, but I haven't used PHP/MySQL in a while and I have been reading other threads/php website and can't seem to get it.
How can I query a single row from a MySQL Table and print out all of the fields that have data in them? I need to exclude the NULL fields, and only add those that have data to an html list.
To clarify, I would like to display the field data without specifying the field names, just for the reason that I have a lot of fields and will not know which ones will be NULL or not.
What you've outlined requires 4 basic steps:
Connect to the database.
Query for a specific row.
Remove the null values from the result.
Create the html.
Step 1 is quite environment specific, so that we can safely skip here.
Step 2 - SQL
SELECT * from <tablename> WHERE <condition isolating single row>
Step 3 - PHP (assuming that $query represents the executed db query)
//convert the result to an array
$result_array = mysql_fetch_array($query);
//remove null values from the result array
$result_array = array_filter($result_array, 'strlen');
Step 4 - PHP
foreach ($result_array as $key => $value)
{
echo $value \n;
}
Just SELECT * FROM table_name WHERE.... will do the trick.
To grab data from specific fields, it would be SELECT field_1,field_2,field_3....
you have to make a string which represent mysql query. Then there is function in php named mysql_query(). Call this function with above string as parameter. It will return you all results. Here are some examples
You need to do it like this...
First connect to your sql... Reference
Now make a query and assign it to a variable...
$query = mysqli_query($connect, "SELECT column_name1, column_name2 FROM tablename");
If you want to retrieve a single row use LIMIT 1
$query = mysqli_query($connect, "SELECT column_name1, column_name2 FROM tablename LIMIT 1");
If you want to fetch all the columns just use * instead of column names and if you want to leave some rows where specific column data is blank you can do it like this
$query = mysqli_query($connect, "SELECT * FROM tablename WHERE column_name4 !=''");
Now fetch the array out of it and loop through the array like this..
while($show_rows = mysqli_fetch_array($query)) {
echo $show_rows['column_name1'];
echo $show_rows['column_name2'];
}
If you don't want to include the column names in the while loop, you could do this:
while($show_rows = mysqli_fetch_array($query)) {
foreach( $show_rows as $key => $val )
{
echo $show_rows[$key];
}
}
I need to select category ids from my sql database.
I have a variable $product_id and for each product id there are three rows in a table that i need to select using PHP.
If I do "SELECT * FROM table_name WHERE product_id='$prodid'"; I only get the one on the top.
How can I select all three category_ids which contain the same product_id?
I suppose you are using PHP's mysql functions, is this correct? I am figuring that your query is actually returning all three rows but you aren't fetching all of them.
$sql = "SELECT * FROM table_name WHERE product_id='$prodid'";
$r = mysql_query($sql, $conn); //where $conn is your connection
$x = mysql_fetch_SOMETHING($r); //where something is array, assoc, object, etc.
The fetch function gives only one row at a time. You say you need three so it needs to be executed three times.
$x[0] = mysql_fetch_assoc($r);
$x[1] = mysql_fetch_assoc($r);
$x[2] = mysql_fetch_assoc($r);
OR this would be better
while($curRow = mysql_fetch_assoc($r)) //this returns false when its out of rows, returns false
{
$categoryIds[] = $curRow['category_id'];
}
If this doesn't do it then your query is actually returning only one row and we need to see your tables/fields and maybe sample data.
SQL seems to be correct, but Why do you store product_id in categories table? if it's one-to-many relation it would be better to store only category_id in products table.
The SQL query is correct for what you want to do. It will select all the records in table_name with the field product_id = $prodid (not only 1 or 3 but any that matches the variable)
To select a few records you should use the LIMIT keyword
You should look inside your table structure and the variable $prodid to find problems.