I'm trying to write a function that returns an array of column names for a MySQL table.
When I use something like this in HeidiSQL
SELECT COLUMN_NAME FROM information_schema.COLUMNS
WHERE table_schema = 'myDB'
AND TABLE_NAME = 'myTable'
I get exactly what I want. A single column of output showing the column names.
when I took the above code and used it in a PHP program using PDO calls every array value is of the format:
string(xx) "column_name"
I do not want the leading "string(xx)" in front of the column name.
I'm using the pdo function as follows:
fetchAll(PDO::FETCH_COLUMN)
I don't see other PDO fetch options to just give me the column names, without the leading "string(xx)" value.
I could parse the results and strip the leading string(xx) value, but I was wondering if there's an easier/better trick.
Oh, mental lapse... as I dug deeper into my output array, I was thrown off by my output because I was using var_dump. var_dump prefaces the values with the "string(xx)" value. MySQL isn't the one putting the "string(xx)" prefix.
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i have a code in sql for string comparison which takes two parameters as input works upon it and returns a result. both of the parameters are words, i want to change the parameter from a single word to a database column. how do i do that?
say for example in java its like storing the data in an array and than passing the whole array. can something like this be done in sql?
You can use the Select query for passing each value of a particular column from the table into your function.
like this,
SELECT compare_city_name('baroda',t.cityname) from tablename as t
In this query, you pass all cities name from cityname column to the function compare_city_name one by one.
Pass it as a VARCHAR, then build the query with "prepare" and "execute" it.
I have an JSON string stored in the database and I need to SQL COUNT based on the WHERE condition that is in the JSON string. I need it to work on the MYSQL 5.5.
The only solution that I found and could work is to use the REGEXP function in the SQL query.
Here is my JSON string stored in the custom_data column:
{"language_display":["1","2","3"],"quantity":1500,"meta_display:":["1","2","3"]}
https://regex101.com/r/G8gfzj/1
I now need to create a SQL sentence:
SELECT COUNT(..) WHERE custom_data REGEXP '[HELP_HERE]'
The condition that I look for is that the language_display has to be either 1, 2 or 3... or whatever value I will define when I create the SQL sentence.
So far I came here with the REGEX expression, but it does not work:
(?:\"language_display\":\[(?:"1")\])
Where 1 is replaced with the value that I look for. I could in general look also for "1" (with quotes), but it will also be found in the meta_display array, that will have different values.
I am not good with REGEX! Any suggestions?
I used the following regex to get matches on your test string
\"language_display\":\[(:?\"[0-9]\"\,)*?\"3\"(:?\,\"[0-9]\")*?\]
https://regex101.com/ is a free online regex tester, it seems to work great. Start small and work big.
Sorry it doesn't work for you. It must be failing on the non greedy '*?' perhaps try without the '?'
Have a look at how to serialize this data, with an eye to serializing the language display fields.
How to store a list in a column of a database table
Even if you were to get your idea working it will be slow as fvck. Better off to process through each row once and generate something more easily searched via sql. Even a field containing the comma separated list would be better.
MySql has a function CONCAT_WS that I use to export multiple fields with a delimiter into a single field. Works great!
There are multiple fields being stored in a database I query off of that has data that I need to extract each field individually but within each field the data need to include a delimiter. I can most certainly do a concatenate but that does take awhile to set-up if my data requires up to 100 unique values. Below is an example of what I am talking about
Stored Data 01020304050607
End Result 01,02,03,04,05,06,07
Stored Data 01101213
End Result 01,10,12,13
Is there a function in MySQL that does the above?
I am not that familiar with mysql but I have seen questions like this come up before where a regular expression function would be useful. There are user-defined functions available that allow Oracle-like regular expression functions to be used as their support is weak in mysql. See here: https://github.com/hholzgra/mysql-udf-regexp
So you could do something like this:
select trim(TRAILING ',' FROM regexp_replace(your_column, '(.{2})', '\1,') )
from your_table;
This adds a comma every 2 character then chops off the last one. Maybe this will give you some ideas.
I'm trying to replicate the following LIKE query using a full text search on JSON data;
SELECT * FROM table
WHERE response LIKE '%"prod_id": "foo"%'
AND response LIKE '%"start_date": "2016-07-13"%'
In my database the above query returns 28 rows
This is my attempt:
SELECT * FROM table
WHERE MATCH(response)
AGAINST('+"\"prod_id\": \"foo\"",+"\"start_date\": \"2016-07-13\""')
However this returns over 4,500 rows (the same as running the first query for only the prod_id ~1,900 rows when running the first query on just the date)
It was my understanding that +"text here" would indicate a required word, and that literal double quotes (present in the JSON data) should be escaped, and that , would indicate a split between the two strings I'm looking for. What am I not understanding correctly? Is there any point in running this as a full text query anyway?
Thanks to #Sevle I've tweaked my query like so, and it's returning the correct results;
SELECT * FROM table
WHERE MATCH(response)
AGAINST('+\"prod_id: foo\" +\"start_date: 2016-07-13\"' IN BOOLEAN MODE)
The comma was not helping and I was escaping the wrong characters, and of course I did need IN BOOLEAN MODE to be added. Finally, I removed the double quotes I was searching for in the JSON string.
It may also be worth noting that as I'm using PHP PDO to run this query I also had to make the following tweaks.
Instead of constructing the query like so trying to bind the variables like I normally would;
$query = $db->prepare('...AGAINST('+\"prod_id: :prod_id\" +\"start_date: :start_date\"');
$query->execute(array('prod_id' => 'foo', 'start_date' => '2016-07-13'));
I had to do this, as I found I could not bind variables in full text searches
$sql_against = $db->quote('...AGAINST('+\"prod_id: foo\" +\"start_date: 2016-07-13\"');
$query = $db->prepare("...AGAINST($sql_against IN BOOLEAN MODE)")
I have a column in my table name as URL and it contains Multiple value like "https://www.google.com/#q=how+to+make+a+android+app"
and
http://www.bing.com/search?q=how+to+make+a+android+app&go=&qs=n&form=QBLH&pq=how+to+make+a+android+app&sc=8-15&sp=-1&sk=
I want to get data separately in output like
website = https://www.google.com
Keyword = how to make a android app.
Any Idea Plz, How can i get this in MySql.
you can use substr() function in php to cut string. In your case, you can get the characters up to the end of 'https://www.google.com'.
read more at http://ro1.php.net/substr
in case you want to do it directly in your query, you can use substr() as well. Sql syntax goes like this:
SELECT SUBSTR(column, start_position, desired_length) FROM table_name
*SELECT SUBSTR(column_name, 1, 20) FROM table_name;*