I am using CI 'in'operator is not work sql error please check its and share valuable idea...
table
enter image description here
id | coach_name
------------------
9 | GS
------------------
10 | SLR
view and function
$coachID = explode(',',$list['coach']);
$coachname = $this->rail_ceil_model->display_coach_name($coachID);
show result
SLR
need result
GS,SLR
last query result here
SELECT coach_name FROM mcc_coach WHERE id IN('9', '10')
CI code
public function display_coach_name($coachID='')
{
$db2 = $this->load->database('rail',TRUE);
$db2->select('coach_name');
$db2->from('mcc_coach');
$db2->where_in('id',$coachID);
$query = $db2->get();
echo $db2->last_query(); die;
if ($query->num_rows() > 0):
//return $query->row()->coach_name;
else:
return 0;
endif;
}
You must provide an array to in operator so #coachId must be an array not a string
If you are writing this query
SELECT coach_name FROM mcc_coach WHERE id IN('9,10')
it means you are applying in operator on a single id which contains a comma separated value.
So, right query will be
SELECT coach_name FROM mcc_coach WHERE id IN('9','10')
Related
I am wanting to count all occurrences of the # symbol in a field and originally i thought LIKE '%#%' would be the way to go, but if the character appears in the field more than once it only counts it as one.
What other method are there that i could use that would count every occurrence?
Thanks.
EDIT
For anyone needing it, this is what i ended up using that works.
$count = 0;
$sql = mysql_query("SELECT LENGTH(field_name) - LENGTH(REPLACE(field_name,'#','')) AS 'occurs' FROM table_name WHERE field_name LIKE '%#%'");
while ($data = mysql_fetch_assoc($sql)) {
$count += $data['occurs'];
}
echo $count;
select length('aa:bb:cc:dd')-length(replace('aa:bb:cc:dd',':',''));
source: http://lists.mysql.com/mysql/215049
You could make this even simpler by using the ``substr_count function in php. see below.
$message = $row['themessage'];
echo substr_count($message, '#');
what this will return is the number of times # has occurred in your "themessage" field in your database.
I had exported a bunch of tables (>30) as CSV files from MySQL database using phpMyAdmin. These CSV file contains NULL values like:
"id","sourceType","name","website","location"
"1","non-commercial","John Doe",NULL,"California"
I imported many such csv to a PostgreSQL database with TablePlus. However, the NULL values in the columns are actually appearing as text rather than null.
When my application fetches the data from these columns it actually retrieves the text 'NULL' rather than a null value.
Also SQL command with IS NULL does not retrieve these rows probably because they are identified as text rather than null values.
Is there a SQL command I can do to convert all text NULL values in all the tables to actual NULL values? This would be the easiest way to avoid re-importing all the tables.
PostgreSQL's COPY command has the NULL 'some_string' option that allows to specify any string as NULL value: https://www.postgresql.org/docs/current/sql-copy.html
This would of course require re-importing all your tables.
Example with your data:
The CSV:
"id","sourceType","name","website","location"
"1","non-commercial","John Doe",NULL,"California"
"2","non-commercial","John Doe",NULL,"California"
The table:
CREATE TABLE import_with_null (id integer, source_type varchar(50), name varchar(50), website varchar(50), location varchar(50));
The COPY statement:
COPY import_with_null (id, source_type, name, website, location) from '/tmp/import_with_NULL.csv' WITH (FORMAT CSV, NULL 'NULL', HEADER);
Test of the correct import of NULL strings as SQL NULL:
SELECT * FROM import_with_null WHERE website IS NULL;
id | source_type | name | website | location
----+----------------+----------+---------+------------
1 | non-commercial | John Doe | | California
2 | non-commercial | John Doe | | California
(2 rows)
The important part that transforms NULL strings into SQL NULL values is NULL 'NULL' and could be any other value NULL 'whatever string'.
UPDATE For whoever comes here looking for a solution
See answers for two potential solutions
One of the solutions provides a SQL COPY method which must be performed before the import itself. The solution is provided by Michal T and marked as accepted answer is the better way to prevent this from happening in the first place.
My solution below uses a script in my application (Built in Laravel/PHP) which can be done after the import is already done.
Note- See the comments in the code and you could potentially figure out a similar solution in other languages/frameworks.
Thanks to #BjarniRagnarsson suggestion in the comments above, I came up with a short PHP Laravel script to perform update queries on all columns (which are of type 'string' or 'text') to replace the 'NULL' text with NULL values.
public function convertNULLStringToNULL()
{
$tables = DB::connection()->getDoctrineSchemaManager()->listTableNames(); //Get list of all tables
$results = []; // an array to store the output results
foreach ($tables as $table) { // Loop through each table
$columnNames = DB::getSchemaBuilder()->getColumnListing($table); //Get list of all columns
$columnResults = []; // array to store the results per column
foreach ($columnNames as $column) { Loop through each column
$columnType = DB::getSchemaBuilder()->getColumnType($table, $column); // Get the column type
if (
$columnType == 'string' || //check if column type is string or text
$columnType == 'text'
) {
$query = "update " . $table . " set \"" . $column . "\"=NULL where \"" . $column . "\"='NULL'"; //Build the update query as mentioned in comments above
$r = DB::update($query); //perform the update query
array_push($columnResults, [
$column => $r
]); //Push the column Results
}
}
array_push($results, [
$table => $columnResults
]); // push the table results
}
dd($results); //Output the results
}
Note I was using Laravel 8 for this.
I have a table that looks like this (simplified):
CREATE TABLE IF NOT EXISTS records (
user_id uuid NOT NULL
ts timestamptz NOT NULL,
op_type text NOT NULL,
PRIMARY KEY (user_id, ts, op_type)
);
I cannot for practical purposes change the PRIMARY KEY.
I'm trying to write a query that gets all records for a given user_id where, for a specific record, the ts and the op_type don't match an array of exclusions.
I'm not exactly sure of the right postgres terminology so let me see if this example makes my constraint clearer:
This array looks something like this (in JavaScript):
var excludes = [
[DATE1, 'OP1'],
[DATE2, 'OP2']
]
If, for a given user id, there are rows that look like this in the database:
ts | op_type
----------------------------+-------------
DATE1 | OP1
DATE2 | OP2
DATE1 | OP3
DATE2 | OP1
OTHER DATE | OP1
OTHER DATE | OP2
Then, with the excludes from above, I'd like to run a query that returns everything EXCEPT or the first two rows since they match exactly.
My attempt was to do this:
client.query(`
SELECT * FROM records
WHERE
user_id = $1
AND (ts, op_type) NOT IN ($2)
`, [userId, excluding])
But I get "input of anonymous composite types is not implemented". I'm not sure how to properly type excluding or if this is even the right way to do this.
The query may look like this
SELECT *
FROM records
WHERE user_id = 'a0eebc999c0b4ef8bb6d6bb9bd380a11'
AND (ts, op_type) NOT IN (('2016-01-01', 'OP1'), ('2016-01-02', 'OP2'));
so if you want to pass the conditions as a single parameter then excluding should be a string in the format:
('2016-01-01', 'OP1'), ('2016-01-02', 'OP2')
It seems that there is no simple way to pass the condition string into query() as a parameter. You can try to write a function to get the string in the correct format (I'm not a JS developer but this piece of code seems to work well):
excluding = function(exc) {
var s = '(';
for (var i = 0; i < exc.length; i++)
s = s+ '(\''+ exc[i][0]+ '\',\''+ exc[i][1]+ '\'),';
return s.slice(0, -1)+ ')';
};
var excludes = [
['2016-01-01', 'OP1'],
['2016-01-02', 'OP2']
];
// ...
client.query(
'SELECT * FROM records '+
'WHERE user_id = $1 '+
'AND (ts, op_type) NOT IN ' + excluding(excludes),
[userId])
I have a database as below:
TABLE_B:
ID Name LISTID
1 NameB1 1
2 NameB2 1,10
3 NameB3 1025,1026
To select list data of table with ID. I used:
public static List<ListData> GetDataById(string id)
{
var db = Connect.GetDataContext<DataContext>("NameConnection");
var sql = (from tblB in db.TABLE_B
where tblB.LISTID.Contains(id)
select new ListData
{
Name= tblB.Name,
});
return sql.ToList();
}
When I call the function:
GetDataById("10") ==> Data return "NameB2, NameB3" are not correct.
The data correct is "NameB2". Please help me about that?
Thanks!
The value 10 will cause unintended matches because LISTID is a string/varchar type, as you already saw, and the Contains function does not know that there delimiters that should be taken into account.
The fix could be very simple: surround both the id that you are looking for and LISTID with extra commas.
So you will now be looking for ,10,.
The value ,10, will be found in ,1,10, and not in ,1025,1026,
The LINQ where clause then becomes this:
where ("," + tblB.LISTID + ",").Contains("," + id + ",")
I'm trying to use .extra() where the query return more than 1 result, like :
'SELECT "books_books"."*" FROM "books_books" WHERE "books_books"."owner_id" = %s' % request.user.id
I got an error : only a single result allowed for a SELECT that is part of an expression
Try it on dev-server using sqlite3. Anybody knows how to fix this? Or my query is wrong?
EDIT:
I'm using django-simple-ratings, my model like this :
class Thread(models.Model):
#
#
ratings = Ratings()
I want to display each Thread's ratings and whether a user already rated it or not. For 2 items, it will hit 6 times, 1 for the actual Thread and 2 for accessing the ratings. The query:
threads = Thread.ratings.order_by_rating().filter(section = section)\
.select_related('creator')\
.prefetch_related('replies')
threads = threads.extra(select = dict(myratings = "SELECT SUM('section_threadrating'.'score') AS 'agg' FROM 'section_threadrating' WHERE 'section_threadrating'.'content_object_id' = 'section_thread'.'id' ",)
Then i can print each Thread's ratings without hitting the db more. For the 2nd query, i add :
#continue from extra
blahblah.extra(select = dict(myratings = '#####code above####',
voter_id = "SELECT 'section_threadrating'.'user_id' FROM 'section_threadrating' WHERE ('section_threadrating'.'content_object_id' = 'section_thread'.'id' AND 'section_threadrating'.'user_id' = '3') "))
Hard-coded the user_id. Then when i use it on template like this :
{% ifequal threads.voter_id user.id %}
#the rest of the code
I got an error : only a single result allowed for a SELECT that is part of an expression
Let me know if it's not clear enough.
The problem is in the query. Generally, when you are writing subqueries, they must return only 1 result. So a subquery like the one voter_id:
select ..., (select sectio_threadrating.user_id from ...) as voter_id from ....
is invalid, because it can return more than one result. If you are sure it will always return one result, you can use the max() or min() aggregation function:
blahblah.extra(select = dict(myratings = '#####code above####',
voter_id = "SELECT max('section_threadrating'.'user_id') FROM 'section_threadrating' WHERE ('section_threadrating'.'content_object_id' = 'section_thread'.'id' AND 'section_threadrating'.'user_id' = '3') "))
This will make the subquery always return 1 result.
Removing that hard-code, what user_id are you expecting to retrieve here? Maybe you just can't reduce to 1 user using only SQL.