want to execute raw query ,tried with execute but its giving
500 Error: Not implemented
this is the simplest query which is tried to execute
this.tblPlayerRepository.execute(select * from tbl_player,{});
can anyone help me out how to use or execute raw query
If you want to execute a query, you should use this.dataSource.connector.execute instead.
But in your case, it seems, you should use native loopback repository functions instead, like this:
this.tblPlayerRepository.find();
It will return a promise of entities.
Basically I wanted to run any custom query to a datasource.
I tried few options to execute and I found a way to do it.
You can use and this worked for me.
this.dataSource.execute("select * from tbl_player", [])
Related
I am trying to take the value of a drop down I created in grafana, utilizing a query variable.
I am using SimpleJSON for my database.
I have tried this pattern where:
var is my variable that makes up the drop down menu
func is my function call for the database query that creates the graph
So then I wrote:
f.g.func[$var]
I get a Internal Server Error yet when I call func in kdb+ with the values directly, it works fine. So I think I'm passing in var incorrectly.
For grafana/kdb+ adaptor, the syntax is f.g.func["$var"]-- my above attempt lacks the quotes necessary
I have a Python script that runs a pgSQL file through SQLAlchemy's connection.execute function. Here's the block of code in Python:
results = pg_conn.execute(sql_cmd, beg_date = datetime.date(2015,4,1), end_date = datetime.date(2015,4,30))
And here's one of the areas where the variable gets inputted in my SQL:
WHERE
( dv.date >= %(beg_date)s AND
dv.date <= %(end_date)s)
When I run this, I get a cryptic python error:
sqlalchemy.exc.ProgrammingError: (psycopg2.ProgrammingError) argument formats can't be mixed
…followed by a huge dump of the offending SQL query. I've run this exact code with the same variable convention before. Why isn't it working this time?
I encountered a similar issue as Nikhil. I have a query with LIKE clauses which worked until I modified it to include a bind variable, at which point I received the following error:
DatabaseError: Execution failed on sql '...': argument formats can't be mixed
The solution is not to give up on the LIKE clause. That would be pretty crazy if psycopg2 simply didn't permit LIKE clauses. Rather, we can escape the literal % with %%. For example, the following query:
SELECT *
FROM people
WHERE start_date > %(beg_date)s
AND name LIKE 'John%';
would need to be modified to:
SELECT *
FROM people
WHERE start_date > %(beg_date)s
AND name LIKE 'John%%';
More details in the pscopg2 docs: http://initd.org/psycopg/docs/usage.html#passing-parameters-to-sql-queries
As it turned out, I had used a SQL LIKE operator in the new SQL query, and the % operand was messing with Python's escaping capability. For instance:
dv.device LIKE 'iPhone%' or
dv.device LIKE '%Phone'
Another answer offered a way to un-escape and re-escape, which I felt would add unnecessary complexity to otherwise simple code. Instead, I used pgSQL's ability to handle regex to modify the SQL query itself. This changed the above portion of the query to:
dv.device ~ E'iPhone.*' or
dv.device ~ E'.*Phone$'
So for others: you may need to change your LIKE operators to regex '~' to get it to work. Just remember that it'll be WAY slower for large queries. (More info here.)
For me it's turn out I have % in sql comment
/* Any future change in the testing size will not require
a change here... even if we do a 100% test
*/
This works fine:
/* Any future change in the testing size will not require
a change here... even if we do a 100pct test
*/
I have written a function in PostgreSQL for insertion as follows:
CREATE OR REPLACE FUNCTION public.insert_blog("Url" character)
RETURNS void AS
$BODY$Begin
Insert Into "Blogs"("Url") Values("Url");
End$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION public.insert_blog(character)
OWNER TO postgres;
The above function adds an entry into the Blogs table (Url is a parameter).
I am trying to use this function in .Net Core (Npgsql.EntityFrameworkCore.PostgreSQL) as follows:
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Create(Blog blog)
{
if (ModelState.IsValid)
{
//This works fine
var count = _context.Blogs.FromSql("Select insert_blog({0})", blog.Url).Count();
//This doesn't work -- it gives an error of "42601: syntax error at or near "insert_blog""
//var count = _context.Blogs.FromSql("insert_blog #Url={0}", blog.Url).Count();
return RedirectToAction("Index");
}
return View(blog);
}
Can someone tell me why the second command is not working? Also, even if the first command is working, is it the right way?
Since I have to write .FromSql(...).Count() in order for it to work, if I remove .Count() item doesn't get inserted. Can someone tell me why this is happening?
Is there any good article on using .FromSql() or "Using Postgres functions in entity framework core" (I'd guess that this is a new feature and that that's why I couldn't find much data on this)?
Can some one tell me why the second command is not working? Also even if the first command is working, is it the right way?
It's simply just not the way PostgreSQL syntax works. Select insert_blog({0}) is indeed the right way.
Since I have to write .FromSql(...).Count() in order for it to work. If I remove ".Count()" item doesn't get inserted. Can someone tell me why this is happening?
FromSql behaves just like Where and other functions on an IQueryable. Execution is postponed until the results are requested, because it will try to do everything in one database query.
To make sure your query actually gets executed, you need to call a method that returns something other than IQueryable such as .Count() or .ToList(). More info can be found here: https://learn.microsoft.com/en-us/ef/core/querying/overview#when-queries-are-executed
When checking if a query was successful, what is better?
This
$query= "SELECT * FROM `table`";
$mysqliResult = $mysqli->query($query);
if(mysqli_num_rows($mysqliResult)) {
}
Or this:
$query= "SELECT * FROM `table`";
$mysqliResult= $mysqli->query($query);
if(get_resource_type($mysqliResult) === 'mysqli result') {
}
Neither.
Firs one is not an option at all. It'just inapplicable, as empty result is a legitimate result as well - the query was a success anyway.
Besides, in case of an unsuccessful query, this very code will throw an error itself!
The second one could be used for the purpose, but this approach is outdated and extremely inconvenient.
Instead, set mysqli in exception throwing mode, and you will need no code to test for success at all!
First option is better because your are checking only query is success or not but second option we use that when we need to check values and data type are equal ,so first is better
I have this ADO.NET command object and I can set some parameters and execute it successfully.
_mergecommand.Parameters.Add(new SqlParameter("values", SqlDbType.Structured));
_mergecommand.Parameters["values"].TypeName = "strlist";
_mergecommand.Parameters["values"].Direction = ParameterDirection.Input;
_mergecommand.Parameters["values"].Value = valuelist;
_mergecommand.ExecuteNonQuery();
This works fine. But I want to prepare this command before executing it because I need to run this millions of times. I am using SQL Server 2008. I get this error if I try to prepare it
SqlCommand.Prepare method requires all variable length parameters to have an explicitly set non-zero Size.
Any idea how to do this?
This is old, but there does appear to be a correct answer which is to use -1 as the size, e.g.:
_mergecommand.Parameters.Add(new SqlParameter("values", SqlDbType.Structured, -1));
If you have to do it millions of times using a command like this is probably not a good strategy.
Can you serialize your data into an XML string and pass that as a single argument? That will be considerably less load on your network and SQL Server.... although it will probably hit your client a lot harder.
If you are dead set on doing it that way, maybe what you are looking for is an overload of the SqlCommand.Parameters.Add method:
_mergecommand.Parameters.Add("#values", System.Data.SqlDbType.NVarChar, 100).Value = foo;
is that more like what you wanted?