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I want to make mysql query it look like this:
SELECT name FROM AUTHORS where name LIKE %[here argument]%
I search for solution and i find putting arg in "+[arg]+" like this;
const char * author = getString("Author: ", 100).c_str();
// res type MYSQL_RES* res
res = exec_query(conn, "select name from authors where name like '%"+author+"%'");
But i gives me an error:
expression must have integral or unscoped enum type
You have two problems with your code:
you are storing a dangling pointer in author
you are trying to concatenate multiple const char* pointers.
Change your code to treat author and your concatenated SQL as std::string instead. You can use std::string::c_str() when passing the final SQL string to mysql, eg:
std::string author = getString("Author: ", 100);
// res type MYSQL_RES* res
std::string sql = "select name from authors where name like '%"+author+"%'";
res = exec_query(conn, sql.c_str());
Do be aware that the code above is subject to SQL Injection attacks. You really should be using a parameterized query instead.
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Im new to scala so please go easy on me lol.
I need to create a list of where each spot holds an Int,String. So like [(1,"string1"),(2,"String2")...]
for example, Ive tried
val string1 = "something"
val string2 = "something"
List[Int,String] = List[(1,string1), (2,string), (3,string3),(4,string4),(5,string5)]
and I get the error - identifier expected but integer literal found.
How exactly would I get something like this to work?
(1,"string1") is a tuple containing an Int and a String, so type of list should also be a tuple - (Int, String):
val string1 = "something"
val string2 = "something"
// ... rest of string values
val list: List[(Int,String)] = List((1,string1), (2,string2), (3,string3),(4,string4),(5,string5))
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I am getting values from an api call and it returns one json value/key pair as a string at a time. I need to count how many times items with a certain prefix (which encodes the type of the item) occur:
Lets say I am getting 'abc123' as the 1st value
def getType(nodeName):
nodeCount = 0
if "abc" in nodeName:
count = count + 1
return "ABC", count
How do I retain this nodeCount value so that next time an item with prefix 'abc' comes in from the api call, the count can be incremented to 2.
Also, I need to create other counters to keep track of the count of other node types, such as 'xyz777'.
I tried to declare nodeCount as global variable but if I add "global count", that will defeat the purpose of retaining the count value for the next api call/iteration.
I am very new to python, so please let me know if there is any easy way.
Many Thanks!
You may use a collections.Counter like this:
from collections import Counter
def getType(counter, nodeName):
nodetype= nodeName.rstrip('0123456789')
counter[nodetype] += 1
return nodetype.upper(), counter[nodetype]
c= Counter()
for n in ['abc123', 'def789', 'ghijk11', 'def99', 'abc444']:
nodetype, nodecount = getType(counter= c, nodeName= n)
print('type {} \t: {}'.format(nodetype, nodecount))
print('summary:')
print(c)
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consider:
const int CAP = 20;
struct bookType
{
string bookTitle = "EMPTY";
string ISBN = "EMPTY";
string author = "EMPTY";
string publisher = "EMPTY";
string dateAdded = "EMPTY";
int qty = 0;
double wholesale = 0.00;
double retail = 0.00;
};bookType book[CAP];
What I need to do here is hopefully simple, though I can't seem to get a straight answer on it. I want to search this array of structs (book[]) for a matching bookTitle. for instance, if I have a book named "Star Wars" I need to be able to search the array of structs by typing in "star" and finding a book, "Star Wars". I've been searching for hours, but all the solutions I've found don't seem to actually work.
I don't know the rest of you code so I'll try to give a generic answer.
It seems like you are looking for the find() function for string objects. The find function will return std::string::npos if it does not find anything.
So inside a loop, test:
Booktype[x].bookTitle.find("Star")!=std::string::npos
Change Star to the whatever you are searching for. If this condition is true then you haave a match.
Just a heads up, this is case sensitive so you might want create temporary variables and convert the titles and queries into lowercases and run the loop on them.
Hope this helps.
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The simulation code I use needs to read parameters from an input.txt file which looks like
paramA = 1,paramB = 2,
paramC = 3,paramD = 4,
When scanning a parameter (like paramC) in my simulation, I need to change the value of paramC every time manually. How can I do this with a perl script so that when I type
perl scriptname input.txt paramC 100
in the command line I can get a modified input file with paramC changed to 100
paramA = 1,paramB = 2,
paramC = 100,paramD = 4,
I can do this by creating a template file like
paramA = 1,paramB = 2,
paramC = <>,paramD = 4,
and then use perl to match the mark <> and replace it with the value I want. However is there a more direct way to match the parameter name and change its value ?
thanks.
The obvious answer is to use a regular expression. Perl is quite good at those.
So you could - for example - do:
s/paramC = \d+/paramC = $value/g;
Which'll do the trick I'd have thought?
Edit: Or use TLP's pattern in the comments:
s/^paramC = \K[^ ,]+/$value/g;
or perhaps:
s/^paramC = \K\d+/$value/g;
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I have a list of items of a custom data type Film = String String Int, where the strings are the name and director and Int is the year of release.
What's the best way I would go about making a function that outputs a String or set of strings (doesn't matter how long) which show the information like:
Title: (film title) Director: (director) Released: (released)
You need to define a function that creates a String if given a Film as
an input, e.g.:
data Film = Film String String Int
instance Show Film where
show (Film t d r) =
"Title: (" ++ t ++ ") Director: (" ++ d ++ ") Released: (" ++ show(r) ++ ")"
You can read up on type classes and user-defined show here and here.