Suppose I want to check if some string appears as name-surname in the concatenation of two rows name and surname of a table. How do I write valid this sql in a rails style ? And is these syntaxes correct ?
SELECT (name + '-'+ surname) FROM table1 where (name + '-'+ surname = string)
table.select(:name+'-'+:surname).where((:name+'-'+:surname) == string)
I am not sure if I am understanding your question correctly, but I think this is what you are wanting. For the following string variable,
string = "John - Doe"
you want to pull a record like this from the User table
id | name | sur_name
1 | John | Doe
If this is what you want, you can actually massage your string variable like this
parsed_string = string.split('-')
name = parsed_string[0].strip # strip to remove white spaces
sur_name = parse_string[1].strip
Then, you can run the following code to get what you want:
users = User.where(:name => name, :surname => sur_name)
Hope this answers your question.
Related
I have the following query which provides me with all the data I need exported but I would like text '' removed from my final query. How would I achieve this?
| where type == "microsoft.security/assessments"
| project id = tostring(id),
Vulnerabilities = properties.metadata.description,
Severity = properties.metadata.severity,
Remediations = properties.metadata.remediationDescription
| parse kind=regex id with '/virtualMachines/' Name '/providers/'
| where isnotempty(Name)
| project Name, Severity, Vulnerabilities, Remediations ```
You could use replace_string() (https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/replace-string-function) to replace any substring with an empty string
I have following
case class Request(name:Option[String], age: Option[Int], address: Option[List[String]])
And I want to construct a query like this the conditions should apply if and only if the field is defined:
val req = Request(Some("abc"), Some(27), Some(List["add1", "add2"])
select name, age, email from user where name = "abc" AND age = 27 AND address in("add1", "add2");
I went through doobies documentation and found about fragments which allow me to do the following.
val baseSql: Fragment = sql"select name, age, email from user";
val nameFilter: Option[Fragment] = name.map(x => fr" name = $x")
val ageFilter: Option[Fragment] = age.map(x => fr" age = $x")
val addressFilter: Option[Fragment] = address.map(x => fr " address IN ( " ++ x.map(y => fr "$y").intercalate(fr",") ++ fr" )"
val q = baseSql ++ whereAndOpt(nameFilter, ageFilter, addressFilter)
from my understanding the query should look like this if all the fields are defined:
select name, age, email from user where name = "abc" AND age = 27 AND address in("add1","add2");
but the query looks like this:
select name, age, email from user where name = ? AND age = ? AND address in(?);
What is wrong here I am not able to find that.
Thanks in advance !!!!
Everything is fine.
Doobie prevents SQL injections by SQL functionality where you use ? in your query (parametrized query), and then pass the values that database should put into the consecutive ? arguments.
Think like this: if someone posted name = "''; DROP table users; SELECT 1". Then you'd end up with
select name, age, email from user where name = ''; DROP table users; SELECT 1
which could be a problem.
Since the database is inserting arguments for you, it can do it after the parsing of a raw text, when such injection is impossible. This functionality is used not only by Doobie but by virtually every modern library or framework that let you talk to database at level higher than plain driver.
So what you see is a parametrized query in the way that database will see it, you just don't see the parameters that will be passed to it.
I have a table and there is a "name" field, but sometimes there are names that are too long, how do I just take the first name, middle name and last name (only 3 words)?
$student = DB::table('student')
->select('student.name')//Split to Firstname, Middlename&Lastname
->get();
I dont think eloquent can do this. You need to use php builtin functions
$fullname = explode(" ", $student);
$firstname = array_shift($split);
$lastname = implode(" ", $split);
Simpliest Way I think. Hope will help you
For me, it's a bad idea of splitting one word(fullname) into three, because what if, there are two words in his firstname, so the problem will exist as you are wishing only three words(first,middle,&lastname).
But if you really want to pursue, here's the code for that:
$student = DB::table('student')
->select(
'student.name',
DB::raw("SUBSTRING_INDEX(student.name, ' ', 1) AS Firstname"),
DB::raw("SUBSTRING_INDEX(SUBSTRING_INDEX(student.name, ' ', 2),' ',-1) AS Middlename"),
DB::raw("SUBSTRING_INDEX(SUBSTRING_INDEX(student.name, ' ', 3),' ',-1) AS Lastname")
)
->get();
I assume you use or it is space(' ') that joins three words (first,middle, & last name)
Note examples outputs:
1. John Ghost Pon
Firstname = "John", Middlename = "Ghost", Lastname = "Pon"
2. Marry Anne Smith Ingram
Firstname = "Marry", Middlename = "Anne", Lastname = "Smith"
SUBSTRING_INDEX Function returns a substring of a string before a specified number of delimiter occurs: More examples
Please let me know if still doesn't work.
Using a PG database filled with registered voters.
Trying to set it up so I can search by first name, last name, zip or city. I want to be able to find all voters that match all of the entered params, but having trouble dealing with empty search fields.
where("zip LIKE ? OR city LIKE ? OR last_name LIKE ? OR first_name LIKE ?",
"#{params[:zip]}","#{params[:city]}","#{params[:last_name]}","#{params[:first_name]}")
Is there a better way to build it out so that it matches ALL entered parameters, but ignores empty string parameters? Right now if I enter a first and last name 'John Smith' I will get 'John Jones' and 'Jane Smith'.
This can do the trick:
attrs_name_to_search = %w( zip city last_name first_name )
fitlered_params = params.slice(*attrs_name_to_search).select { |_,v| v.present? }
sql_cond = filtered_params.map { |k,_| "#{k} LIKE :#{k}" }.join(' OR ')
YourModel.where(sql_cond, filtered_params)
But it should return all the records if no zip/city/last_name/first_name is given.
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 + ",")