Struct basex::query::query::Query

pub struct Query<T> where
    T: DatabaseStream,  {
    id: String,
    connection: Connection<T>,
}

Represents an XQuery code uniquely identified by the database.

Database query is created out of an XQuery syntax string. The XQuery gets send to the database and associated with an ID. Once the query ID is assigned, the XQuery cannot be changed, but the client may bind arguments or context for it.

Once happy with the arguments bound or context set, the Query can be executed or analysed.

Fields

id: String

connection: Connection<T>

Implementations

impl<T> Query<T> where
    T: DatabaseStream, 

pub(crate) fn new(id: String, connection: Connection<T>) -> Self

pub fn close(self) -> Result<Client<T>>

Closes and unregisters the query with the specified id.

pub fn bind(
    &mut self,
    name: &str,
    value: Option<&str>,
    value_type: Option<&str>
) -> Result<&mut Self>

Binds a value to a variable. The type will be ignored if the value is None.

pub fn execute(self) -> Result<Response<T>>

Executes the query and returns its response.

Example

use basex::{Client, ClientError};
use std::io::Read;

let mut client = Client::connect("localhost", 1984, "admin", "admin")?;
let mut xquery = "declare variable $points := 30;
<polygon>
  {
    for $i in 1 to $points
    let $angle := 2 * math:pi() * number($i div $points)
    return <point x=\"{round(math:cos($angle), 8)}\" y=\"{round(math:sin($angle), 8)}\"></point>
  }
</polygon>".as_bytes();
let query = client.query(&mut xquery)?;

let mut result = String::new();
let mut response = query.execute()?;
response.read_to_string(&mut result)?;

println!("{}", result);

pub fn info(&mut self) -> Result<String>

Returns a string with query compilation and profiling info.

pub fn options(&mut self) -> Result<String>

Returns a string with all query serialization parameters, which can e.g. be assigned to the SERIALIZER option.

pub fn context(
    &mut self,
    value: Option<&str>,
    value_type: Option<&str>
) -> Result<&mut Self>

Binds a value to the context. The type will be ignored if the value is None.

pub fn updating(&mut self) -> Result<bool>

Checks if the query contains updating expressions.