Struct Column

pub struct Column<K: ColumnType> { /* private fields */ }

Represents Clickhouse Column

Implementations

impl<K: ColumnType> Column<K>

pub fn iter<'a, T: Iterable<'a, K>>(&'a self) -> Result<T::Iter>

Returns an iterator over the column.

Example

  let pool = Pool::new(database_url);
  let done = pool
      .get_handle()
      .and_then(|c| {
          let sql_query = "SELECT number as n1, number as n2, number as n3 FROM numbers(100)";
          c.query(sql_query).fold_blocks(0_u64, |mut sum, block| {

              let c1 = block.get_column("n1")?.iter::<u64>()?;
              let c2 = block.get_column("n2")?.iter::<u64>()?;
              let c3 = block.get_column("n3")?.iter::<u64>()?;

              for ((v1, v2), v3) in c1.zip(c2).zip(c3) {
                  sum += v1 + v2 + v3;
              }

              Ok(sum)
          })
      })
      .map(|(_, sum)| { dbg!(sum); })
      .map_err(|err| eprintln!("database error: {}", err));

impl<K: ColumnType> Column<K>

pub fn name(&self) -> &str

pub fn sql_type(&self) -> SqlType

Trait Implementations

impl<K: ColumnType> Clone for Column<K>

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<L: ColumnType, R: ColumnType> PartialEq<Column<R>> for Column<L>

fn eq(&self, other: &Column<R>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.