Struct RowAccessor 

pub struct RowAccessor<'a> { /* private fields */ }

A view over a Row that supports name-based access via a pre-resolved column-name → index lookup table.

RowAccessor is the parameter type of crate::FromRow::from_row; it borrows the row and a shared lookup map built once per query in fetch_one_as / fetch_all_as.

Example

use hyperdb_api::{FromRow, RowAccessor, Result};

struct User { id: i32, name: String, email: Option<String> }

impl FromRow for User {
    fn from_row(row: RowAccessor<'_>) -> Result<Self> {
        Ok(User {
            id: row.get("id")?,
            name: row.get("name")?,
            email: row.get_opt("email")?,
        })
    }
}

Implementations

impl<'a> RowAccessor<'a>

pub fn get<T: RowValue>(&self, name: &str) -> Result<T>

Returns the named column’s value, decoded as T.

Errors

• Error::Column with ColumnErrorKind::Missing if name is not in the result schema.
• Error::Column with ColumnErrorKind::Null if the cell is SQL NULL.
• Error::Column with ColumnErrorKind::TypeMismatch if the cell value cannot be decoded as T.

pub fn get_opt<T: RowValue>(&self, name: &str) -> Result<Option<T>>

Returns the named column’s value as Option<T>. SQL NULL becomes None; missing columns and type mismatches still error.

Errors

• Error::Column with ColumnErrorKind::Missing if name is not in the result schema.
• Error::Column with ColumnErrorKind::TypeMismatch if the cell is non-NULL but cannot be decoded as T.

pub fn position<T: RowValue>(&self, idx: usize) -> Result<T>

Positional escape hatch: returns the value at column idx, decoded as T.

Errors

• Error::ColumnIndexOutOfBounds if idx is past the row’s column count.
• Error::Column with ColumnErrorKind::Null if the cell is SQL NULL. The synthesized name is col[{idx}].
• Error::Column with ColumnErrorKind::TypeMismatch if the cell value cannot be decoded as T. Same synthesized name.

pub fn position_opt<T: RowValue>(&self, idx: usize) -> Result<Option<T>>

Positional optional access: returns Option<T> for the cell at idx. SQL NULL becomes None; out-of-bounds and type mismatches still error. Mirrors get_opt for positional access.

Errors

• Error::ColumnIndexOutOfBounds if idx is past the row’s column count.
• Error::Column with ColumnErrorKind::TypeMismatch if the cell is non-NULL but cannot be decoded as T. The synthesized name is col[{idx}].

Trait Implementations

impl<'a> Debug for RowAccessor<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.