Struct ColumnDefaults 

pub struct ColumnDefaults { /* private fields */ }

Every declared DEFAULT of one collection, compiled once for a statement.

Build this OUTSIDE the row loop. materialize_row then fills each row from the parsed forms, so a multi-row VALUES clause parses each declaration exactly once however many rows it carries.

Implementations

impl ColumnDefaults

pub fn compile_pairs(pairs: &[(String, String)]) -> Result<Self>

Compile the catalog’s (column_name, default_expr) list.

pub fn compile_columns(columns: &[ColumnInfo]) -> Result<Self>

Compile every declared column that carries a DEFAULT.

pub fn is_empty(&self) -> bool

Whether no column declares a DEFAULT.

pub fn materialize_row( &self, row: &mut Vec<(String, SqlValue)>, catalog: &dyn SqlCatalog, ) -> Result<bool>

Fill in every column of row that declares a DEFAULT and the statement omitted.

Each entry evaluates at most once per row, so a nextval DEFAULT allocates exactly one value per row.

A column the statement supplied stays untouched, an explicit NULL included: NULL is a value the author chose, and overwriting it with the default makes storing one impossible.

Returns whether any default it materialized was volatile, so the caller can keep the plan out of the plan cache.

Trait Implementations

impl Clone for ColumnDefaults

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnDefaults

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

Formats the value using the given formatter.

impl Default for ColumnDefaults

fn default() -> Self

Returns the “default value” for a type.