Enum CaseRule 

pub enum CaseRule {
    Upper,
    Lower,
    Insensitive,
    Sensitive,
}

How one identifier class folds before an equality comparison — the per-class element of an IdentifierCasing.

The four cases the cross-dialect matrix reduces to once instance-specific models (filesystem-dependent, collation-dependent) are resolved to a concrete choice. Which dialect gets which rule lives in IdentifierCasing::for_dialect; this enum describes only the folding each rule performs.

Variants

Upper

Unquoted → upper-case; quoted → preserved (exact).

Lower

Unquoted → lower-case; quoted → preserved (exact).

Insensitive

Quoting ignored; comparison case-insensitive.

Sensitive

Quoting ignored; comparison case-sensitive (exact).

Used both by definitively case-sensitive engines and as the safe fallback for filesystem-dependent real table names, where over-matching (a false merge of two distinct stored tables) is a data-correctness risk. Statement-local aliases don’t take this fallback — they default lenient (see IdentifierCasing::table_alias).

Trait Implementations

impl Clone for CaseRule

fn clone(&self) -> CaseRule

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for CaseRule

impl Debug for CaseRule

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

Formats the value using the given formatter.

impl Eq for CaseRule

impl PartialEq for CaseRule

fn eq(&self, other: &CaseRule) -> 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.

impl StructuralPartialEq for CaseRule