pub struct DeclaredOnly {
pub keyword: &'static str,
pub note: &'static str,
}Expand description
What a declaring-but-not-enforcing engine says about its own constraints.
Fields§
§keyword: &'static strThe engine’s own words, appended to every key constraint it renders
— BigQuery’s " NOT ENFORCED", leading space included, because the
suffix is concatenated onto the constraint text.
"" where the engine has no such keyword. That is not a lesser answer:
it is the honest one for Redshift, and it is what routes the fact into
ConstraintEnforcement::ddl_note instead.
note: &'static strOne sentence saying what this engine does with a declared constraint, written for whoever is reading the rendered DDL.
Say what is and is not guaranteed, and where the guarantee has to come from instead — a reader who learns only “not enforced” still does not know whether their data is safe. It is rendered inside a SQL comment, so keep it to prose and never spell a statement.
Required even when keyword is non-empty: the docs read it in both
cases, and only the DDL note is skipped where the keyword already
speaks.