Rel_sql.SyntaxStandard SQL syntax fragments.
string_to_literal s is s between single quotes ('\'') with single quotes in s properly escaped.
string_of_literal s parses a string literal from s. This removes enclosing single quotes ('\'') and collapses sequences of two quotes to a single one (it leaves lone internal single quotes untouched).
id id is id between double quotes ('\"') with double quotes in s properly escaped.
id_in_schema is like id but prefixes an escaped schema if specified.
val foreign_key_action_keyword : Rel.Table.Foreign_key.action -> string