Instance Property
unionFeatures
A set of feature flags describing the dialect’s support for various forms of
UNION with SELECT queries.var unionFeatures: SQLUnionFeatures { get }
Discussion
See SQLUnionFeatures for the possible flags and more information.
Defaults to [.union, .unionAll].
Default Implementations
SQLDialect Implementations
unionFeaturesDefault implementation ofunionFeatures.
See Also
Support Flags
supportsAutoIncrementtrueif the dialect supports auto-increment for primary key values when inserting new rows,falseif not.supportsIfExiststrueif the dialect supports theIF EXISTSmodifier for all types ofDROPqueries (such asSQLDropEnum,SQLDropIndex,SQLDropTable, andSQLDropTrigger) and theIF NOT EXISTSmodifier forSQLCreateTablequeries.supportsDropBehaviortrueif the dialect supports thebehavior modifiers forDROPqueries,false` if not.supportsReturningtrueif the dialect supportsRETURNINGsyntax for retrieving output values from DML queries (INSERT,UPDATE,DELETE).