ORDER BY clause

Sort result by set of expressions in ascending or descending order. It is also used to order nulls in result set by putting them at the start or end of results.

Syntax:

ORDER BY
    <expr> [ASC|DESC] [NULLS FIRST|LAST] [,...]

Order classes by schema and then class name.

SELECT * FROM [meta].[ECClassDef] ORDER BY [Schema].[Id], Name

Order by DisplayLabel but put null values first.

SELECT * FROM [meta].[ECClassDef] ORDER BY [DisplayLabel] NULLS FIRST

ECSql Syntax