sp_defaultlanguage (Transact-SQL MetaData) Definition

Please note: that the following source code is provided and copyrighted by Microsoft and is for educational purpose only.
The meta data is from an SQL 2012 Server.

I have posted alot more, find the whole list here.

Goto Definition or MetaData

Definition:

sys.sp_defaultlanguage(nvarchar @loginame
, nvarchar @language)

MetaData:

 create procedure sys.sp_defaultlanguage  
    @loginame sysname,            --  login name  
    @language sysname = NULL    --  default language  
as  
    --  SETUP RUNTIME OPTIONS / DECLARE VARIABLES --   
    set nocount on  
    declare @exec_stmt nvarchar(4000)  
    declare @ret    int    --  return value of sp call  
  
    --  DISALLOW USER TRANSACTION --   
    set implicit_transactions off  
    IF (@@trancount > 0)  
    begin  
        raiserror(15002,-1,-1,'sys.sp_defaultlanguage')  
        return (1)  
    end  
  
    --  VALIDATE LOGIN NAME:  
    execute @ret = sys.sp_validname @loginame  
    if (@ret <> 0)  
        return (1)  
  
    BEGIN TRANSACTION  
        --  LOCK LOGIN --   
    EXEC %%LocalLogin(Name = @loginame).Lock(Exclusive = 0)  
  
    --  ADD ROW FOR NT LOGIN IF NEEDED --   
    if @@error <> 0    --  not found  
    begin  
        execute @ret = sys.sp_MSaddlogin_implicit_ntlogin @loginame  
        if (@ret <> 0)  
        begin  
            ROLLBACK TRANSACTION  
            raiserror(15007,-1,-1,@loginame)  
            return (1)  
        end  
        --  login locked  
    end  
  
    if (@language is null)  
    begin  
        select @language = name from master.dbo.syslanguages  
        where langid = @@default_langid  -- default language  
  
        if @language is null  
            select @language = N'us_english'  
    end  
  
    --  CHANGE DEFAULT LANGUAGE --   
    set @exec_stmt = 'alter login ' + quotename(@loginame) +  
                ' with default_language = ' + quotename(@language)  
      
    exec (@exec_stmt)  
  
    if @@error <> 0  
    begin  
        ROLLBACK TRANSACTION  
        return (1)  
    end  
      
    COMMIT TRANSACTION  
  
    --  RETURN SUCCESS --   
    return (0) --  sp_defaultlanguage