SET quoted_identifier ON

GO

CREATE PROCEDURE [dbo].[usp_find_row_lenght]
(
  @schema_name VARCHAR(100)=''
  ,@table_name VARCHAR(100)=''
)
AS
  BEGIN
      SET nocount ON

      IF @table_name=''
          OR @schema_name=''
        BEGIN
            SELECT
              ss.name AS schema_name,
              o.name AS table_name,
              SUM(c.length) AS row_lenght
            FROM
              sysobjects o
              INNER JOIN syscolumns c
                ON o.id=c.id
              INNER JOIN sys.objects so
                ON o.id=so.object_id
              INNER JOIN sys.schemas ss
                ON so.schema_id=ss.schema_id
            WHERE  (o.xtype='u')
               AND (o.type='u')
            GROUP  BY
              o.name,
              ss.name
            ORDER  BY
              ss.name,
              o.name
        END
      ELSE
        BEGIN
            SELECT
              ss.name AS schema_name,
              o.name AS table_name,
              SUM(c.length) AS row_lenght
            FROM
              sysobjects o
              INNER JOIN syscolumns c
                ON o.id=c.id
              INNER JOIN sys.objects so
                ON o.id=so.object_id
              INNER JOIN sys.schemas ss
                ON so.schema_id=ss.schema_id
            WHERE  (o.xtype='u')
               AND (o.type='u')
               AND o.name=@table_name
               AND ss.name=@schema_name
            GROUP  BY
              o.name,
              ss.name
            ORDER  BY
              ss.name,
              o.name
        END
  END

GO