UPDATE T_ORARENDIORA SET C_ORAKEZDETE = CAST(CAST(C_ORAKEZDETE AS TIME) AS DATETIME)
WHERE C_ORAKEZDETE >= '19010102' AND C_TANORANKIVULIFOGLALKOZAS = 'T'
GO

UPDATE T_ORARENDIORA SET C_ORAVEGE = CAST(CAST(C_ORAVEGE AS TIME) AS DATETIME)
WHERE C_ORAVEGE >= '19010102' AND C_TANORANKIVULIFOGLALKOZAS = 'T'
GO

UPDATE T_ORARENDIORA SET C_ORASZAM = NULL 
WHERE C_TANORANKIVULIFOGLALKOZAS = 'T'
GO