In SQL Server allows the use of the ISNULL function, which validates if the output is null and closes the default you set. Together I share your query for SQL Server, Mysql and Oracle.
SQL Server
 select 
    ISNULL(master.VALPROV13, 0) VALPROV13ACUM 
    from PFHSTPROV master (NOLOCK),PFUNC a 
    where master.CHAPA=a.CHAPA
    and
    (  ((master.CODCOLIGADA=2) 
    and  (master.CHAPA=001024)))  
    and (  master.MES = 07
    and master.ANO = 2018  )  
Mysql
 select 
    IFNULL(master.VALPROV13, 0) VALPROV13ACUM 
    from PFHSTPROV master (NOLOCK),PFUNC a 
    where master.CHAPA=a.CHAPA
    and
    (  ((master.CODCOLIGADA=2) 
    and  (master.CHAPA=001024)))  
    and (  master.MES = 07
    and master.ANO = 2018  )  
Outra opção...
 select 
    COALESCE(master.VALPROV13, 0) VALPROV13ACUM 
    from PFHSTPROV master (NOLOCK),PFUNC a 
    where master.CHAPA=a.CHAPA
    and
    (  ((master.CODCOLIGADA=2) 
    and  (master.CHAPA=001024)))  
    and (  master.MES = 07
    and master.ANO = 2018  )  
Oracle
 select 
    NVL(master.VALPROV13, 0) VALPROV13ACUM 
    from PFHSTPROV master (NOLOCK),PFUNC a 
    where master.CHAPA=a.CHAPA
    and
    (  ((master.CODCOLIGADA=2) 
    and  (master.CHAPA=001024)))  
    and (  master.MES = 07
    and master.ANO = 2018  )  
							
							
						 
Use the coalesce function, for your case: coalesce(field_que_pode_ser_nulo, 0).
– anonimo