Encounter a statement

 select itemcode, 
Cuscode, 
The SUM (decode (INSTR (opname, 'before treatment), 
'1', 
Waitqty, 
0)) as qcldqty 
The from BBREPORT c 
Group by itemcode, cuscode 

Combine decode and instr function is used, what is the meaning of this statement

CodePudding user response:

Seems a appear in find opname 'treatment before the position of the string, if position is 1, the sum (waitqty), otherwise the sum (0)