Question

Table structure

 sl_ no     A                 B            TOTAL
  1         DUDE             SAM         5
  4         COOL             DUDE        8
  6         KEWL             COOL        8
  8         ROCK             KEWL        10

How to fetch the value if i give SAM it should be able to fetch the TOTAL of DUDE which is in column B

eg:

SAM =DUDE 
    DUDE=COOL
    COOL=KEWL
    KEWL=ROCK

OUTPUT IF I GIVE SAM IT SHOULD FETCH THE DUDE TOTAL=8

Answer 1

If I understand your question here’s the request you need:

SELECT table_o.TOTAL 
    FROM <your_table> AS table_i 
        LEFT JOIN <your_table> AS table_o ON table_i.A = table_o.B
WHERE table_i.B = ?

You join your table on itself using the columns A and B, and then select the total of the outer table you joined.