Question

I have two tables, TABLESource is where will i get the records to be inserted in TABLEDest,

now TABLESource can contain duplicate fields:

id  code    name
2   09  abc
3   10  uu
2   09  def
3   10  rr
2   09  gh

and i have to insert first all the unique records in the TABLEDest, the id+code is primary key (unique)

id  code    name
2   09  abc
3   10  uu

now, in the end, if the TABLESource found duplicate id and name, it must update the TABLEDest with the latest records found in the TABLESource with the same primary key (id_name)

id  code    name
2   09  gh
3   10  rr

I have no clue how to do that. Please help me. THanks 🙂

Answer 1

I would suggest iterating through your source table and for each row in the source:

Psudo Code:
//Get all source rows
query = 'SELECT * FROM TABLEsource'
rows = database.get(query)

//Iterate through all source rows
for each rows as row{
    //Search dest table for a match    
    checkQuery = 'SELECT * FROM TABLEDest WHERE id = '+row.id
    check = database.get(checkQuery)

    //If we do get a match
    if(check.rows > 0){

       //Update the relevant row
       query = 'UPDATE TABLEDest SET name = '+row.name+' WHERE id = '+check.id
       database.query(query)

    }else{

       //Otherwise, append a new row to the dest table
       query = 'INSERT INTO TABLEDest(id, code, name) '
              +'VALUES('+row.id+'. '+row.code+', '+row.name+')'
       database.query(query)

    }
}

This is psudo code, so directly copying and pasting won’t work, but it should be enough for you to use your favorite flavor of language to make it happen.