Question

i have this code for my webdb, i try to delete an item and set the order to the other one, but it change only the last item.

for (var i=ordine2; i < lunghezza-1+ordine2; i++) {
    var db = miodb.webdb.db;
    var ordine3=ordine2+i+1;
    var ordine4=ordine2+i;
       db.transaction(function(tx){
        tx.executeSql("UPDATE todo SET ordine = " + "'" + ordine4 + "'" + " WHERE ordine=?", [ordine3],      
            miodb.webdb.onSuccess, 
            miodb.webdb.onError);
        });
      }

this is my table:
id | content | order

1 |
0 |
0 |

2 |
1 |
1 |

3 |
2 |
2 |

4 |
3 |
3 |

5 |
4 |
4 |

6 |
5 |
5 |

If i delete the first item i wants that all the other item change the order to current order -1, but it doesn’t works, only the last item change the order, ordine2 is set to 0, lunghezza is the length of array.
Who can i fix it?

Answer 1

You don’t need a loop for this at all. What about the following update statment?

UPDATE todo SET ordine = ordine - 1

You might need to add an appropriate where clause on that, some thing like “WHERE ordine > ordine2”. I don’t fully understand what it is you’re trying to do so I can’t give you the exact code.

Also, you really shouldn’t be using string concatenation at all in building your SQL statement, use a ? for every parameter and put them in the array as you did for ordine3, that way you know they’ll be properly escaped.