Update is used to modify the existing records in a table. You can use Where to filter records.

Sql

Update Table_Name;
Set
    column1 = value1,
    column2 = value2,
Where
    Column3=some_value
and
    Column4=some_another_value;

JsStore

connection.update({ 
      in: "Table_Name",
    set: {
        Column1: value1,
        Column2: value2
    },
    where: {
        Column3: some_value,
        Column4: some_another_value
    }
}).then(function(rowsUpdated) {
    alert(rowsUpdated + ' rows updated');
}).catch(function(err) {
    console.log(err);
});

Example