SQLite将数值变量添加到js中的现有值

Question

我有下面的表格

buildingcode buildingreceiptno buildingaddress buildingpay
1012         2                 address 1       0
1001         3                 address 2       0
1003         0                 address 3       0

我想通过一个数值变量来更新某个楼盘代码的楼盘收据

我使用了以下代码，但它不起作用

t.executeSql('UPDATE buildings SET buildingpay = ?, buildingreceiptno = buildingreceiptno + numericalValue WHERE buildingaddress = ?', 
     [myrow.payamount.toFixed(2), myrow.buildingaddress]);

myrow.payamount.toFixed(2)，myrow.buildingaddress是正确的变量

Answer 1

你可以改进它，但这应该是你的问题的一个有效的解决方案：

db.transaction(function(tx) {

  // Get buildingreceiptno value
  tx.executeSql(
    "SELECT buildingreceiptno FROM buildings  WHERE buildingaddress = ?", 
    [myrow.buildingaddress], 
    function(tx, res) {
        var buildingreceiptno = res.rows.item(0).buildingreceiptno;
        tx.executeSql(
            "UPDATE buildings SET buildingpay = ?, buildingreceiptno = ? WHERE buildingaddress = ?",
            [myrow.payamount.toFixed(2), buildingreceiptno + numericalValue, myrow.buildingaddress], 
            function(tx, res) { console.log(tx, res); }, 
            function(tx, err) { console.log('ERROR: ', tx, err); }
        );
    }, 
    function(tx, err) { console.log('ERROR: ', tx, err); }); 
  });

总是使用错误回调来打印错误，这很有帮助。