SQLite INSERT 和 DELETE 查询给出错误，但不是 SELECt 查询

Question

我正在使用 SQLite(WebSQL) 在我的 Cordova 移动应用程序中本地保存表单数据。
下面的代码适用于相同 table 的 SELECT 查询，但不适用于 INSERT 或 DELETE 查询。

它输出错误为：could not prepare statement

const usersDB = {
    add: function (firstname, lastname, dob, email, phone, city, state, country) {
        databaseHandler.db.readTransaction(
            function (tx) {
                tx.executeSql(
                    "INSERT INTO users(firstname, lastname, dob, email, phone, city, state, country) VALUES(?, ?, ?, ?, ?, ?, ?, ?)",
                    [firstname, lastname, dob, email, phone, city, state, country],
                    function (tx, results) {
                        console.log('User has been saved');
                    },
                    function (tx, error) {
                        console.log('ERROR: Failed to add user', error);
                    }
                );
            }
        );
    },
    selectAll: function (listUsers) {
        databaseHandler.db.readTransaction(
            function (tx) {
                tx.executeSql(
                    "SELECT * FROM users ORDER BY firstname",
                    [],
                    function (tx, results) {
                        listUsers(results);
                    },
                    function (tx, error) {
                        console.log('ERROR: Failed to list users', error);
                    }
                );
            }
        );
    }
}

我搜索了几十个讨论表，但找不到 post 解决这个问题的方法。
非常感谢您的帮助，并提前致谢。

Answer 1

A read transaction is used for reading only. A write transaction allows both reading and writing. A read transaction is started by a SELECT statement, and a write transaction is started by statements like CREATE, DELETE, DROP, INSERT, or UPDATE (collectively "write statements").

.readTransaction()用于只读查询，.transaction()用于写查询。
所以在我的例子中，我应该这样使用它们：

const usersDB = {
    add: function (firstname, lastname, dob, email, phone, city, state, country) {
        databaseHandler.db.transaction( // Write mode
            function (tx) {
                tx.executeSql(
                    "INSERT INTO users(firstname, lastname, dob, email, phone, city, state, country) VALUES(?, ?, ?, ?, ?, ?, ?, ?)",
                    [firstname, lastname, dob, email, phone, city, state, country],
                    function (tx, results) {
                        console.log('User has been saved');
                    },
                    function (tx, error) {
                        console.log('ERROR: Failed to add user', error);
                    }
                );
            }
        );
    },
    selectAll: function (listUsers) {
        databaseHandler.db.readTransaction( // read-only mode
            function (tx) {
                tx.executeSql(
                    "SELECT * FROM users ORDER BY firstname",
                    [],
                    function (tx, results) {
                        listUsers(results);
                    },
                    function (tx, error) {
                        console.log('ERROR: Failed to list users', error);
                    }
                );
            }
        );
    }
}

SQLite INSERT 和 DELETE 查询给出错误，但不是 SELECt 查询

SQLite INSERT and DELETE query is giving error, but not SELECt query

javascript

sqlite

web-sql

cordova