cordova-mobile数据库开发参考

wangdazhu0

2013-03-18

使用apache-cordova开发HTML5应用,操作数据库参考如下:

<!DOCTYPE html>
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<html>
  <head>
    <meta name="viewport" content="width=device-width,height=device-height,user-scalable=no,maximum-scale=1.0,initial-scale=1.0" />
    <meta http-equiv="Content-type" content="text/html; charset=utf-8"> <!-- ISO-8859-1 -->
    <title>Cordova Mobile Spec</title>
    <link rel="stylesheet" href="../master.css" type="text/css" media="screen" title="no title" charset="utf-8">
    <script type="text/javascript" charset="utf-8" src="../cordova.js"></script>

      
<script type="text/javascript" charset="utf-8">

    var deviceReady = false;

    //-------------------------------------------------------------------------
    // HTML5 Database
    //-------------------------------------------------------------------------
    var db;
    var callDatabase = function() {
        db = openDatabase("mydb", "1.0", "Apache Cordova Demo", 20000);
        if (db === null) {
            databaseOutput("Database could not be opened.");
            return;
        }
        databaseOutput("Database opened.");
        db.transaction(function (tx) {
            tx.executeSql('DROP TABLE IF EXISTS DEMO');
            tx.executeSql('CREATE TABLE IF NOT EXISTS DEMO (id unique, data)', [],
                 function(tx,results) { console.log("Created table"); },
                 function(tx,err) { alert("Error creating table: "+err.message); });
            tx.executeSql('INSERT INTO DEMO (id, data) VALUES (1, "First row")', [],
                 function(tx,results) { console.log("Insert row1 success"); },
                 function(tx,err) { alert("Error adding 1st row: "+err.message); });
            tx.executeSql('INSERT INTO DEMO (id, data) VALUES (2, "Second row")', [],
                 function(tx,results) { console.log("Insert row2 success"); },
                 function(tx,err) { alert("Error adding 2nd row: "+err.message); });
            databaseOutput("Data written to DEMO table.");
            console.log("Data written to DEMO table.");

            tx.executeSql('SELECT * FROM DEMO', [], function (tx, results) {
                var len = results.rows.length;
                var text = "DEMO table: " + len + " rows found.<br>";
                text = text + "<table border='1'><tr><td>Row</td><td>Data</td></tr>";
                for (var i=0; i<len; i++){
                    text = text + "<tr><td>" + i + "</td><td>" + results.rows.item(i).id + ", " + results.rows.item(i).data + "</td></tr>";
                }
                text = text + "</table>";
                databaseOutput(text);
            }, function(tx, err) {
                alert("Error processing SELECT * SQL: "+err.message);
            });
            tx.executeSql('SELECT ID FROM DEMO', [], function (tx, results) {
                var len = results.rows.length;
                var text = "DEMO table: " + len + " rows found.<br>";
                text = text + "<table border='1'><tr><td>Row</td><td>Data</td></tr>";
                for (var i=0; i<len; i++){
                    text = text + "<tr><td>" + i + "</td><td>" + results.rows.item(i).id + "</td></tr>";
                }
                text = text + "</table>";
                databaseOutput(text);
            }, function(tx, err) {
                alert("Error processing SELECT ID SQL: "+err.message);
            });
            
        },
        function(err) {
            console.log("Transaction failed: " + err.message);
        });


    };

    var readDatabase = function() {
     if (!db) {
     db = openDatabase("mydb", "1.0", "Apache Cordova Demo", 20000);
     if (db === null) {
                databaseOutput("Database could not be opened.");
                return;
     }
        }
        db.transaction(function (tx) {
            tx.executeSql('SELECT * FROM DEMO WHERE id=2', [], function (tx, results) {
                var len = results.rows.length;
                var text = "DEMO table: " + len + " rows found.<br>";
                text = text + "<table border='1'><tr><td>Row</td><td>Data</td></tr>";
                for (var i=0; i<len; i++){
                    text = text + "<tr><td>" + i + "</td><td>" + results.rows.item(i).id + ", " + results.rows.item(i).data + "</td></tr>";
                }
                text = text + "</table>";
                databaseOutput(text);
            }, function(tx, err) {
                alert("Error processing SELECT * WHERE id=2 SQL: "+err.message);
            });
        });
    }

    var databaseOutput = function(s) {
        var el = document.getElementById("database_results");
        el.innerHTML = el.innerHTML + s + "<br>";
    };
    
    /**
* Function called when page has finished loading.
*/
    function init() {
        document.addEventListener("deviceready", function() {
                deviceReady = true;
                console.log("Device="+device.platform+" "+device.version);
            }, false);
        window.setTimeout(function() {
         if (!deviceReady) {
         alert("Error: Apache Cordova did not initialize. Demo will not run correctly.");
         }
        },1000);
    }

</script>

  </head>
  <body onload="init();" id="stage" class="theme">
  
    <h1>HTML5 Database</h1>
    <div id="info">
        <b>Results:</b><br>
        <span id="database_results"></span>
    </div>
    <h2>Action</h2>
    <div class="btn large" onclick="callDatabase();">Create, Add, Read Database</div>
    <div class="btn large" onclick="readDatabase();">Read Database</div>
    <h2> </h2><div class="backBtn" onclick="backHome();">Back</div>
  </body>
</html>

cordova