將DATE轉換爲TEXT以便在SQL數據庫中使用

Question

我目前正在使用sql數據庫做一個簡單的記事應用程序。我有三個輸入字段（標題，註釋，日期）。對於標題和備註我有輸入類型TEXT，並且對於日期我有一個輸入類型DATE，其中點擊文本區域時出現一個彈出式日曆，因此用戶可以從日曆中進行選擇而不必鍵入。 但是，我將這個日期數據發送到sql有一些問題，文本要麼不出現，要麼我沒有定義，如果我玩弄代碼。目前，代碼如下，注意事項不能被添加在所有：

 //Test for browser compatibility 
     if (window.openDatabase) { 
     //Create the database the parameters are 1. the database name 2.version 
     number 3. a description 4. the size of the database (in bytes) 1024 x 1024 = 1MB 
     var mydb = openDatabase("notes_db", "0.1", "A Database of Notes", 1024 * 
    1024); 


    //create the notes table using SQL for the database using a transaction 
    mydb.transaction(function(t) { 
    t.executeSql("CREATE TABLE IF NOT EXISTS notes (id INTEGER PRIMARY KEY 
    ASC, title TEXT, note TEXT, vdate DATE)"); 
    }); 



    } else { 
    alert("WebSQL is not supported by your browser!"); 
    } 

    //function to output the list of notes in the database 

    function updateNoteList(transaction, results) { 
    //initialise the listitems variable 
     var listitems = ""; 
    //get the note list holder ul 
     var listholder = document.getElementById("notelist"); 

    //clear notes list ul 
     listholder.innerHTML = ""; 
     var i; 

//Iterate through the results 
    for (i = 0; i < results.rows.length; i++) { 
     //Get the current row 
     var row = results.rows.item(i); 
     listholder.innerHTML += "<li>" + "<b>" + "<u>" + row.title 
     + "</u>" + "</b>" + "<br>" + row.note + "<br>" + "<br>" + row.vdate + " 
     (<a href='javascript:void(0);' onclick='deleteNote(" + row.id + 
     ");'>Delete Note</a>)" + "</li>" + "<br>" ; 
    } 

} 

    //function to get the list of notes from the database 

    function outputNotes() { 
    //check to ensure the mydb object has been created 
    if (mydb) { 
    //Get all the notes from the database with a select statement, set 
    outputNoteList as the callback function for the executeSql command 
    mydb.transaction(function(t) { 
     t.executeSql("SELECT * FROM notes", [], updateNoteList); 
    }); 
} else { 
    alert("db not found, your browser does not support web sql!"); 
}  



    function addNote() { 
     //check to ensure the mydb object has been created 
     if (mydb) { 
     //get the values of the title and note text inputs 
     var title = document.getElementById("title").value; 
     var note = document.getElementById("note").value; 
     var date = document.getElementById("date").value; 
     //Test to ensure that the user has entered both a title and note 
     if (title !== "" && note !== "") { 
     //Insert the user entered details into the notes table, note the use 
     of the ? placeholder, these will replaced by the data passed in as 
     an array as the second parameter 

     //here, the code had been as follows: 
     //mydb.transaction(function(t) { 
     //t.executeSql("INSERT INTO notes (title, note, date) VALUES (?, 
     //?,?)", [title, note, date]); 
     //alert("Note successfully added"); 
     //}); 

     mydb.transaction(function(t) { 
      t.executeSql("INSERT INTO notes (title, note, date) VALUES (?, 
      ?,TO_DATE('', DD/MM/YYYY))", [title, note, date]); 
      alert("Note successfully added"); 
     }); 
    } else { 
     alert("You must enter a title and note!"); 
    } 

Answer 1

看起來你正在使用HTML5 WebSQL實際上SQLite是引擎蓋下。
在SQLite中，沒有日期數據類型。只能將價值儲存爲TEXT。
稍後，您可以使用各種Date And Time Functions進行比較，計算和顯示。
您可以查看文檔以瞭解更多詳情。