显示基于当前时间的 Android SQLite 中表字段“Bus-time”的值。

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英文:

To Display the values in the table field Bus-time based on current time in android sqlite

问题

public List<Contact> getBus(String t)
{
    List<Contact> contactList = new ArrayList<Contact>();
    String query = "SELECT * FROM contacts WHERE CAST( bus_time AS TIME ) >= CAST('" + t + "' AS TIME )";
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db.rawQuery(query, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            Contact contact = new Contact();
            contact.setID(Integer.parseInt(cursor.getString(0)));
            contact.setName(cursor.getString(1));
            contact.setPhoneNumber(cursor.getString(2));
            // Adding contact to list
            contactList.add(contact);
        } while (cursor.moveToNext());
    }

    // return contact list
    return contactList;
}
The Error I am getting is

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.database, PID: 4539
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.database/com.example.database.MainActivity}: android.database.sqlite.SQLiteException: near ":27": syntax error (code 1): , while compiling: SELECT * FROM contacts WHERE CAST( bus_time AS TIME ) >= CAST(18:27 AS TIME )
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6077)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
英文:

My Problem is I need to display all the data in the database based on the field Bus-Time with a comparison with the current time i.e if the current time is 6:30 PM then it should display all the Bus-time field value that is greater than or equal to the current time(6:30).

I had written an SQL query in DatabaseHandler.java in android studio but I am getting error in the query can you help to resolve it out.

The code for the query is.

public List&lt;Contact&gt; getBus(String t)
    {
        List&lt;Contact&gt; contactList = new ArrayList&lt;Contact&gt;();
        String query = &quot;SELECT * FROM contacts WHERE CAST( bus_time AS TIME ) &gt;= CAST(&quot; + t +&quot; AS TIME )&quot;;
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(query, null);
        

        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Contact contact = new Contact();
                contact.setID(Integer.parseInt(cursor.getString(0)));
                contact.setName(cursor.getString(1));
                contact.setPhoneNumber(cursor.getString(2));
                // Adding contact to list
                contactList.add(contact);
            } while (cursor.moveToNext());
        }

        // return contact list
        return contactList;


    }

The Error I am getting is

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.database, PID: 4539
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.database/com.example.database.MainActivity}: android.database.sqlite.SQLiteException: near &quot;:27&quot;: syntax error (code 1): , while compiling: SELECT * FROM contacts WHERE CAST( bus_time AS TIME ) &gt;= CAST(18:27 AS TIME )
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
        at android.app.ActivityThread.-wrap12(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6077)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)

答案1

得分: 0

在SQLite中,没有TIME数据类型,任何日期和/或时间值都应视为TEXT。使用函数STRFTIME()HH:MM格式获取当前时间:

SELECT * 
FROM contacts 
WHERE SUBSTR('0' || bus_time, -5) >= STRFTIME('%H:%M', 'now', 'localtime')

如果您将时间以HH:MM格式(小时为2位数)保存在列bus_time中,则不需要SUBSTR()函数,该函数会在小时只有1位数时在左侧填充0,代码将为:

WHERE bus_time >= STRFTIME('%H:%M', 'now', 'localtime')
英文:

In SQLite there is no data type TIME and any date and/or time values should be treated as TEXT.<br/>
Use the function STRFTIME() to get the current time in format HH:MM:

SELECT * 
FROM contacts 
WHERE SUBSTR(&#39;0&#39; || bus_time, -5) &gt;= STRFTIME(&#39;%H:%M&#39;, &#39;now&#39;, &#39;localtime&#39;)

If you saved the time in the column bus_time in format HH:MM (with 2 digits for the hour), you would not need the function SUBSTR() which pads at the left a 0 if the hour has only 1 digit and the code would be:

WHERE bus_time &gt;= STRFTIME(&#39;%H:%M&#39;, &#39;now&#39;, &#39;localtime&#39;)

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  • 本文由 发表于 2020年8月16日 21:13:49
  • 转载请务必保留本文链接:https://go.coder-hub.com/63437326.html
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