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How to delete duplicates on a MySQL table?
...n an index is going to be slow for large tables. Wouldn't it be better to SELECT MAX(ID) FROM t GROUP BY unique and then JOIN to an exact match of ID to MAX(ID)?
– ebyrob
Nov 10 '16 at 16:31
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Remove border radius from Select tag in bootstrap 3
...s gone, you have to add back in the arrow that visually differentiates the select from the input. Note: appearance is not supported in IE.
Working example: https://jsfiddle.net/gs2q1c7p/
select:not([multiple]) {
-webkit-appearance: none;
-moz-appearance: none;
background-positio...
Fastest way to determine if record exists
...
SELECT TOP 1 products.id FROM products WHERE products.id = ?; will outperform all of your suggestions as it will terminate execution after it finds the first record.
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MongoDB.Driver.MongoConnectionException: Unable to connect to the prim...
MongoDB.Driver.MongoConnectionException: Unable to connect to the primary member of the replica set: Too many threads are already waiting for a connection..
C# Driver:1.3.1
Replset:
localhost:10001 (primary)
localhost:10002 (member)
I have initReplset and add localhost:10002 to the replse...
PHP学习必看的一些书 - PHP - 清泛IT论坛，有思想、有深度
对应初学的PHP，应该买什么样的书？到处问人，到处求助？ 该文章列举了一些书籍，感觉还行，特此重新整理了一下。觉得有些言过其实了，或者是没必要去看的。
该书单我经过一些调整。PHP相关《PHP程序设计》(第2版) –PHP...
AlphaDialog 对话框扩展 - App Inventor 2 拓展 - 清泛IT社区，为创新赋能！
Alpha Dialog 是一个简单但功能强大且易于使用的扩展，您可以在项目中自由使用它来创建令人惊叹且独特的对话框。 该扩展允许您创建透明对话框、全屏对话框，并且通过使用非常简单的技术，您可以使用自定义颜色进行变暗。
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App Inventor 2 Encrypt.Security 安全性扩展：MD5哈希，SHA/AES/RSA/BASE6...
这是关于App Inventor和Thunkable安全性的扩展，它提供MD5哈希，SHA1和SHA256哈希，AES加密/解密，RSA加密/解密，BASE64编码/解码方法。权限此扩展程序不需要任何权限。事件OnErrorOccured抛出任何异常时将触发此事件。此事件中有两个变...
BLE UUID是对的但连接闪退：java.lang.IllegalArgumentException: UUID str...
请问UUID是对的 连接闪退，
下面是报错日志
java.lang.ExceptionInInitializerError
at edu.mit.appinventor.ble.BluetoothLEint$BLEReadOperation.subscribe(BluetoothLEint.java:357)
at edu.mit.appinventor.ble.BluetoothLEint$BLEReadOperation.run(BluetoothLEint.java:325)
at android.os....
Invoke: no method named `…………’ in class java.lang.Boolean - App I...
可能原因1：可能是因为使用了“计时器”组件，而它一直在计时，且触发计时任务导致的。删除不再使用的计时器组件即可解决。
I've deleted the "clock" which was not even in the blocks present...and it works... Maybe it helps someone.
来自...
蓝牙接收的数据怎么一行一行更新显示和，类似图2这样的 - App应用开发 - 清...
在做BLE蓝牙显示app。蓝牙端一个数据一个数据的发送，但是显示的时候后一个会覆盖上一个 无法将接收的数据全部罗列出来，而且显示的还有问题，有时候显示一个，有时候显示3个数据。求解！！使用列表显示框组件，详见文...