chenhao0568的专栏

无需库import java.io.FileOutputStream;import java.io.IOException;import java.net.MalformedURLException;import java.net.URL;import java.nio.channels.Channels;import java.nio.channels.ReadableByteChannel;public class CopyOfTest { public static void ma

1.定义用户变量(或者赋值)set @变量名=值-- 创建自定义用户变量，当当前的用断开连接的时候就会消失set @value=1;set @pid=1162;set @smart_id=1356;select * from tb_iot where corp_id=115 and pid=@pid and properties like CONCAT('%',@sma...