cursor

　　我们可以把loghub当作一个消息中间件来使用。如果能知道当前的消费进度，自然好了，否则消费情况一无所知，总是有点慌！ 　　loghub消费分两种情况，一是普通消费，二是消费组消费； 　　消费组消费，loghub服务端会记录消费情况，这时可以通过调用服务端API进行偏移信息查询。 　　普通消费则不同，需要自行维护偏移量，即只有自己知道偏移信息，自己处理延迟。我们主要讨论这种情况。 一、 消费loghub数据的样例如下： // 普通消费 private static void consumeDataFromShard(int shardId) throws Exception { String cursor = client.GetCursor(project, logStore, shardId, new Date()).GetCursor(); System.out.println("cursor = " +cursor); try { while (true) { PullLogsRequest request = new PullLogsRequest(project, logStore, shardId, 1000, cursor); PullLogsResponse response = client.pullLogs(request); List

I've got a rather large and rather old C application that has been ported to Linux. I'm in charge of getting mouse cursors to work correctly, but having some issues. I was able to convert most of the cursors we require to using the standard cursors provided by XFontCursor by using something like: gCursorTable[waitCurs] = XCreateFontCursor(gDisplay, XC_watch); ... XDefineCursor(gDisplay, WHostWindow(w), gCursorTable[cursor]); XFlush(gDisplay); This is fine for cursors which have analogs in the extremely limited list of (useful) cursors that XFontCursor provides, but there are other built in

简介:游标的使用,处理多行数据(类似于java中的Iterator迭代器,用于集合的遍历),游标基本不处理,直接把结果返回给程序处理,例如java的list　　　　4.1显示游标　　　　　　(1)定义游标 (2)打开游标 (3)提取游标 (4)对游标进行循环操作:判断游标中是否有下一条记录 (5)关闭游标　　　　4.2隐式游标游标判断:游标属性 　　　　%FOUND 　　 布尔型属性,当最近一次读记录时成功返回,则值为TRUE; 　　　　 %NOTFOUND 布尔型属性,与%FOUND相反; 　　　　 %ISOPEN 布尔型属性,当游标已打开时返回TRUE; 　　　　 %ROWCOUNT 数字型属性,返回已从游标中读取的记录数; 1.基本使用方法,while循环 --要求: 打印出 80 部门的所有的员工的工资:salary: xxx declare --1. 定义游标 cursor salary_cursor is select salary from employees where department_id = 80; v_salary employees.salary%type; begin --2. 打开游标 open salary_cursor; --3. 提取游标,(单个值) fetch salary_cursor into v_salary; --正确的做法,循环

import pymysql conn = pymysql.connect( host = '127.0.0.1', port = 3306, user = 'root', passwd = 'tedu', db = 'tedu', charset = 'utf8' ) cursor = conn.cursor() insert_dep = 'insert into departments values(%s, %s)' ##实现增操作 jihe = [(2, '运维部'), (3, '测试部'), (4, '行政部'), (5, '战略部')] ##把值放进去元组，进行批量插入 cursor.executemany(insert_dep, jihe) ##执行语句 conn.commit() ##提交直接结果 cursor.close() conn.close() cursor = conn.cursor() update_dep = 'update departments set dep_name=%s where dep_id=%s' ##实现改操作 cursor.execute(update_dep, ('人力资源部', 1)) ##单个值修改，元组内的值对应sql语句的占位符 conn.commit() cursor.close() conn.close() cursor

I create a Mysql procedure using cursor, but it's run too slow... It's get between 40 and 60 lines by second.. See: DELIMITER $$ CREATE PROCEDURE sp_create(IN v_idsorteio INT,OUT afetados INT) BEGIN DECLARE done INT default 0; DECLARE vc_idsocio INT; DECLARE z INT; DECLARE cur1 CURSOR FOR select IdSocio from socios where Sorteio=1 and Finalizado='S' and CodClientes IS NOT NULL; DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done=1; SET z=1; OPEN cur1; FETCH cur1 INTO vc_idsocio; WHILE done=0 DO -- SELECT register as t; insert INTO socios_numeros_sorteio (IdSocio,IdSorteio,NumerodeSorteio)

i am trying to optimize my application. I noticed that cursor.movetofirst() method somehow slowing the performance of my code. Cursor cursor = myDbHelper.getDayInfo(new SimpleDateFormat("yyyy-MM-dd").format(myCalendar.getTime()); above line executes in 10 ms in 2.1 emulator , and if(cursor != null && cursor.moveToFirst()) this line took about 1.6 seconds . I made little search about this. Somepeople say make it in another thread or in asynctask, but this will make the code more complicated. I 'm just trying to figure out what is actually happening to this cursor. Can anyone simplify or give a