mysql函數二,mysql函數四、條件判斷函數1、if(expr,v1,v2)函數:成立返回結果v1,否則結果v2例:select id,if(grade>=60,'pass','fail') from t;2、IFNULL(V1,V2)函數:如果空顯示v2,否則顯示v1例:mysql> select a,ifnull(a,'no') from pet76;+------+----------------+| a |
SQL查詢初學者指南讀書筆記(二)建立SQL查詢,初學者指南sqlPARTII: SQL BasicsCHAPTER 4Creating a Simple Query介紹一種如何建立SQL語句的技術--“Request/Translation/CleanUp/SQL” The SELECT operationin SQL can be broken down into three smaller operations,which we will referto as the
SQL 在迴圈內修改欄位值,sql迴圈修改欄位在網站找一段,發現並沒有達到自己的要求:這段程式功能是 為某空欄位自動編號(系統運用時,新加的編號欄位,前期有資料,需要重新編號)declare @id intdeclare @maxid intset @id=1select @maxid=count(*) from t_Send_Revisit Where fSO is nullbegin while @id<=@maxidbeginupdate s set fSO
TNSPING time out/響應慢,tnspingout E:\s01\app\oracle\product\11.2.0\dbhome_1\BIN>tnsping CENORCLTNS Ping Utility for 64-bit Windows: Version 11.2.0.1.0 - Production on 25-MAY-2015 10:26:59Copyright (c) 1997, 2010, Oracle. All rights reserved.
題目6:MySQL----------Employees Earning More Than Their Managers,morethanicansayThe Employee table holds all employees including their managers. Every employee has an Id, and there is also a column for the manager Id.+----+-------+
Yahoo 開源的 MySQL 效能分析工具(MySQL Performance Analyzer),原文地址:https://github.com/yahoo/mysql_perf_analyzer MySQL Performance Analyzer is an open source project for MySQL performance monitoring and analysis. This repository includes two sub