PL/SQL中如何讓程式每隔幾秒插入一條資料在編寫Oracle PL/SQL中,如果需要程式執行中暫停幾秒鐘再繼續執行,可以通過Oracle內建的dbms_lock.sleep來實現,不過dbms_lock包需要使用者自己安裝。[root@oraclevm ~]# su - oracle[oracle@oraclevm ~]$ sqlplus / as sysdbaSQL*Plus: Release 11.2.0.4.0 Production on Mon May 25 16:36:12 201
mysql之字元集與校對集,mysql校對一、字元集1.mysql的字元集設定非常靈活可以設定伺服器預設字元集;資料庫預設字元集;表預設字元集;列字元集;如果某一層級沒有指定字元集,則繼承上一級。查看所有字元集語句:show character set;2.以表聲明為utf-8為例,最終儲存在表中的資料為utf-8 ①我們要告訴伺服器,我給你發送的資料是什麼編碼?character_set_client
Windows 7環境下安裝MongoDB,windowsmongodb1.下載mongodb-win32-x86_64-2008plus-2.6.7-signed.msi(現在最新版本已經到了3.0)2.假設為64位作業系統則雙擊 mongodb-win32-x86_64-2008plus-2.6.7-signed.msi ,否則mongodb-win32-i386-2.6.7-signed.msi 點擊Next選擇接受協議” I accept the terms in
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(三)值運算式介紹,初學者指南讀書筆記CHAPTER 5Getting More Than Simple ColumnsIntro Value expression,itcontains column names, literal values, functions, orother valueexpressions The type of dataTheSQL Standard defines seven general categories
STDistance的使用及geometry和geography的區別,stdistancegeometry1、先說說Sql Server中geometry和geography的區別: geometry:planar 平面座標系統【supported by SQL Server conforms to the Open Geospatial Consortium (OGC)
題目4:MySQL----------Rank Scores,scoresofWrite a SQL query to rank scores. If there is a tie between two scores, both should have the same ranking. Note that after a tie, the next ranking number should be the next consecutive integer value. In other
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.