most used database software

Yesterday, when he was dealing with the database of the online forum, he found that he used the post number as the primary key. Due to some accidental modifications to it, the association of the post became messy. So we discussed how to select the primary key in the database table. I am not familiar with the program of the forum, so I don't know how it is designe

ExcelFileParser can be used to import data in excel to the database in batches. ExcelFileParser can be used to import data in excel to the database in batches and submit the form! The DOCTYPEhtmlPUBLIC-W3CDTDXHTML1.0TransitionalENwww.w3.orgTRxhtml1DTDxhtml ExcelFileParser processes excel to obtain data that can be impo

Tags: database tuning MySQL database index fuzzy queryThird, index 7.4 ways to solve like '%str ' without using fuzzy queries Last said, as long as the fuzzy query fuzzy values in front of the string, the index will not be used, '%aaa ' and ' _aaa ' are not! As follows It should be said that this is the MySQL to the programmer to open a joke. What if my table

Tags: Oracle database table Space sizeTo see the size of the Oracle database table space, you need to increase the table space data files, in database Management , the lack of disk space is a problem that DBAs encounter, the problem is more common.--1, viewing the percentage of table space already usedSQL code Select a.tablespace_name,a.bytes/1024/1024 "Sum

Part 1 Database SQL language Database script file Layout The Code layout of database script files has the following significance: (1) demonstrates a good logic structure of the Code, improving the accuracy, continuity, readability and maintainability of the Code. (2) It is conducive to improving product development quality and efficiency, and reducing developmen

In SQL ServerEach database has a table generated by the system.The table sysobjects records all the table names in the database.We can use the following SQL syntax for query operations. Copy codeThe Code is as follows:Select Name, id from sysobjects where xtype = 'U' Xtype = 'U' indicates the table used. If xtype = 's' is used'The default table There is also a table named syscolumns in the system table.H

The following stored procedure is used to search for a string in all tables in a database. ---- Use: exec search 'zhangsan' Create procedure search @ STR varchar (100), @ searchflag Int = 1, @ tableflag Int = 1/**** @ STR: string to be searched** @ Tableflag 1: search only in the User table; 2: search only in the system table; others: Search in all tables** @ Searchflag 1: exact query; others: fuzzy query*

/2007020916013.html) you can use the preceding statement to create a view, in this way, when a table is added to the database, accurate structure information can be obtained in a timely manner. This view is especially useful when many tables are encountered during development, and the Program requires dynamic display of results. For example, to dynamically display different table information on a page, you can use the content in this view to outp

#! /Usr/bin/ENV python2.7 #-*-coding: UTF-8-*-# file: w7.py # Date: 2013-7-18 # Author: wangyuimport reimport sqlite3 "when you feel sad for some days, you must experience some different things that will make you more powerful, thank you for the hardships and thoughts the world has given me. "start to learn regular expressions" email Registration System "class e_mail: def xuanze (self, xuanxian): If (xuanxian = 'Z'): Print "Welcome to register" Elif (xuanxian = 'D'): Print "Welcome to" else: pri

Ask about scheduled task execution bat file, mainly used to update server database regularly

(status)(from Show status return information)Current number of connections: threads_connected (status)(from Show status return information)Number of active connections: threads_running (status)(from Show status return information)Number of Cache connections: Threads_cache (status)(from Show status return information)5. Traffic statistics (taken from show status return information)Bytes_received (bytes accepted), bytes_sent (number of bytes sent)6. Number of connections (taken from show status r

Eight, King eggs, cattle, cattle two, Zhang Wei and so onSelect T.userid,t.operatorname, ASCII (SUBSTRB (Trim (t.operatorname), up)) from Sys_user t where AscII (SUBSTRB (Trim ( T.operatorname) This is the ASC code to judge, 32 is the Chinese language.5. Delete a columnALTER TABLE ipms_parameters DROP COLUMN endtime;6, Ching:Select object_name,machine,s.sid,s.serial#From V$locked_object l,dba_objects O, v$session swhere l.object_id = o.object_id and l.session_id=s.sid;Alter system kill session

Tags: how virtual machine Server databases1, the Vcpus number is equal to or less than the physical core of a single physical CPU.For example, a 4-way 8-core physical server that creates a virtual machine, the number of cores recommended for the virtual machines is 8 cores, or smaller.2, the number of slots recommended "1"3, the VRAM number of virtual machine is not higher than the number of NUMA node memory.For example, the physical server is 4-Channel 8-core, 256G of memory, then the virtual m