Tag：oracle
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Time：2021-9-14
Method of connecting JSP to MySQL databaseFirst, copy the MySQL database connection driver to the Tomcat / common / lib packageDownload mysql-connector-java-5.1.6.ziphttp://mysql.cs.pu.edu.tw/Downloads/Connector-J/mysql-connector-java-5.1.6.zip Configure Tomcat’s virtual directory – omittedCreate a JDBC mysql.jsp pageThe page code is as follows: Copy codeThe code is as follows: <%@ page contentType=”text/html;charset=gb2312″%> <%@ page import=”java.sql.*”%> <% final String MYSQLDBDRIVER=”org.gjt.mm.mysql.Driver”; final String […]
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Time：2021-9-2
The best way to install Oracle system under Linux is 1G memory, 2G swap space, and at least 4.5g hard disk space. At least the environment is above Linux server release 5.3 For Linux server release 5.1, modify Oracle 10.2g 1、 View Linux version [[email protected] ~]# cat /etc/issueRed Hat Enterprise Linux Server release 5.5 (Tikanga) […]
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Time：2021-6-30
Essential difference Oracle database is an object relational database management system MySQL is an open source relational database management system (free) The security of database MySQL uses three parameters to authenticate users, namely user name, password and location Oracle uses more security functions, such as user name, password, configuration file, local authentication, external authentication, advanced […]
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Time：2021-6-30
Essential difference Oracle database is an object relational database management system MySQL is an open source relational database management system (free) The security of database MySQL uses three parameters to authenticate users, namely user name, password and location Oracle uses more security functions, such as user name, password, configuration file, local authentication, external authentication, advanced […]
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Time：2021-6-6
Someone asked in the community: when C # calls the return value of a custom function in Oracle, it cannot be called normally. But in PL / SQL, the normal call returns. So I started to have a try 1. Preparation function (ORALCE 11g. 2.0.0.4) CREATE OR REPLACE FUNCTION F_Update_Grade(v_UserID in Number) return nvarchar2 is […]
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Time：2021-5-11
preface Some time ago, our company’s project was to transfer SQL server to Oracle, and we found that there was less information on this aspect on the Internet. So let’s share our experience and record the problems. Let’s take a look at the detailed introduction At first I studied it for a while and then […]
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Time：2021-3-18
Oracle is a powerful relational database management system built by Oracle company with its 30 years of design experience. Oracle command is used to back up the database, generate DMP file, and save the whole set of user and table data information. And it’s easy to restore. With the batch bat command of Widnows, the […]
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Time：2021-2-23
From studying in university to working on the performance optimization of professional database in the past 10 years, I have been in touch with database for 20 years. During this period, I have made countless mistakes and gained a lot, but they are all complicated. Every time I train new colleagues or talk with my […]
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Time：2021-1-6
Installation procedure Download address: for version 6.0, first install Oracle VM VirtualBox, and then click new After the new page pops up:Set name, installation folder, type and versionThe name should be in English, and the installation path should be placed on the disk with large solid-state disk memory space. The following version is recommended. After […]
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Time：2020-12-28
Rownum is a unique writing method in Oracle. Rownum can be used to get the first data in Oracle, or limit the number of batch writes when batch writes data How to write the first data in MySQL SELECT * FROM t order by id LIMIT 1; How to write the first data in Oracle […]
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Time：2020-12-5
1. View the character set of the database The character set of the database must be consistent with the environment variables set under Linux, otherwise there will be garbled code. The following two SQL statements can be found: select * from nls_database_parameters t where t.parameter=’NLS_CHARACTERSET’; select * from v$nls_parameters where parameter=’NLS_CHARACTERSET’; The query result is: […]
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Time：2020-12-5
Here are some examples to illustrate the use of regular expressions to deal with some common problems in work.1. REGEXP_SUBSTR REGEXP_ The substr function uses regular expressions to specify the start and end points of the return string, and returns source_ String a string with the same VARCHAR2 or CLOB data in the string character […]
