Oracle

How to connect JSP to MySQL database First, copy the MySQL database connection driver to the tomcat/common/lib package. Download mysql-connector-java-5.1.6.zip Http://mysql.cs.pu.edu.tw/Downloads/Connector-J/mysql-connector-java-5.1.6.zip Configure

The ORACLE tutorial is: Oracle SQL Performance Optimization Series 1. 1. select an appropriate ORACLE optimizer There are three optimizer types in ORACLE: A. RULE (RULE-based) B. COST (COST-based) c. CHOOSE (selectivity) Set the default optimizer.

The ORACLE tutorial is: Security Policy of Oracle Database. ---- Oracle is a relational database management system with powerful functions and excellent performance. It plays an important role in today's large database management systems. In the MIS

The ORACLE tutorial is the design and development of the application database system on the Oracle platform. Oracle is currently the most widely used database system. A complete database system includes system hardware, operating system, network

This article describes how to replace NULL values in SQL Server, Oracle, and MySQL.In SQL Server Oracle MySQL What should I do if I find a NULL value in the database?1. MSSQL: ISNULL ()SyntaxJava codeCopy codeThe Code is as follows:ISNULL

There are a lot of content about oracle optimization and the concept is complex, but you can summarize an outline as the direction to be considered, and then gradually refine it. The design, development, and adjustment of oracle optimization should

1 The syntax of the SQL statement is verified.SQL syntax check2 The data dictionary is searched to verify table and column definitions.Checklist name and field name from data dictionary3 The data dictionary is searched to verify security privileges

1.The SYS user has the DBA permission and the SYS mode, and can only log on to the database through SYSDBA. Is the account with the highest permissions in the Oracle databaseSYSTEM has the DBA permission. However, you do not have the SYSDBA

1. View Overview A view is actually a query SQL statement used to display relevant data in one or more tables or other views. The view uses the results of a query as a table. Therefore, the view can be viewed as a stored query or a virtual table.

The original statement is as follows:Select sum (sl0000) from xstfxps2 whereDhao00 in (Select dhao00 from xstfxps1 where trunc (ywrq00) = trunc (sysdate)And khdm00 = '000000 ');Time in use: 00: 02: 49.04　　 Execution Plan------------------------------

Environment: machine A and machine B are both LINUX systems. However, machine B has insufficient space, so after the database service is stopped, you are ready to export data on machine.Export Statement exp user/password @ sid file = 0320.dmpThe

Number (, ) Precision p value range: 1 ~ 38Valid bit s value range:-84 ~ 127 Maximum integer digit = p-s S is a positive number, and the specified position on the right of the decimal point starts rounding.Negative Number of s. The specified

The ORACLE tutorial is: MySQL Security Guide (2) (). MySQL Security Guide (2)Author: Yan Zi2.1.3 database and table PermissionsThe following permissions apply to database and table operations.ALTERAllow you to use the alter table statement. This is

The ORACLE tutorial is: use and maintain the password file of the Oracle database.Summary:Oracle relational database system has been widely used for its excellent performance. Ensuring database security is an important part of database management.

The ORACLE tutorial is: Oracle Database Security Policy Analysis (1 ). Database security has always been a nightmare for database administrators. The loss of database data and the intrusion of illegal database users make the database administrators

The ORACLE tutorial is about Oracle database backup. I. significance:When we use a database, we always hope that the database content is reliable and correct. However, due to computer system faults (hardware faults, network faults, processes)Faults

If undo damage is unfortunately encountered in Oracle running, the best way is to recover it completely. However, if there is no backup, you can use an unconventional method (using Oracle's hidden parameters ),If undo contains uncommitted

Copy codeThe Code is as follows:-- Oracle reads SQL statements from last Monday to weekend-- The day of the week starts on Sunday.Select to_char (to_date ('201312', 'yyyymmdd'), 'D') from dual;-- Result: Note 6: the sixth day of the week is

1. select * from emp; 2. select empno, ename, job from emp; 3. select empno number, ename name, job from emp; 4. select job from emp; 5. select distinct job from emp; 6. select distinct empno, job from emp;Note: Because employee numbers are not

Indexing is the most effective way to improve data query and the most difficult technology to master, because correct indexing may increase the efficiency by 10000 times, and invalid indexing may waste database space, the query performance is even