Oracle

Unable to install and use all functions due to computer system reasons. See this article shared by the IT blog for future preparation Http://blogread.cn/it/article.php? Id = 5347 & F = sinat Note the following when installing Windows 7:

Use the following statement if no data exists. Alter table tb_test modify permile number (5, 2 ); However, if there is data, you cannot use the above method, Alter table tb_test add permile_temp number (5, 2) Update tb_test set permile_temp =

How to delete duplicate data in Oracle Source: Unknown (11:13:48) We may see this situation where a table is not fully designed, leading to duplicate data in the table. How can we delete duplicate

Sqlplus is a common development tool for Oracle databases. Common commands in sqlplus are as follows. 1. Connection command (1). Conn [ect] Usage: conn username/password @ network service name [as sysdba/sysoper]. When connecting with a privileged

1. process null values To process the null value, you can use the nvl function. If comm (Comm, 0) is null, use 0 instead. Otherwise, it is Comm. Example: displays the annual salary of each employee Select Sal * 12 + nvl (Comm, 0) * 12 "annual salary"

Description:In the normal development process, we will find that there are many types of dates, including Java. lang. date, Java. SQL. date, Oracle. jbo. domain. date, And the timestamp oracle. jbo. domain. timestamp and so on. Conversion between

The index clustering factor is a key statistic that can improveboth the Oracle optimizer's performance, and the technician 'sunderstanding of the utility of an index. It is used by Oracle's optimizer to help determine the costassociated with index

Recently, the project has been completed (maybe not enough), but a fatal obstacle is performance. Now let's think about how brilliant the top author is. The performance runs through various stages such as project requirements, project analysis and

Oracle 10g AWR Report Generation Process Oracle10g provides an AWR Report, which is automatically recorded every hour by default. This report is useful in both performance testing and real-time production environments, briefly describe the process

  Oracle interview questions-technical knowledge This may be an article you have been looking forward to. while paying attention to this part of technical questions, please be sure to read personal questions and answers during the interview. The

-- How to import DMP database files in Oracle?2006/2/16 Zhanghua first createImporting and exporting Oracle Data imp/exp is equivalent to restoring and backing up ORACLE data. The exp command can export data from the remote database server to the

Sequence: If you want to query employeesTableMaximum Value of medium IDSelect max (employee_id) from employees; However, to ensure the uniqueness of the primary key insertion, if you use max (employee_id) + 1Because concurrent operations may occur.1

OracleThe statement for creating database jobs is as follows: BeginSYS. dbms_job.submit (job =>: Job,What => 'proc _ YW ;',Next_date => to_date ('13-11-2007 14:00:00 ', 'dd-mm-yyyy hh24: MI: ss '),Interval => 'trunc

A data dictionary is a place where Oracle stores database information. It is used to describe data. For example, the Creator information, creation time information, tablespace information, and user access permission information of a table. You can

Introduction to using cube Functions To introduce the cube function, let's take a look at another example of using rollup.06:53:00 SQL> select area_code, bill_month, sum (local_fare) local_fare06:53:37 2 from t06:53:38 3 group by rollup (area_code,

How to Use % Type and % rowtype in Oracle PL/SQL 1. Using % Type in many cases, PL/SQL variables can be used to store data in database tables. In this case, the variable should have the same type as the table column. For example, if the first_name

The most commonly used cursor operation is to Perform Batch modification or batch deletion operations in the stored procedure. For example, after deleting a master table record, you can execute a stored procedure to delete the detailed records

Start with... connect by in Oracle implements multi-level Recursive understanding and usage of departments   The basic syntax is: Select... from tablename start with cond1 Connect by cond2 Where cond3; Simply put, a tree structure is stored in a

The project requires Oracle + Entity Framework + WCF Ria service + silverlight4.0 to build a development framework. For the first time, I decided to write down these things. It is very important for me to be forgetful. Review the efforts of the week

On September February 3, 2010, I found that I used toad to directly import data from Oracle databases.Access is not possible. In order to import data into access using indirect channels from toad. You can use text files or XLS files. In fact, what