Oracle

SQL statements related to modifying the table structure in Oracle 9i1. Add a column:Alter table table name Add (column name data type );For example:Alter table emp add (weight number (38,0 )); 2. Modify the Data Type of a column (generally, the

Usage of the count function in Oracle Count is used to count the number of records in the query results. Example Table t_test Name Gender Age Salary Zhang San Male 23 2000 Li Si

Problem description: update other data tables based on the data in the col2 column in tablea, and change col2 from 0 to 1. To increase the query speed, the function-based index is used for col2 in Table A. Now nested cursors are used to update col2

In the morning, the customer needs to export the full path of some records and records in the category (for example, table A is the master table, table B is the category, and a foreign key sort_id is associated with B, B In addition to the ID and

Description: Now there are two systems. One major system uses Oracle, which is called oracleproject. Another system uses SQL Server, which is called sqlserverproject. Now you need to synchronize their data. The primary database is Oracle, and SQL

Use Java to write Oracle stored procedures Bromon originality, please respect copyright We usually use PS/SQL to write stored procedures for Oracle. From Oracle 8, we can have another option: Java. Starting from 8.0, Oracle had a built-in JVM with

For example, after having suffered a lot of losses from Nn, I am determined to write this article. I would like to sum up the experience of uploading slice. The type may be incorrect. I believe everyone understands it. I just want to write down my

1. Use % 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 column type of the Students table is varchar2 (20),

Oracle databases have two backup methods. The first type is physical backup. This method enables complete database recovery, but the database must run in the recovery mode (the business database runs in the non-recovery mode ), this method requires

Optimizer for PL/SQL statement execution in Oracle databases, including cost-based optimizer (CBO) and rule-based optimizer (RBO ). The RBO optimization method depends on a set of strict syntax rules, as long as the statements written according to

Optimizer for PL/SQL statement execution in Oracle databases, including cost-based optimizer (CBO) and rule-based optimizer (RBO ). The RBO optimization method depends on a set of strict syntax rules, as long as the statements written according to

Since Oracle does not provide tools for Real-Time Message output, Oracle database developers always have to face the challenge of real-time monitoring of their reserve process execution. They must use dbms_output.put_line to call and return the

  The permission control in win7 is indeed good, but sometimes it is hard to understand. Today, an Oracle database is installed on an XP Server, and an Oracle client is installed on my win7 server. The configuration is successful, but PL/SQL cannot

There are two methods to create a database in Oracle.First, use the Oracle database creation tool dbcaThis is a graphic interface that is easy to use and easy to understand, because of its friendly interface, beautiful appearance, and complete

Check an online article to display the list of events from 10000 to 10999, I want to see if there is another one, so I will slightly modify it, from 0 to 20000, and export it to the oracle.txt file.   Set linesize 120Set feedback offSet serveroutput

Symptoms: When Oracle 10g is installed, the network detection fails. If no processing is performed, the installation continues and the IP address is not specified. After iporacledbconsole is modified for the machine, it cannot be started, view the

A few days ago, my machine was installed with Oracle 10 Gb again. Ah, since it was the first two years, it was very slow to start. It was finally started in about 8 to 10 minutes, after using EM, I thought it was not very good. I installed the

Db_name: Unique identifier of a database (Oracle database. This expression is sufficient for a single database, but with the popularization of distributed databases composed of multiple databases, this method of Command database creates a certain

View the current license status SQL> show parameter license;NAME TYPE VALUE------------------------------------ ----------- ------------------------------license_max_sessions integer

Waiting event category: ========================================================== ========================================================== ==================================== Administrative: Wait for the user to wait for the DBA command