Oracle

Oracle's ALTER TABLE Drop COL is specifically internal to the data storage block operation, and if a tool such as Dul is recoverable after the drop COL, I will illustrate the problem with a specific test, combined with bbed,dump block. 1. Create a

Action class Using System;Using System.Data;Using System.Configuration;Using System.Data.OracleClient;Using System.Text;Using System.Windows.Forms;Using System.Xml;Using Transactions;DB Summary description written by Luos.luo, the creator of

Oracle inversion inversion function Oracle provides a reverse inversion function reverse, but this function cannot be grouped upside down, this article provides a function that can be grouped upside down, as follows: CREATE OR REPLACE FUNCTION

When we use a database, we always want the contents of the database to be reliable and correct, but because of the calculation Failure of the machine system (including machine failure, media failure, misoperation, etc.), the database may sometimes

Method: The code is as follows Copy Code GROUP BY XX has count (*) >1,rowid,distinct,temporary table,procedure The following statement can query that the data is duplicated: The code is as follows

A stored procedureFirst, we set up a simple table for the test of stored procedures The code is as follows Copy Code CreateTableXuesheng (ID integer, xing_ming varchar2 (), Yu_wen number, shu_xue number);Insertinto

Client Windows blue screen, and then the customer in the computer a random delete, really cold. Oracle failed to start and reported ora-01172,01151 error. Processing process: The code is as follows Copy Code Microsoft

A simple case expression that uses an expression to determine the return value. Grammar: The code is as follows Copy Code Case Search_expressionWhen Expression1 THEN RESULT1When Expression2 THEN result2...When

An example of using the LAG analysis function to set the repeating field to null is as follows: The data for the test table test_xx are as follows: To achieve the following output results: The test SQL statement is The code is as

We know that when Standby_file_management is set to auto, if the primary library creates a new Datafile,standby, it automatically synchronizes a new datafile; but when primary Rename a datafile, although Standby_file_management is set to

The exception is as follows: Java.lang.ClassNotFoundException:oracle.jdbc.driver.OracleDriverAt Java.net.urlclassloader$1.run (urlclassloader.java:200)At Java.security.AccessController.doPrivileged (Native method)At Java.net.URLClassLoader.findClass

The article provides the database tutorial the connection code is an ASP tutorial. NET and Oracle,sql server,access database class Oh, if you're a asp.net tutorial developer then you're cool, this is a. NET can be used with the Oracle,sql server ,

1. Automatic growth of data type processing MySQL has an automatically growing data type, and the data value is automatically obtained when you insert a record without manipulating this field. Oracle does not have an automatically growing data

Oracle Modify Field Name ALTER TABLE XGJ Rename column old_name to new_name;Modify a field type ALTER TABLE tablename Modify (column datatype [default value][null/not null],....);Example Assuming table xgj, there is a field name, data type char (2

6.lpad,rpadFunction: The left/right string fills some specific charactersSyntax: Lpad (String, n, [pad_string])String: But the character or argumentN: The length of the character, is the number of strings returned, if this number is shorter than the

Oracle dul 11 has finally been released. You can't wait to download it for testing. The current version is dul 11.2.0.0.1. Currently, only for linux is released, and other versions are expected to be released.Oracle dul 11 releasedDul-11.2Oracle-dul-

A friend's company's database encountered an exception and there was no backup. After the database is opened, crash will be quickly cleared. The following alert log information:Tue Jul 08 22:53:03 2014SMON: enabling cache recovery[2, 13803]

If you need to reprint it, please indicate the source!Anyone who has used ORACLE knows that it is very cumbersome to change the column name and sequence of tables in ORACLE. Here is a simple method.SQL> select object_id from all_objects where owner =

Test hardware description:The test uses my machine. The configuration is as follows:CPU: C433Memory: 128 MBHard disk: Cool 2 generation 20GTest Software description:Windows nt server4, sp5, apache 1.3.12, php3.0.15, php4rc1, mysql 3.22.29, and