Oracle

The show_space version has many versions on the network. A general version is compiled today and will be used later.   Create or replace procedure show_space (v_segment_name in varchar2, Region in varchar2 Default User, v_segment_type in varchar2

1. offline data files or tablespaces (In archivelog mode) Alter database and alter tablespace offline 1) offline data files 1. offline data files Alter database datafile 'd: \ oracle \ oradata \ xm01.dbf' offline; 2. Copy (MOVE) data files Copy

First, let's explain the concept of a database. A database is a file stored on a disk. The data stored in these files has a certain physical and logical structure. Database NameIs the name of the database, such as myoracle, which is generally only

1. Two Ways to delete table dataA. Delete * From my_table;B. truncate table my_table; 2. Delete the entire tableDrop table my_table; How can we recover tables accidentally dropped? In fact, Oracle also has a similar "recycle bin" For example, you

operator description Union all returns all the rows retrieved by the queries, including duplicate rows. Union returns all non-duplicate rows retrieved by the

The types of Oracle Data Dictionary views are user, all, and DBA. User _ *: Information about objects owned by users, that is, information about objects created by users All _ *: Information about objects accessible to users, that is,

The preparedstatement.exe cutebatch method calls a void executeforrows method at the underlying layer for execution. They are very lazy. to reuse this method, they lose the returned value, therefore, you cannot know what the current statement

ODBC   New Version Driver = {Microsoft ODBC for Oracle}; server = myserveraddress; uid = myusername; Pwd = mypassword;     Old Version

1. Remove the double quotation marks in the SQL statement generated by Oracle.When you use powerdesigner to export a table creation SQL statement for the Orale database, double quotation marks are added to the table name and field name by default,

1 utl_file_dir Parameter Definition Utl_file_dir is a "static parameter" in Oracle. You can set one or more paths. It is used to specify the path when file I/O operations (utl_file package can be used) are performed in PL/SQL. Utl_file_dir is a

1. Clone Process [Oracle @ cent4 ~] $ Dbca 1. After running dbca, select "manage template ". 2. Select "create from existing database (structure and data" 3. Select the name of the instance to be cloned. 4. Enter the Template Name and description"

To add sub-partitions for an existing partition (such as clah_201110), we can only add them one by one. It is very troublesome. The following code. I wonder if you have any good solutions. Of course, you can add partitions and subpartitions together

1. Use SQL * Plus to stop a database 1.1 stop an instance [Oracle @ standby1 ~] $ Sqlplus/nolog SQL * Plus: Release 10.2.0.1.0-production on Wednesday June 11 17:53:02 2008 Copyright (c) 1982,200 5, Oracle. All rights reserved. SQL> Conn/As

Public is not a role. You can understand it as a set of all database users.If a permission is granted to the public, the database user can have this permission (of course, some users may not have the connect permission ).For example, if you want to

After establishing an Oracle database, you must properly configure the listener and Network Service name before your application can access our database. Therefore, listeners must be configured on the server, and network service names can be

When you retrieve data from Oracle database, When some records has null value in some columns, If you want to display the records more meaningful, With the columns whose value is null being displayed with a meaningful string, You can turn help

Here is an example:   Prepare data: Create Table fruit ( ID number (4) primary key, Name varchar2 (150) );   Insert into fruit (ID, name) values (1, 'apple ');Insert into fruit (ID, name) values (2, 'bana ');Insert into fruit (ID, name) values (3,

This article Reprinted from: http://blog.csdn.net/mantisxf/article/details/1695441 For personal learning and improvement only.   Oracle syntax over (partition ..) Select * from test Data:A B C1 1 11 2 21 3 32 2 53 4 6 --- Add the C column

The following constraints are listed in detail: 1. Primary Key constraints:To add a primary key constraint to a column, this column must meet the condition that it is left empty.Because of the primary key constraint: A column is restricted, and the

The most common varcher2 type in Oracle can store a maximum of 4000 bytes of content. Generally, this type can meet your needs. However, in some special cases (for example, if the image or content to be stored exceeds 4000 bytes), varcher2 cannot