Oracle

Syntax for adding fields: ALTER TABLE tablename Add (column datatype [default value][null/not null],....); Modify the syntax of the field: ALTER TABLE tablename modify (column datatype [default value][null/not null],....); Syntax for deleting a

Direct titleView the current database schema Connect into the database, type the following command: Copy Code code as follows: sql> archive log list; You can view the mode of the current database, and if the database log mode

An Oracle cursor is divided into a display cursor and an implicit cursor. Display cursor (Explicit Cursor): A cursor defined in a PL/SQL program, used for querying, is called a display cursor. Implicit cursors (implicit Cursor): A cursor that is

Test hardware Instructions: The test used is my love machine, configured as follows: cpu:c433 Memory: 128M Hard drive: Cool fish 2 generation 20G Test Software Description: WIN32 is under Windows NT Server4,sp5,apache 1.3.12,php3.0.15 and

Importing and exporting Oracle scenarios is the main theme of backup and recovery, not DBAs, and there's not much research on importing and exporting data, just a little bit of experience in the process of using it. Import Copy Code code

1. Get database name and date createdSELECT name, created, Log_mode, open_mode from V$database; 2, the Oracle database computer host name, Oracle database instance name and Oracle Database management system version informationSELECT host_name,

The schematic diagram is as follows: Control file: A file (the most important file) used to control how data is imported. Parameter file (optional) Data files: Flat file where source data is placed Error files: Putting data that cannot be

1, in the report page layout corresponding position to add a text box, generally for download Right-click the Pl/sql Editor to write a hyperlink and add the following: Copy Code code as follows: Function B_13formattrigger Return

In the afternoon learning Oracle 10g R2 Concepts Leave a pen here. The unit in which Oracle manages storage space in the database data file (datafile) is the data block. A block of data is the smallest (logical) unit of data in a database. The

Many data conversion processing operations encounter the need to convert 0.007007040000 to 0.7%, and we use Oracle's SQL function To_char to implement this transformation. This function is used to convert a date or Number data type to a string that

This article describes the substitution of SQL Server, Oracle, and MySQL for null-detected values. What happens when SQL Server Oracle MySQL detects that a value is null in the database? 1, Mssql:isnull ()Grammar Java code Copy Code code as

Let's start with some of the scripts we use to back up and restore Oracle databases directly using commands Oracle Data Backup: Step 1 Back up the user data. 1. Connect the Linux terminal using the database administrator account under Linux system. 2

Tables can be divided into range, hash, list, and table partitions, and the indexes on them are different from the indexes on the normal table, and Oracle has 2 categories of indexes on the partition table, namely Local index and global index, the

The syntax structure of the DECODE function is as follows: Copy Code code as follows: Decode (expression, search_1, result_1) Decode (expression, search_1, Result_1, search_2, result_2) Decode (expression, search_1, Result_1,

The Recycle Bin (recycle) is, in principle, a data dictionary table that places the database object information that the user deletes (drop). The object that the user is deleting is not deleted by the database and still takes up space. Unless the

I used to connect remote oracle8.0.5 for NT Enterprise version with PHP, not with Odbc,oracle interface. I'm too desperate! Looking for, and finally found the right way to connect, I use the OCI Interface, ODBC and Oracle or not to find%m epiphyseal?

Oracle databases support materialized views-not virtual tables based on base tables, but based on actual tables that are actually present in a table-materialized views are stored on nonvolatile storage devices.The following experiment creates the

Oracle will not say, Linux is CentOS.1. Install httpd (Apache)Yum Install Httpd-y 2. Install PHP, PHP-GD, Php-mcrypt, php-pecl*Yum install php php-gd php-mcrypt php-pecl*-y 3. Install Oci8PECL Install Oci8Enter Oracle installation directory at

I. Import an Excel file using the PL/SQL Import Tool 1. Open PL/SQL and click T00ls->odbc in the menu bar Imtorper, open the ODBC Importer option box; 2. In the Data fromodbc page, select the format of the file you want to import, and select

--Creating profile profilesCreate Profile profile123 LimitFailed_login_attempts 2;--Modify the profile of the userAlter user Scott profile profile123;Ensure that the initialization parameter resource_limit is set to true to enforce resource limits