Oracle

The multi-level tree structure of RM uses Oracle connect by for sorting and adds layer-level sorting. Connect Select T. ID, T. curname, T. parent_id, T. order_value from tb_company t where status = 1 and T. ID in(Select distinct r2.company _ id from

Differences between Oracle exp query statements in Windows and Linux 09:54:15 let me say something Add to favorites I want to contribute Today, due to business needs, we ran exp conditional export and found some differences

// Create a spatial field index for Oracle Spatial table// ================================================Drop index index_sp_v_gbjj;Drop index index_sp_v_xzq;Drop index index_sp_v_ytfq;Drop index index_sp_v_dltb;Drop index

In the transaction per second system, Oracle TimesTen memory database and BEA's WebLogic realtime are two secrets. 1. Oracle TimesTenOracle TimesTen is a memory database acquired by Oracle. No matter how the Oracle SQL statements are optimized, the

Recently I made a data diagnosis project, in which I wrote a database operation class, including connecting to the database, reading data tables, performing SQL operations, and releasing the database. I hope it will be useful to everyone, due to the

[Oracle entry series] Chapter 2 _ database query basics -- v512 workshop Editor: Xuan Yu Null Value Field alias Join Operator   Send me an email Sort Conditional Query Relational operators V512 Studio

Oracle system functionsOverview:Sys_context ('userenv', 'param') function: this function can be used to query important information.For example, which database are you using?Note: 1)Host: Returns the name of the host where the database is

Oracle Stored Procedure return result set * Process return record set: Create or replace package pkg_test As Type myrctype is ref cursor; Procedure get (p_id number, p_rc out myrctype ); End pkg_test; / Create or replace package body

1. conversion functionsThe biggest relationship with the date operation is the two conversion functions: to_date (), to_char ()To_date () converts the character type to the date type in a certain format:Specific usage: to_date ('1970-11-27 ',

Case study: There are two Oracle databases A and B, both of which are 10 Gb. How many pieces of data of one table in database a need to be inserted into one table in database B? After checking on the Internet, you can create dblink on server a. Of

For example, if you want to query records with identical names, ID card numbers, and addresses in a personnel table (table name: peosons), select P1. * from persons P1, persons P2 where p1.id <> p2.id and p1.cardid = p2.cardid and p1.pname =

Oracle Data Import currently uses the following two types: 1. Use SQL * loader to import txt or CSV data to Oracle; 2. Create two dblink Oracle databases to export data to each other;   Data Import problems: 1. Oracle dblink access lob field ORA-2299

Oracle databases have three standard backup methods: Export/Import (exp/IMP), hot backup, and cold backup. Exporting backup is a logical backup, while cold backup and hot backup are physical backup. 1. Export/import (export/import) The export can be

Oracle databases have the following data types: sclare, composite, and reference ).1. scalar (char, number, varchar2, long, clob, blob, nclob, bfile, date) Char (Num) is a fixed length of up to 2000 characters. The query efficiency of char is

Today, Oracle SQL plus performed the delete and query operations and then the query operations in PL/SQL. The results of the same statements were different, which made me feel quite depressed, later, I suddenly thought it may be caused by

Environment Oracle 11.2.0 + SQL plus + powerdesigner 15.1  Problem A course design is required to study Oracle database application technology this semester. Powerdesigner exports SQL and imports to Oracle to query the table structure with the

1. What is a ckpt process?   Purpose: Send a signal to dbwn Update Data File Header Update Control File   At specific times, all modified databasebuffers in the system global area are written to the datafiles by dbwn. thisevent is called a

1. When using Oracle, Oracle can run normally by starting oracleservicemyorcl and oracleoradb11g_home1tnslistener; 2. To allow hosts on the LAN to access your Oracle database, you must start the oracleora81homemanagermentserver service. Note: myorcl

Environment: oracle11g + ie9 Problem: the Oracle Database Control browser cannot log on Solution: Open your browser and enter URL: https: // 127.0.0.1: 1158/EM or https: // localhost: 1158/em If Internet Explorer cannot display the webpage appears,

I. Environment Description   Redhat Enterprise Linux 6.0 + virtual box 4.1.8 + Oracle 10g  2. Pre-installation Configuration  1. install the software packages required for Oracle 10g r2 Use Root Log on to the system and install the following