Oracle

-- Obtain the table primary key and typeSelect acc. column_name, ATC. data_typeFrom all_constraints AC, all_cons_columns ACC, all_tab_columns ATCWhere AC. table_name = upper ('table name ')And AC. constraint_type = 'P'And AC. constraint_name = acc.

Install the Oracle Instant Client in windows and use PL/SQL developer. Test System: Windows 7 Home Basic. (1) install Oracle Instant Client For installation of Oracle Instant Client, see post http://blog.csdn.net/zklth/article/details/7190035

There are two tables: update the Val value of the row with the same ID value in Table tab1 and that in Table tab2 to the Val value in table 2.Select * From tab1; Select * From tab2 The most common mistake is: Update tab1 set val =

The following is the official Oracle Database, which is listed here. We hope to reduce the search time. Download it now ~ Oracle Database 11g Release 1 (11.1.0.6.0) Standard Edition, Standard Edition one, and Enterprise Edition

The temporary and undo files of the database do not need to be backed up. They can be restored after they are lost, and data will not be lost. 1. After files in the temporary tablespace are lost, they are automatically created after the database is

1. Set SSH tunnel on putty of localhost, for example: In this way, the port 1511 connecting to the local machine will be forwarded to port 1521 of remoteip. Click "add", and then log on to the remoteip through SSH. The sshtunnel is created. On

Document directory Application Analysis of indexes in Oracle Application Analysis of indexes in Oracle Indexing is the most effective way to improve data query and the most difficult technology to master, because correct indexing may increase the

In Oracle 9i, reading char fields is inconvenient, which limits the use of char fields. to read the value of a field, use the following methods:   SQL> Create Table Test ( 2 a char (5 )) 3 tablespace users;   The table has been

If not exists (select * From DBO. sysobjects where id = object_id (n' [DBO]. [tablespaceinfo] ') and objectproperty (ID, n' isusertable') = 1) Create Table tablespaceinfo -- create a temporary table(Nameinfo varchar (50), -- table nameRowsinfo int, -

1. Use the thin driver in client software development In terms of Java software development, Oracle database provides four types of drivers, two types of client software for application software, applets, Servlets, and so on, the other two types are

Let's first use a small table to explain which aspects should be paid attention to in the Oracle execution plan. HR @ orcl> set autotrace traceonlyhr @ orcl> select * from t; when fuzzy comparison of the two SQL statements, we recommend that you

(I) direct path loading and buffer cache Data inserted in the direct path is directly formatted as an oracle block from PGA without passing through the buffer cache. Then, a common ORACLE Server process writes data blocks to data files. Dbwn is not

(I) A table has many duplicate values in a column. The base is very small. What indexes should be created? -- Create a bitmap index. For details, see the comparison of the lock costs between B-tree indexes and bitmap indexes. For example: Create

MySQL replication and Oracle logical standby are both SQL apply. What is the difference in implementation?Binary log and redo transmission principlesMySQL replication can be easily used for application read expansion, and can also help MySQL

This case takes China Construction Bank as an example.Download the created transaction table and name it ccb.txt.At this time, you have two options: sqlldr or external table   (I) sqlldrBecause online banking can only be used on win, if your OS is

Differences between Oracle database and MySQL database: 1. Group function usage rules In MySQL, group functions can be used at will in select statements. However, if a group function exists in a query statement in Oracle, other column names must

I encountered a lot of trouble when I recently used Oracle to import and export data! Then I carefully studied the Oracle database and summarized several command methods for import and export for future reference.Data export:1. Export the database

I have seen many people talking about issues such as TNS or the inability to log on to the database. I just summarized the following.First, the network structure of Oracle can be combined with encryption, LDAP, and so on .. We will not discuss it

1. View)1.1 conceptsView ----- is a "logical table \" defined by the SELECT query statement (which can be a single table or multi-Table query). Only definitions are defined without data, is a \ "virtual table \". when creating a view, you only save

Oracle may be the most widely used database in the world. At least in my projects, Oracle database applications account for half of the total. It can be said that in the past few decades, the front-end and business-layer technologies have changed,