Oracle

1. If the console is not installed on the database machine or the network service name is not configured using the console. You can log on to the idle process on the server by running the command sqlplus sys/sys as sysdba. See step 4. 2. If the

Differences: 1. Primary keys. Oracle cannot implement auto-increment, and MySQL can implement auto-increment. Oracle new sequence, seq_user_id.nextval 2. Index: MySQL index starts from 0 and Oracle starts from 1. 3. Paging, MySQL: Select *

Delete an Oracle database in a Linux operating system in detail: 1. Disable ORACLE Server and background processesPS-Ef | grep oraTurn off the databaseShutdown immediate 2. Disable the listener.LSNRCTL statusIf it is enabled, execute LSNRCTL

If you delete a piece of data in the table in Oracle, you can also perform rollback through the rollback operation (rollback). If you want to clear a piece of data If you do not want to perform rollback on the table data, you can immediately

Copy codeThe Code is as follows: create or replace procedure procsendemail (P_TXT VARCHAR2, P_SUB VARCHAR2, P_SENDOR VARCHAR2, P_RECEIVER VARCHAR2, P_SERVER VARCHAR2, P_PORT number default 25, P_NEED_SMTP int default 0, P_USER VARCHAR2 default null,

In layman's terms: The number of records connected by A left join B is the same as that of Table. The number of records connected by A right join B is the same as that of Table B. A left join B is equivalent to B right join Table: Field_K, Field_A 1

When you use start with connect by nocycle prior When performing recursive data search, the performance of the following two sections of code must be significantly different. For more information, please note that the code can be directly summarized

I. Solution to garbled buttons in oracle em: 1. Modify the font of jdk. Copy codeThe Code is as follows: [oracle @ esop db_1] $ cd $ ORACLE_HOME/jdk/jre/lib/ [Oracle @ esop lib] $ mv font. properties font. properties_bak [Oracle @ esop lib] $ cp

Requirement: Currently, due to the large number of transaction records in the business system, some supervisors often need to see all the records, but do not want to scroll. They can see all the records at a glance, so I thought of the form of

At the end of last year, a lot of system data migration was conducted. Most of the systems performed logical migration due to platform and version reasons. A few of them performed physical migration and some experiences were made, share with

Table query: Merge query: Use the union keyword to remove duplicate rows that meet the condition. Copy codeThe Code is as follows: select ename, sal, job from emp where sal> 2500 union select ename, sal, job from emp where job = 'manager '; Union

1. First create a directory: Create directory name as 'a directory on the database server ', for example:Create directory alias as 'd: \ Server directory name ';Put the imported or exported files in this directory. 2. Export and Import Take SID =

Sometimes it is unclear that all the values allowed for some parameters can be obtained by the following two methods: 1. directly enter the error value and let the error prompt Copy codeThe Code is as follows: SQL> alter system set "_

Connect to Idle Instance Step 1 View Oracle_SID. [Oracle @ linuxserver ~] $ Echo $ ORACLE_SID Cjdl The SID here must be the same as that in the initialization file spfilecjdl. ora. [Oracle @ linuxserver ~] $ Cd $ ORACLE_HOME [Oracle @

The distinct keyword can only be used to filter all records in the query field that are the same (the record set is the same). If you want to specify a field, it does not work. In addition, the distinct keyword is sorted, Which is

The company needs to process some reports and use percentages to keep 2 decimal places. Only the round and trunc functions can be used to implement (round (_ data, 2), but the format is not neat, you can use round if the format is not rigorous. I

In this article, the B-tree (B-tree) Hash k-d tree (k-d tree) Point Quadtree (Point Quadtree) This article describes the structure of Oracle indexes. You can understand the underlying data structure of Oracle indexes to better understand the

Receive the contract_no and item_no values and search for them in the inventory table. If the product: Delivered, assigned in arrival_date as the 7 days after today Ordered. In arrival_date, the value is assigned to the month after today. If there

The ora 12154 error is reported when plsql is connected to the oracle database. Today I encountered a problem that sqlplus can be used to connect to a remote database, but plsql cannot be used to connect, error "ORA-12154: TNS: Unable to parse the

When deleting a user in Oracle, the following statement is prompted: ORACLE cannot delete the current connected user: SQL codeSQL>Copy codeThe Code is as follows: select username, sid, serial # from v $ session; Username sid serial #-------------