Oracle

Take oracle in Unix as an example.1. Check the SQL statement currently executed by the sessionRun the TOP command to check the CPU usage of the Oracle service process. Generally, the CPU usage of a single process should not exceed 5%. If the CPU

Today, the customer suddenly wants to modify a large amount of data, so he has to look at how to import the data in Excel to Oracle. Now the steps are briefly recorded as follows (refer to the relevant onlineArticle): 1. Prepare data: Create

// Implement an automatic value-added column in Oracle -- 1. create Table users (userid int primary key, -- User ID username varchar (20), -- User Name passwd varchar (20), email varchar (30), grade INT ); -- user level -- 2. create sequence userid_

If you change the IP address, you need to re-create em. The following is the EM command: Create an EM DatabaseEmca-repos createRebuilding an EM DatabaseEmca-repos recreateDelete An EM DatabaseEmca-repos dropConfigure Database Control for the

During project creation, Oracle database migration may occur, and the sequence may be reset. As a result, when the current value of the sequence is smaller than the maximum value of the field in the table using the sequence, an error occurs,

EXP-00091: Exporting problematic statistics .. . Exporting table wf_general export EXP-00091: Exporting problematic statistics .. . Export table wf_plan_book export EXP-00091: Exporting problematic statistics .. . Exporting the table

We know that the Oracle client supports setting the nls_lang parameter. The setting of the nls_lang parameter varies with the system platform. This article first introduces the composition of the nls_lang parameter, and then introduces the settings

From: http://www.cnblogs.com/jevonsea/archive/2009/07/30/1535492.html Today, we need to store all the space data in the station into the database. Therefore, we have installed oracle on the server and need to connect it locally. We checked the

Alter user Scott account unlock; -- Unlock Scott userSelect * from Scott. EMP where to_char (hiredate, 'yyyy-mm-dd')> '2014-1-1 '; -- date comparisonSelect * from Scott. EMP where to_char (hiredate, 'yyyy') = '000000'; -- the start time year is 1980.

Manage permissions and Roles * IntroductionWhen you create a user, the user does not have any permissions and cannot perform any operations. If you want to perform a specific database operation, you must grant the system permissions to the user; if

Basic PL/SQL 1. PL/SQL concepts PL/SQL (Procedural Language/SQL) is an extension of Oracle in the standard SQL language. PL/SQL not only allows embedding SQL languages, but also defines variables and constants, allows the use of conditional

Data AdministratorEach Oracle database should have at least one Database Administrator (DBA). For a small database, one DBA is enough, but for a large database, multiple DBAs may be required to assume different management responsibilities.*

Oracle Complex Query * Use subqueries in the from clause . Display information of employees higher than the average salary of their own departments. // 1. query the average salary and department number of each department, select deptno, AVG (SAL)

Oracle does not set an auto-incrementing primary key. If you want to implement the auto_increment function of databases such as MySQL, you need to create a sequence.   1. Define the primary key as the automatic growth identifier type In MySQL, if

1. Set linesize 100; set the length 2. Set pagesize 30; set the number of entries displayed on each page 3. Open the notepad ed F: \ soft \ key.txt in Ed a. SQL, which indicates opening the file on drive F. If it does not exist, you will be prompted

  First install the tool and then connect VPN:IP: 113.108.186.130User: jfwh_qujyPassword: qujy0429 VPN, Click the gray connection VPN in the second picture. the user name and password are also available here. Linux Server:IP:

Jar files: Mysql-connector-java-5.1.7-bin.jar (* http://dev.mysql.com/downloads/connector/j/5.1.html of main files) Commons-dbutils-1.1.jar (queryrunner package http://commons.apache.org/downloads/download_dbutils.cgi required) Instance: 1. Put the

SQL statement for time field query: Select * From mycontent t where T. create_date SQL statement for modifying the time field: Update mycontent tSet T. create_date = to_date ('2017. 2012 13:10:45 ','Yyyy-mm-dd hh24: MI: ss '),T. modify_date =

1. Tomcat official website Documentation Reference http://tomcat.apache.org/tomcat-6.0-doc/jndi-datasource-examples-howto.html 2. test: Add the following code to Tomcat context. xml: Generally, it is in the \ conf \ directory of the tomcat

Normal login with sqlplus When PLSQL is used, when the same user logs on to the same database An error is reported: Initialization errorSQL * Net is not fully installedOraclehomekey: Software/OracleOraclehomedir Specific Configuration: In PLSQL