Oracle

  If you want to query all the tables in the database, you can querySelect * From dba_tables If you want to query the tables of a user in the database, you can also log on to the user and then query:Select * From user_tables   To import External

Http://database.51cto.com/art/201011/233370.htm   When the MySQL database does not meet our large demand, we need to migrate the data in the MySQL database to the Oracle database. In this process, some problems are worth noting. AD:

Recently, I searched many online examples of spring operations on Oracle internal objects, basically introducing the calling of the stored procedure ~ There are not many articles about directly calling Oracle internal functions ~ Here, Pharaoh draws

Source: http://blog.csdn.net/zgh2003/archive/2007/03/16/1531774.aspx In recent times, many netizens raised questions about Listener Configuration, and the client cannot connect to the server ). This article briefly introduces the Listener

Aggregate functions:Count sum max min avgCount the number of rows in the returned result setSum max min avg. However, the aggregate function emphasizes "result set ...... ", EmphasizedThe current operation object is the result set.Note that NULL

Exercise 5 1. display the name, Department number, and department name (dname) of all employees ). EMP and dept. Both tables have the deptno field. Select ename "employee name", D. deptno "department no.", D. dname from emp e, DEPT d Where E. deptno

Note: orcl is the default database when oralcle is installed, and orcldb is the database that you added later. Tnsnames. ora and listener. ora are prepared as follows: # Tnsnames. ora network configuration file: D: \ oracle \ product \ 10.2.0 \ db_1

1. query the user's connection statusSelect username, sid, serial # from v $ session where username = 'maximo '; Username sid serial #--------------------------------------------------MAXOMO 22 1MAXIMO 142 1   2. delete one by oneAlter system kill

1. Select* From EMP; 2. Select empno, ename, job from EMP; 3. Select empno number, ename name, jobWorkFrom EMP; 4. Select job from EMP; 5. Select distinct job from EMP; 6. Select distinct empno, job from EMP;Note: Because employee numbers are not

Correspondence between access, SQL Server, and Oracle Data Types The table below shows the ADO data type mapping between access, SQL Server, and Oracle: Datatype Enum Value Access Sqlserver Oracle Adbigint 20  

SQL definition: SQL is a general data processing language specification for databases. It can perform the following functions: extract and query data, insert and modify data, and delete data, and generate and modify database objects, database

1. delete a tablespace Drop tablespace TableSpaceName [including contents [and datafiles]2. delete a user Drop user User_Name CASCADE3. Notes for deleting a table When deleting all data in a TABLE, the truncate table name must be used. Because when

-- First, check whether there are CTXSYS users and CTXAPP roles in the database. -- If you do not have this user or role, it means that the intermedia function is not installed at the time of database creation. -- You must modify the database to

  To install Oracle, Familiarize yourself with and learn about oracle in advance. Your own system is Windows 7 flagship edition, When installing Oracle 11g Enterprise Edition, The following error is prompted during the "product-specific

Make sure that the directory where the installation file is located does not contain Chinese characters, otherwise there will be various problems! Since it is a learning and testing environment, these two items are free. Next, ignore. Of course, we

Preface If we have some experience in starting and stopping databases, we always think that there is only one command. However, I have seen a book with more than 100 pages dedicated to the operation process after the command. Let's just talk a

Note: The answer is after the option Q. 1: The default tablespace clause in the create user command sets the location　　1. Database Objects created by the user2. Temporary Objects Created By the User3. System Objects Created by the user4. None of

Chapter 4 of oracle parameter 2 This topic describes common parameters. AUDIT_FILE_DESTParameter type: StringSyntax: AUDIT_FILE_DEST = 'directory'Default Value: ORACLE_HOME/rdbms/auditParameter category: staticAUDIT_FILE_DEST defines the path for

31. Forced index failure   If two or more indexes have the same level, you can force the ORACLE optimizer to use one of them (using it, the number of retrieved records is small ).   Example: SELECT ENAME FROM EMP Where empno = 7935 And deptno + 0 =

4.Select the most efficient table name sequence (Valid only in the rule-based Optimizer) ORACLEThe parser processes FROMTable name in the clauseTherefore, the base table driving table written in the FROM clause will be processed first. when the