Oracle

% TYPE and % ROWTYPE in Oracle 1. Using % TYPE www.2cto.com in many cases, variables should have the same TYPE as columns. For example, if the name column type of the emp table is VARCHAR2 (20), we can DECLARE a variable: DECLARE var_Name VARCHAR2 (2

Oracle notes: Tables and fields (3) 4. change the field name, size, TYPE, and so on: Change the name: www.2cto.com alter table mytable rename (OLD_FIELD) TO (NEW_FIELD); size and TYPE: alter table mytable modify FIELD_NAME TYPE (LENGTH ); where:

As a DBA, the summary of oracle zone management and segment space management is one of the common scenarios: Creating tablespaces: www.2cto.com [SQL] create tablespace Think datafile '/u01/app/oracle/oradata/orcl/think. dbf 'size 100 M autoextend on

Some time ago, someone asked me about the order adjustment of table fields in the database. First, there is no bad impact on the database. Second, there is no simple method or tool to solve this problem. Www.2cto.com is a common problem for most

When parsing oracle rownum, I recently used oracle rownum for paging display, and made further analysis and research on rownum. This is summarized as follows, hoping to benefit everyone. For rownum, www.2cto.com is the number of the row returned

Oracle group by test statement SQL code www.2cto.com create table test (a VARCHAR2 (20), B VARCHAR2 (20), c NUMBER, d VARCHAR2 (20 )) insert into test VALUES ('a1', 'b1', 1, 'T'); insert into test VALUES ('a3', 'b3', 3, 'T '); insert into test

The first reason for this error is that the session and process connections are full. view the number of sessions and processes at www.2cto.com: select count (1) from v $ session; select count (1) from v $ process; display the maximum value of

The sequence is cleared early every morning, so that the sequence starts from 1 every day. job: www.2cto.com SQL code begin sys. dbms_job.submit (job =>: job, what => 'clearseq (''seq _ SN_ID ''); ', next_date => to_date ('16-10-2012 18:37:20 ', 'dd-

Custom oracle throws an exception to solve database exceptions throw Caused by: java. SQL. SQLException: ORA-02291: violation of complete constraints (xxx. FK_yyyy)-the parent keyword www.2cto.com is not found. How can I customize the exception

How can we use the oracle keyword as the field name? What should we do when we define the field name and alias with the same name as the oracle keyword? In fact, it is very simple. Just add "", such as "group" www.2cto.com here to see the following

Introduction to parallel execution in Oracle 1. The concept of parallel execution is to physically divide a large serial task into several smaller parts, which can be processed simultaneously. This is like building a house. There are some things

Oracle LAN connected to the database today is connected to the local area database, the problem can be said to be a variety of problems, so I want to share with you here, I am the first time to use the oracle database, so it is relatively unfamiliar,

1. Declare the package www.2cto.com 01 createorreplacepackage TAL_TESTis02 03 -- Author: ADMINISTRATOR04 -- Created: 15: 15: 3805 -- Purpose: XXXX test 06 07 TYPE myCursorTypeISREFCURSOR; 08 09 -- Test empty cursor; 11 12endTAL_TEST; 2. Package 01

The trim function in oracle is used to delete the given characters in the header or tail of a given string or given number. The trim function has the following form: www.2cto.com trim ([leading/trailing/both] [matching string or value] [from]

Partition index causes database paging disorder select t2. * from (select t1. *, rownum rn from (select * from tb_courseinfo orderDatatime desc) t1 where rownum 100 www.2cto.com may be retrieved due to repeated datatime numbers. There are two

Special characters in SQL & processing update userinfo set pageurl = 'myjsp? Page = 1 & pagesize = 10 'where id = 'test' www.2cto.com? Two methods: 1) update userinfo set pageurl = 'myjsp? Page = 1' | '&' | 'pagesize = 10' where id = 'test' 2)

Generally, it is only used as a client to access Oracle and does not need to install a large Oracle database. Sometimes I often forget how to configure the lite version of Oracle. This article creates a record backup. You can download the client

Query all values in a comma-separated string in oracle. If a string is separated by a comma or another symbol, you want to split it into columns, such as 'first field, second field, third field ', www.2cto.com is split into first field second field

Common oracle commands tnsping Oracle Net tool (command) tnsping is an OSI Session Layer tool used to: 1) Verify name resolution (name resolution, of course, it is oracle's own network service name) 2) whether the remote listener starts www.2cto.com

PL/SQL programming method Daquan I. dynamic SQL splicing (using replace) www.2cto.com pay attention to using replace to achieve dynamic SQL splicing effect, v_psql can be used to pass variables [plain] 1 declare 2 a number: = 2; 3 v_ SQL varchar2 (40