Oracle

Directory structureInit script|----orcl_sql|----init_user.sql|----tab_home.sql |----Tab_user.sql |----init.batInit.bat@echo Off@echo---------------------------------------------------------------------@echo ^| ^| @echo ^|

Transaction:A transaction is a set of related actions performed as a single logical unit of work.These operations require all or none of them to be completed.Reasons for using transactions: Ensure data is safe and effective.Four characteristics of a

1 CREATE OR REPLACE TriggerTrig_solr_index_el_lesson2AfterUpdate ofLessonid, Lessonname, lessongoal, note, TeacherName, Teacherid, Classidname, ClassID, Crtime, statusOr Delete or Insert onEl_lesson3 forEach Row4 Declare5 --Local Variables

Note the point:1: A sequence can be shared by multiple tables.2: The number sequence generated by sequence shared by multiple tables is always continuous and does not start again.3: If the sequence is no longer used, delete it.SELECT * from DAYSBFJ.

SELECT a.table_name table name,c.comments Table notes,A.column_name Field Name,REPLACE (DECODE (A.data_type,' DATE ',' DATE ',' VARCHAR2 ',' VARCHAR2 (' | | A.data_length | | ‘)‘,' Number ',' Number (' | | a.data_precision | | ', ' | | A.data_scale |

1. PL/SQL Interpretation Plan windowAdvantages: AspectsCons: See limited information2. Explain_plan forEasier to optimize for a sentence3, SqlplusEnter the command in Sqlplus:Set Autotrace onSELECT * from EMP;After the data is displayed, follow the

Original Address--http://blog.csdn.net/qq525099302/article/details/47253641SELECT * FROM b_role_authority as of timestamp to_timestamp(‘2015-07-25‘,‘yyyy-mm-dd‘)Note: The table structure changes after the invalid, can only query for a period of time

Oracle's SQL statement optimizationOptimization of SQL statements1. The Oracle optimizer cannot use indexes when using is NULL or is not NULL in the WHERE clause.2. For connected columns, even if the most one is a static value, the optimizer does

INSTR Usage:INSTR (string,substring,position,ocurrence)Explanation: string: source stringSubString: substring to findPosition: The start position of the lookup. If the starting position is 0, the return value is 0, and when the starting position is

For the sake of convenience, the following simple models are established and some test data are constructed:In a business admissibility subsystem BSS,SQL Code --customer data sheet Create table customers ( customer_id

1 administrator identity into the CMD environment, execute the DBCA command, in the boot of the popup window, complete the instance creation2 if the appropriate character set is not selected during the creation process (preferably with the default

In many cases, a database is just a few blocks of data file corruption. In this case, of course, we use database recovery or data file recovery to solve the problem. But the feeling of a little flak hitting the mosquitoes. Fortunately, Rman provides

Disclaimer: This article is for bloggers in the project to use some of the common commands, do not reprint.Oracle Common Naming SummaryTo create a table space:--create tablespace VMS--datafile ' e:\vms.dbf '--size 32000M--extent Management local

Bitand () function in Oraclereturns the result of two numeric numeric values after a bitwise AND operation.GrammarBitand (NExpression1, NExpression2)ParametersNExpression1, NExpression2Specifies the two numeric values for the bitwise AND operation.

Oracle hierarchical query and Oracle hierarchical Query The syntax for Oracle hierarchical query is as follows: The following are based on two questions: 1. according to the chronological order, the English names of the twelve constellations are

Oracle Display object space usage show_space Tom wrote a script to view the object space usage of the Oracle database.The following shows how to use it: -Tool source code CREATE OR REPLACE PROCEDURE show_space(p_segname IN VARCHAR2,

Oraclebetweenand Boundary Problems -- Create a table create table test_hsj (id int primary key, num varchar2 (12), regDate date) select * from test_hsj; -- insert test data insert into test_hsj values (1, '1', to_date ('2017-05-01 ', 'yyyy-MM-dd')

Accessing other Oracle database data from Oracle Data Create a database link in the local oracle databaseDrop database link mydblink;Create database link mydblink connect to zszq identified by "zszq" using '192. 168.0.175: 192/orcl '; SQL> DROP

In oracle, how does one obtain the local IP address and the domain name based on the IP address?----- Resolve the ip addressSQL> select utl_inaddr.get_host_address ('Google. com') from dual;UTL_INADDR.GET_HOST_ADDRESS ('Google. com ')----------------

Oracle11gexp export problem: some tables cannot be exported An issue found during command exp export from oracle is that some tables cannot be completely exported. After checking, it is found that any blank table cannot be exported. In the