Oracle

Writing a function first is a way to MD5Create FUNCTION invarchar2)RETURNvarchar2isBEGIN RETURN = Upper (P_STR))); END;And then call inside the stored procedureCreate procedure as begin Update Set User_pwd=get_md5 ('123456'); End

Transaction: A separate logical unit of work. It has a specific series of SQL statements that must be successful or failed as a whole. is an all-or-nothing, very personality of the East.Four properties of a transaction--acid properties: Atomicity

Using the table under the Scott user,1. Query All contentSELECT * from EMP;2. Query employee information, including employee number, name, position 3 informationSELECT empno,ename,job from EMP;3. Find All JobsSELECT JOB from EMP;4. Check all

Oracle creates self-growth write sequences and write triggers, not as convenient as MSSQLSERVER. But it is also a hassle, recorded as follows:In Oracle, you can create a separate sequence for the primary key of each table, and then get an

First, the function1, take the whole mod (2,10) =22, take the whole trunc (12/10) =13, take the whole ceil (12/10) =24, NULL (NULL) specifies a value NVL (null,9) =95 cumulative sum (piece) =883476. Count of Statistics (keyID) =194Second, arithmetic

Slow query speed due to a large number of delete operations causing the space to not be released and the horizontal bit high--high level position due to a large number of delete operations causing the space to not be releasedALTER TABLE

[Email protected] ~]$ export ORACLE_SID=ORCL[Email protected] ~]$ Sqlplus/as SYSDBASql*plus:release 10.2.0.1.0-production on Mon Nov 10 23:04:36 2014Copyright (c) 1982, 2005, Oracle. All rights reserved.Connected to an idle instance.sql> startup

One, shutdown command:Shutdown has four parameters: NORMAL, transactional, IMMEDIATE, ABORT. The default is normal if no parameters are taken.SHUTDOWN NORMAL: Do not allow new connections, wait for the session to end, wait for the transaction to end,

Any action on a column can result in a full table scan, where the so-called operations include database functions, calculation expressions, and so on, to move the operation to the right of the equation whenever possible.Even remove the

Previously written, and later did not write, since all forgotten. Here re-learning Oracle's stored procedures, want to see people do not laughed at.It is first known that the start statement of the stored procedure is create OR REPLACE PROCEDURE

syntax structure: INSERT into table name (column name 1, column Name 2 ...) Values (value 1, value 2 ...)Code Demo:Sql> INSERT into Infos VALUES (①2 ' s100102 ', ' lin ', ' Male ', 22, 2,3 to_date (' 2009-8-9 06:30:10 ', ' yyyy-mm-dd HH24:MI:SS '),

---is executing theSelect A.username, A.sid,b.sql_text, B.sql_fulltextFrom V$session A, V$sqlarea bwhere a.sql_address = b.address ---executed.Select B.sql_text,b.first_load_time,b.sql_fulltextFrom V$sqlarea bwhere b.first_load_time between ' 2009-10

Oralce time conversion usage TO_CHAR (DATE, FORMAT) 1. This week, this month, and this year -- This week select trunc (sysdate, 'D') + 1 from dual; -- Monday select trunc (sysdate, 'D') + 7 from dual; -- Sunday -- select trunc (sysdate, 'mm') from

Oracle performance optimization operation 1: Avoid Column Operations Any operation on a column may cause a full table scan. Here, the so-called operations include database functions, calculation expressions, and so on. During query, try to move the

What is Scalability ?, Whatisscalability Scalability is a system's ability to process more workload, with a proportional increase in system resource usage. in other words, in a scalable system, if you double the workload, then the system uses twice

Oracle user password Modification How to change the user password in Oracle In the Oracle database, use alter user to change the user password. Syntax Alter user user_name identified by new_password; Parameter description: User_name: the

Considerations for oracle Transaction Processing (notes) and oracle Transaction Processing Transaction: An Independent logical unit of work. It has a specific series of SQL statements that must be successful or failed as a whole. It is a kind of

How can I use the IP address modified by ORACLE? After the IP address of the oracle database server changes, the listening process cannot be started. You need to modify the corresponding configuration file: 1. Modify the address host on the server

Oracle index creation You can use indexes appropriately to increase the data retrieval speed and create indexes for fields that frequently need to be queried. Oracle indexes are divided into five types: Unique indexes, composite indexes, reverse

Oracle Data insertion Syntax structure: insert into Table Name (column name 1, column name 2 ......) VALUES (value 1, value 2 ......) Code Demonstration: SQL> INSERT INTO INFOS VALUES (①2 's10010', 'lin chong', 'male', 22, 2,3 TO_DATE ('2017-8-9 0