Oracle

1, first set up a directory : Create directory directory name as ' a directory on the database server ', such as: Create directory alias as ' d:\ server directory name '; Put the imported or exported files in this directory 2, Export and

An error was encountered while installing Oracle Preparing to launch Oracle Universal Installer from/tmp/orainstall2011-11-03_12-53-01pm. Please wait ... [Oracle@localhost database]$ Exception in thread ' main '

to see if an Oracle database is in archive mode Sql> select Name,log_mode from V$database; NAME Log_mode ------------------ ------------------------ TEST Noarchivelog Sql> Archive Log List Database log mode No Archive mode Automatic Archival

What happens when we define a field name and alias with the same name as the Oracle keyword? It's really simple, just add "" to this keyword, such as "group" Look at the following example: Copy Code code as follows: sql> DROP TABLE

The following error is always reported today when manually configuring ORACLE11G's EM: Warning:ora-00001:uniqueconstraint (Sysman. Parameters_primary_key) violated Ora-06512:at "Sysman. Emd_loader ", line4986 Ora-06512:atline1 There is no solution

Oracle has many locks, and the utility of various locks is not the same. Oracle row-level locks are highlighted below, and Oracle row-level locks lock only the rows that the user is accessing. Can better guarantee the security of the data. If the

The DISTINCT keyword can only filter all records in the query field (same Recordset), and if you want to specify a field without effect, another distinct keyword is sorted and inefficient. The select distinct name from T1 can eliminate duplicate

Row_number () over (partition by col1 ORDER by col2) is grouped according to col1, sorted by col2 within the group, and the value of this function represents the sequential number of the internal sort in each group (a sequential unique within the

1: Create user Copy Code code as follows: Create temporary tablespace user_temp Tempfile ' D:\app\topwqp\oradata\orcl\user_temp.dbf ' Size 500m Autoextend on Next 50m maxsize 2048m Extent management Local; Create

1, UPDATE nowait Apply the following scenario: Query a data and open database transactions to it. If the current data for the query is not locked, the result is returned correctly and the current data is locked, if the current data for the query is

In Oracle, the Utl_file package provides functions and procedures for manipulating text files, and learns about his basic operations 1. Create directory and authorize users Copy Code code as follows: --Create Directory Create or

/* 1th step: Create temporary table space/*Create temporary tablespace user_tempTempfile ' D:\oracle\oradata\Oracle9i\user_temp.dbf 'Size 50mAutoextend onNext 50m maxsize 20480mExtent management Local; /* 2nd step: Create a datasheet space/*Create

The total number of fields queried for a table in Oracle, using SQL statements, or in Pl/sql Copy Code code as follows: Select COUNT (column_name) from user_tab_columns where table_name= ' T_b_auditor ' The number of fields

1, view the currently unlocked object Example: A table AA lock is executed with a select * from AA for update; Way one: Through SQL query Select ' Alter system kill session ', ' ' | | Trim (t2.sid) | | | Trim (t2.serial#) | | From V$locked_object t1

1, the character type turns into timestamp Copy Code code as follows: Select To_timestamp (' January-October-08 07.46.41.000000000 a.m. ', ' Dd-mon-yy hh:mi:ss.ff am ') from dual; 2, timestamp turn to date type Copy

SQL statements for querying and deleting duplicate records1, look for redundant records in the table, duplicate records are based on a single field (ID) to judgeSELECT * FROM table where ID in (select Id from table GROUP by ID have count (Id) > 1)

Oracle database View How a process is executing the relevant actual SQL statements Copy Code code as follows: SELECT b.sql_text, sid, Serial#, Osuser, machine From V$session A, V$sqlarea b WHERE a.sql_address = b.address;

The following SQL statements can be used in Pl/sql to query which tables in the current database are locked and which users lock them: SELECTA.owner,--object owned userA.object_name,--object name (table name)B.XIDUSN,B.xidslot,B.XIDSQN,B.SESSION_ID,

Using ORA to enter data into the datasheet ' Email_info ' When the user browses this script, displays a form that consists of a name, an email input field, and when the user adds a good data click Submit, the script will save the name and email to

Create A Table Using OCI Below we will create an email personal information book. This time using the OCI8 API directive Related PHP Code: PUTENV ("Oracle_sid=orasid"); $connection = Ocilogon ("username", "password"); if ($connection = = False)