Oracle

Take Oracle Database for example 1 use of exists exists is used only for subqueries, can be substituted in, and if matched to result, exit internal query, and returns the entire result data with the condition flag to true, in whether or not the

SELECT t.*From Tablekind TWHERE (T.column1, T.column2) in(' 1101 ', ' 1100100 '), (' 1102 ', ' 1102700 '), (' 1104 ', ' 1105200 '),(' 1105 ', ' 1105400 '), (' 1109 ', ' 1109000 '), (' 1207 ', ' 1207001 '),(' 2101 ', ' 2107100 '), (' 2102 ', ' 2107200

Two simple row and column transpose1, the row and column conversion of fixed numberSuch asStudent Subject Grade--------- ---------- --------Student1 Language 80Student1 Math 70Student1 English 60Student2 Language 90Student2 Math 80Student2 English 10

1 View database locks, diagnose the source and type of locks Select Object_id,session_id,locked_mode from V$locked_object;or use the following command:Select B.owner,b.object_name,l.session_id,l.locked_modeFrom V$locked_object L, dba_objects bwhere

You're still struggling to figure out how to quickly count the total number of records in a table with lots of data. Are you still using SELECT COUNT (*) from table_name? I can try my new discovery: Direct COUNT (*) is time-consuming when you

The query process for a SELECT statement by an Oracle database is shown in the following illustration: As we know from the above picture, There are three main steps: The client sends a SELECT statement to the server, the server executes the SQL

Oracle Analyze Table2008-09-23 13:25 Url:http://hi.baidu.com/jdsnhan/blog/item/36fe7e01790809087bec2c31.html Let's take a brief note. Today, helping colleagues guide the data, from the development environment to the test environment, found that a

Oracle Start listening Service Lsnrctl start Stop the Listening service Lsnrctl stop Ora-12514:tns: The listener is currently unable to recognize the service requested in the connection descriptor Need to configure Listener.ora files in Oracle

1, check your server Oracle monitor is started: lsnrctl status If you do not create a listener or do not start, the remote is inaccessible. 2, check your client can connect to the server 1521 ports: telnet Server IP 1521 because it is

ORACLE Login Error (ora-01033:oracle initialization or shutdown in progress It says the example of creating a table partition, so create a table space when the creation of several table space physical files, then feel the creation of the wrong, want

The following method requires oracle9i and more versions to support it. Before Oracle9i, Chinese is sorted according to binary encoding. In oracle9i, according to pinyin, radical, stroke sorting function. Set Nls_sort value Schinese_radical_m sorted

Parallel DDL Sql> CREATE index idx_t3 on T1 (object_name,object_id) parallel;The index has been created.Sql> Select Index_name, degree from user_indexes where index_name= ' idx_t3 ';No rows selectedSql> Select Index_name, degree from user_indexes

has been entangled in the stored procedure is and as recently on the Internet to check the huge amount of information, summed up as follows: There is no difference in stored procedures (PROCEDURE) and functions (function); Only as cannot be used in

The project needs to create temporary tables to temporarily store a table of data that we know can be implemented with subqueries, and the syntax is simple: Create global temporary table Temp1 as select * from Jjr_tjjr_cyzgxx By querying the

1. Add Column ALTER TABLE table_name ADD (column datatype [DEFAULT expr][,column datatype ...]); For example: Sql>alter TABLE emp01 ADD Eno number (4); 2. Modify the column definition For example: Sql>alter TABLE emp01 MODIFY Job VARCHAR2 (15)

Method One: You can configure it by opening the Tnsnames.ora in the Oracle installation directory as follows: Specific path such as: F:\app\Administrator\product\11.2.0\dbhome_1\NETWORK\ADMIN\tnsnames.ora # Tnsnames.ora Network Configuration File:f:\

If you want to implement a data table primary key increase in the Oracle database, there seems to be no way to define the properties of a column directly like MySQL. However, we still have a way to implement the common functions of this database.

Sometimes accidentally switch to the Virbox view of the switch to Scaled Mode,vbox above the control bar disappeared, when in order to facilitate switching to other view mode, there is nothing to find the control button. Then you need to switch the

ORACLE Date _:Submitdate=datetime.parse (submitdate). ToString ("D-m month-yyyy"); Current time: Sysdate ()To_date (' 2002-01-02 ', ' yyyy-m-dd ') select COUNT (1) from l_perm where CANCEL <> ' Y ' and (sysdate-perm_date) >3 Debugging and

1. Add columns ALTER TABLE table_name Add (column datatype [DEFAULT expr][,column datatype ...]); For example: sql>alter TABLE emp01 ADD Eno number (4); 2. Modify the column definition for example: sql>alter TABLE emp01 MODIFY job VARCHAR2 2