Oracle

A long time ago touched this problem, today to find out the original written a functionSelect B.remark,Long_to_char (B.rowid, NULL, ' tmp20180518102050381 ', ' remark ')from tmp20180518102050381 B;CREATE OR REPLACE FUNCTION Long_to_char (in_rowid

#!/bin/bash./etc/Profile .~/. Bash_profileoracle_base="/opt/oracle11g"Export Oracle_baseoracle_home="/opt/oracle11g/product/11.2.0"Export Oracle_homeoracle_sid="ORCL"Export Oracle_sidexport Nls_lang=American_america. Zhs16gbkld_library_path="$ORACLE

Merge into form:MERGE into [target-table]A USING[source-table SQL]B on([conditional Expression] and [...]...) whenMatched Then [UPDATE SQL] when notMatched Then [INSERT SQL] Function: To determine whether B and a table meet on the

When two SQL literals are the same, and other environments are different, the two cursors cannot share the execution plan. They all have their own execution plans in the cache library. These two cursors are child cursors, and Oracle also creates a

When multiple people operate the same table in the Oracle database at the same time, it often causes the lock table phenomenon, which needs to be unlocked manually.First of all: First look at those tables are locked, the program is as

Reason one Oracle generates ROWMUN,ROWID fields for each table by default, and these fields we call pseudo-columns1 Creating a Test tableCREATE TABLE TEST (ID number,name VARCHAR2 (20))2 Inserting test dataINSERT into test values (1, ' Zhang San ');

1. Course Objectives① Mastering the basic syntax of SQL queries②sql the various operations for querying2. Specific contentIf you want to make a SQL query, then we need to use the knowledge of select in Dql, and for simple queries, the popular

This clause is mainly used for the data recursive query of the B-tree structure type, giving any node in the B-tree structure type, traversing its final parent node or sub-node.First look at the original data:1 CREATE TABLE A_test 2 (ParentID

Background When operating Oracle, when multiple people operate the same table in the Oracle database at the same time, it often results in a lock table phenomenon that needs to be unlocked manually. Steps Log in to the Oracle database

With as corresponds to a virtual view.Example: Requirement Description The total value of the Y column is counted according to the X column, and the ultimate goal is to select One-third of the total value of the Y column for those grouping

1, classnofoundexception can not find the registration driverPossible cause:1> driver name is incorrect2> Database driver package not imported2, the SQL statement can use any valid function, function operation of the column, you must specify an

Oracle view encoding and modify encodingFirst look at the encoding of the Oracle databaseSql> SELECT * from nls_database_parameters where parameter = ' nls_characterset

Demand:1 According to the information in the Customer information table to compare the corresponding balance.The 2 table has the customer number, the balance, the partition information at each point in time, and the unique customer number in each

Insert into TabName (datecol) value (sysdate); --With a date valueInsert into TabName (datecol) value (sysdate+1); --With a date valueInsert into TabName (datecol) value (to_date (' 2014-02-14 ', ' yyyy-mm-dd ')); --With To_dateInsert into

Original address: Oracle creates table spaces, creates users, and authorizes ChinacoolswordAfter Oracle is installed, there is a default database in which we can create our own database, in addition to the default database.For beginners, to avoid

Phenomenon:In an Oracle database, it is very slow to use lsnrctl to turn on, turn off listening, or to view the listening state, so that the action can be done immediately by means of a broken network.When a client connects to a database using Plsql

1. It is often necessary to back up database tables in the work, sometimes Baidu or ask, simple.If the backup table does not exist:Oracle Syntax CREATE TABLE ZHAOBSH as SELECT *from zwkmye2017 SQL Server Syntax SELECT * to ZHAOBSH from ZWKMYE20

1. Create a user and set a password Create user username identified by password;  2. Modify User Password alter username identified by password;  3. Delete a user Drop user username  4. Granting user Privilegesgive the user all permissions: grant

1.1.Training Descriptionuse cursors to print information about all employees in the EMP departmentAction Steps AnswerDeclareCursor C_emp is a SELECT * from EMP where deptno=10;V_row Emp%rowtype;BeginOpen c_emp;LoopFetch c_emp into V_row;Exit when

Oracle Statistical informationstudy Oracle FoundationBasic statistics related 1. Which optimizer mode requires statistical information collection, All_rowsAt present O3 recommends that regardless of the mode of statistical information collection,