Oracle

Formatting the current time in Oracle and Mysql: public String queryOracleTime () {SQLQuery query = null; String resultSql = "select to_char (sysdate, 'yyyymmddhh24miss ') from dual "; query = (SQLQuery) getSession (). createSQLQuery (resultSql);

Step 1: view the table space usage in Oracle: SQL code www.2cto.com select dbf. tablespace_name, dbf. totalspace "Total (M)", dbf. total totalblocks as blocks, dfs. freespace "total remaining amount (M)", dfs. freeblocks "remaining blocks", (dfs.

PLSQL creates users and assigns permissions 1. First, use the dba permission role to log on to PLSQL 2. Select File-New-User and enter the account and password to be created, select the tablespace www.2cto.com 3. You must assign the following

There are only two basic ways to access oracle Data: Full scan or index scan. The default index type is B-tree index. The index is created on one or more columns or column expressions in the table, and the column value and row number (ROWID) are

One-to-multiple table Field update SQL statement table T_A www.2cto.com id name1 Zhang weisan 2 LITH table T_ B id name1 zhangs1 zsan1 zs2 lisi2 ls www.2cto.com objective: change the name of the record corresponding to the id in Table T_ B and the

Oracle lpad usage pad Translation: Fill the lpad function, add the specified String on the left side of the String, usage: www.2cto.com lpad (String, capture length, added String ). It is not accurate to add a String. A more accurate statement is to

When ORACLE fails to delete the current connected user and solves the problem of deleting the user in Oracle, the following message is displayed: ORACLE cannot delete the current connected user www.2cto.com. You can use the following statement to

Delete an oracle database in a linux operating system. turn off the oracle server and background processesps-ef | grep ora www.2cto.com turn off the database shutdown immediate2. turn off the listener lsnrctl status and execute lsnrctl stop if it is

Oracle notes: Tables and fields (1) 1. CREATE a TABLE: www.2cto.com first CREATE a TABLE and a field: create table mytable (id number (12) not null, NAME VARCHAR2 (32), DESP VARCHAR2 (100), age number (3 ), brithday date default sysdate) tablespace

Oracle queries table space usage SQL code select f. tablespace_name,. total, u. used, f. free, round (u. used/. total) * 100) "% used", www.2cto.com round (f. free/. total) * 100) "% Free" from (select tablespace_name, sum (bytes/(1024*1024) total

Oracle 11g the account is locked. Www.2cto.com 1. Failed to log on multiple times (the password may be incorrect); 2. the user is locked manually by the Administrator; 3. The user password expires, the password is not modified on time, and so on.

Oracle resets sequence Statement 1 SQL code www.2cto.com DECLARE n NUMBER (10); tsql VARCHAR2 (100); p_seqName varchar2 (20); BEGIN p_seqName: = 'seq _ RUN_ID '; execute immediate 'select' | p_seqName | '. nextval from dual 'into n; n: =-(n-1); tsql:

Using plsql Developer to change the primary key when you change the primary key through plsql Developer (plsql is a procedural language), if you only change the primary key, an error will be reported when you click Save, because you have not changed

In Oracle sorting, the first data entry needs to update the large unit of the set group. The rule is to obtain the unit information of the first student (minimum set ID. Sort by SUITEID to obtain the first method. Www.2cto.com SQL code UPDATE

In Oracle, RAISE exception details are thrown in three ways: www.2cto.com 1. use the PL/SQL Runtime Engine 2. use RAISE Statement 3. call the RAISE_APPLICATION_ERROR stored procedure. When an error occurs during database or PL/SQL running, an

Oracle temporary table application problems some people have provided the best optimization ideas on the Internet: 1. first, extract the records that meet the conditions in the large table to generate a temporary table. 2. then, associate the small

Oracle tools: analyze (I) three major functions www.2cto.com ① collect and delete indexes, statistical information of tables and clusters ② verify the structure of tables, indexes and clusters ③ identification tables and cluster and row migration

Using BCV to back up Oracle Database BCV (Business continuous Volume) is short for Business continuity Volume and the concept of EMC's product TimeFinder. It can be used for backup of massive databases and creation of Test Databases. One of the

Oracle sqlnet. ora configures sqlnet. the role of ora (As pointed out on the official website) www.2cto.com 1. restrict client access (for example, if the specified client domain is not allowed) 2. specify the naming method (local naming, directory

Oracle-commonly used monitoring SQL statement 1. monitoring instance waiting: select event, sum (decode (wait_time, 1) prev, sum (decode (wait_time, 0) curr, count (*) from v $ session_wait group by event order by 4; 2. contention for rollback