1 DECLARE 2 No NUMBER; 3 Name VARCHAR2(20); 4 BEGIN 5 DBMS_UTILITY.EXEC_DDL_STATEMENT(' 6 CREATE OR REPLACE VIEW myview AS 7 SELECT empno, ename, ''E'' type FROM emp 8 UNION 9 SELECT dept.deptno, dname, ''D'' FROM dept 10 '); 11 -- 创建INSTEAD OF 触发器trigger3; 12 DB...
Oracle Database PL/SQL Language Referencefor more information aboutCASEexpressions "Using the DECODE Function in Queries" "Using the CASE Statement" Using the DECODE Function in Queries TheDECODEfunction compares an expression to several search values. Whenever the value of the expression matches a se...
1.win + R打开dos窗口 2.输入:"sqlplus scott/tiger" 连接数据库 "show user":显示当前用户 conn 账户/口令:连接别的用户 select username,account_status from dba_users:查看用户状态 还可以指定用户名:select username,account_status from dba_users where username = 'SCOTT'; 删除用户时,若级联删除不允许...
通常一个连接(connect)在客户端进程和服务进程或调度进程(dispatcher)之间产生,也有可能在客户端进程和CMAN(oracle 进程管理器)之间产生。一个连接可能会有0,1,或者多个会话,本题是SCOTT用户使用SQLPLUS连接数据库后,发起了一个会话。属于客户端和服务端进程连接。故选BA错:没有用户进程这个说法C:SMON -负责各种...
The "disk" column is the one we're interested in. In this case, the SQL statement above this summary has fetched 34 database blocks from disk. The next column, query, is the number of block fetches, but most of these will have been from cache. ...
总结起来,Oracle SQLPlus是Oracle数据库的命令行工具,替代变量是SQLPlus中的一种特殊变量,用于在SQL语句中动态替换为实际的值。两次使用替代变量是指在SQL*Plus中多次使用相同的替代变量,它可以提高执行相同SQL语句的效率。 、 如何输入替代变量,使其可以在整个SQL语句中多次使用?例如FROM T; 将每个X视为不同的变量。
|2|BITMAPCONVERSIONCOUNT||86565|5(0)|00:00:01||3|BITMAPINDEXFASTFULLSCAN|IDX_BITM_T_STATUS|||---Note---dynamic sampling usedforthisstatement(level=2)
Runs an XQuery 1.0 statement. Supported SET commands SET APPI[NFO]{ON | OFF | text} Sets automatic registering of scripts through the DBMS_APPLICATION_INFO package. SET AUTO[COMMIT]{ON | OFF | IMM[EDIATE] | n} Controls when Oracle Database commits pending changes to the database. ...
is select_statement -- 定义游标对应的select语句,可用上所有cursor定义的参数和存储过程的in类型参数。 [for update -- 定义for update后,则可在循环游标时,通过where current of cursor_name来更新或删除当前游标所在行数据,会默认给select语句中所有表加共享锁。
The new 2nd edition of our Oracle SQL*Plus Pocket Reference includes many new features for Oracle9i (e.g., COALESCE function, searched CASE expressions, new table join syntax, partition operations, MERGE statement, and syntax changes in existing SQL*Plus statements such as ACCEPT, DESRIBE, HELP...