Here is a list of the comparison operators that you can use in Oracle/PLSQL: Comparison OperatorDescription = Equal <> Not Equal != Not Equal > Greater Than >= Greater Than or Equal < Less Than <= Less Than or
我们可以用PL/SQL灵活安全地操作Oracle数据,因为它支持所有的SQL数据操作语句(除了EXPLAIN PLAN),事务控制语句,函数,伪列和操作符。PL/SQL还支持动态SQL,能让我们动态地执行SQL数据定义,数据控制和会话控制语句。除此之 外,PL/SQL还遵循ANSI/ISO的SQL标准。 1、数据操作 我们可以使用INSERT、UPDATE、DELETE、SELECT和...
ELSE dbms_output.put_line('X is not less than 10'); END IF; END; / 结果: X is not less than 10 PL/SQL procedure successfully completed C:IF - ELSIF - ELSE 语句 基本语法: 复制内容到剪贴板 程序代码 IFTHEN ELSIFTHEN ELSIFTHEN ELSE END IF; Example: 复制内容到剪贴板 程序代码 set se...
You would receive the following error message: You could correct this error by adding the missing equal sign, as follows: SELECT * FROM suppliers WHERE supplier_id != 1000; This statement would return all suppliers whose supplier_id is not equal to 1000....
ORACLE性能优化之SQL语句优化 操作环境:AIX +11g+PLSQL 包含以下内容: 1. SQL语句执行过程 2. 优化器及执行计划 3. 合理应用Hints 4. 索引及应用实例 5. 其他优化技术及应用 1.SQL语句执行过程 1.1 SQL语句的执行步骤 1)语法分析,分析语句的语法是否符合规范,衡量语句中各表达式的意义。
*ORACLE10g以后的版本,SQL优化的本质是基于对CBO和执行计划的深刻理解,进入CBO时代,一定要理解执行计划。 *查看执行计划有好多方式,比如使用PL/SQL Developer工具,选中select语句,按F5键就可以显示其执行计划,不过显示的不完全 *最好使用在Oracle官方的sqlplus工具,性能最好,方便直观,下面介绍两种查看执行计划方式(也是...
From a PL/SQL block or subprogram, you use dot notation to reference a packaged cursor, as the following example shows: DECLAREemp_rec emp%ROWTYPE;...BEGIN...OPEN emp_stuff.c1;LOOPFETCH emp_stuff.c1 INTO emp_rec;EXIT WHEN emp_suff.c1%NOTFOUND;...END LOOP;CLOSE emp_stuff.c1;END; ...
所有的PL/SQL块都是以“END;”结束 2015-6-21 PL/SQL基础 •3.定义部分 •⑴定义常量或变量 •标识符[constant]数据类型[notnull] •[:=默认值或PL/SQL表达式]注: 如果加上关键字constant,则表示所定义的是一个常量,必须为它赋初 值,在程序中只能引用而不能再改变其值。 每行只能定义一个标识符...
plsql_native_library_subdir_countparameter Some file systems may not be capable of handling large number of files in a single directory; you may need to create sub directories under the directory specified byplsql_native_library_dirfor storing the native compilation generated shared libraries. ...
Some export type can not or should not be load directly into the PostgreSQL database and still require little manual editing. This is the case for GRANT, TABLESPACE, TRIGGER, FUNCTION, PROCEDURE, TYPE, QUERY and PACKAGE export types especially if you have PLSQL code or Oracle specific SQL ...