This Oracle WHERE clause example uses the WHERE clause to define multiple conditions. In this case, this SELECT statement uses the AND condition to return all suppliers that are located in the state of California and whose supplier_id is less than or equal to 750.Example...
If no values in WHERE clauses match the result of the selector in the CASE clause, the sequence of statements in the ELSE clause executes. Because the ELSE clause is optional, you can skip it. However, if you do so, PL/SQL will implicitly use the following: ELSE RAISE CASE_NOT_FOUND...
CASE [ TRUE | [selector_variable]] WHEN [criterion1 | expression1] THEN criterion1_statements; WHEN [criterion2 | expression2] THEN criterion2_statements; WHEN [criterion(n+1) | expression(n+1)] THEN criterion(n+1)_statements; ELSE block_statements; END CASE; 3.迭代语句 23:24:02 SCOT...
PL/SQL is case sensitive within character literals. For example, PL/SQL considers the literals'Z'and'z'to be different. Also, the character literals'0'..'9'are not equivalent to integer literals but can be used in arithmetic expressions because they are implicitly convertible to integers. Str...
第六章 PL/SQL与Oracle间交互 一、PL/SQL支持的SQL一览 PL/SQL扩展了SQL,变得更加强大和易用。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
2.1.4 SQL语句结构SQL语言由一些简单句子构成基本的语法,所有的SQL语句均有自己的格式,典型的SQL语句(查询语句)结构如图2.1所示。图2.1 典型的SQL语句结构SQL语法的基础是子句(clause),子句中会包括一些关键词(keyword)。每条SQL语句均由一个关键词开始,该关键词描述这条语句要产生的动作。SQL中常用的关键词及其功能...
一、PL/SQL基础知识 1、PL/SQL简介 PL/SQL概述 PL/SQL(Procedural Language)是Oracle在关系数据库结构化查询语言SQL基础上扩展得到的一种过程化查询语言。 SQL与PL/SQL SQL与编程语言之间的不同在于,SQL没有变量,没有流程控制(分支、循环)。而PL/SQL是结构化和过程化的结合体,而且最为重要的是,在用户执行多条...
A string literal might have been mistakenly enclosed in double quotes instead of single quotes, in which case PL/SQL considers it a quoted identifier. Action: Shorten the identifier. PLS-00115 this PRAGMA must follow the declaration of 'string' Cause: The pragma refers to a PL/SQL object ...
PL/SQL Beautifier Options PL/SQL美化器选项Cut 剪切 Copy 复制 Paste 粘贴 Append 附加 Clear 清除 Select All 全选 Recall Statement 重新调用语句Special Copy 专用复制 Selection 选择 Indent 缩进 Unindent 撤销缩进 Uppercase 大写 Lowercase 小写 Comment 注释 Uncomment 取消注释 Apply Syntax Case 英语语法大小...
考虑下面的SQL语句: -- 建表 create table t1(id int); -- 插入 insert into t1 values(1),(2),(3); -- 查询 select * from t1 where id = 1; 1. 2. 3. 4. 5. 6. 对于select语句,由于我们并没有为t1表创建索引,所以只能通过全表遍历的方式来执行查询。全表遍历会遍历表的所有块,逐条获取...