例如在窗口sql*plus 1 中修改emp 的数据 updateempsetsal=sal+100whereeno='123'; 虽然sql*plus 1 窗口已经提示更新, 但是事务没有提交! 此时再打开另一个窗口sql*plus2 , 同样也执行修改, 执行上述同样的语句, 不是提示已更新, 而是一直等待. 这是因为sql*plus 1 封锁了记录, 但是事务没有结束, 锁不会...
PL/SQL Developer设置快捷输入常用SQL字段: 针对一些常用的SQL字段,比如:select, insert into, update, delete等等,我们经常大量用到,每次都手动一个字母一个字母的输入就显得很麻烦也不炫酷,所以我们就可以设置一下快捷输入。 比如:输入s之后按下空格,自动输入select;或者输入sf按下空格就自动变为select * from,这...
sql_str :=sql_str||'if updating then'; (4)拼接,判断字段是否有变更,如若有记录下来 --get every column_name by table_nameforcolumns_namein(selectt.table_name,t.column_namefromuser_tab_columns twheret.TABLE_NAME=tables_name.table_name ) loop--the second set column to sql_strsql_str :...
PL/SQL – Complex Queries (Job Interviews) (srinimf.com) PL/SQL – Difficult Questions (srinimf.com) Share this: Tweet Share WhatsApp More Srini Data Engineer with deep AI and Generative AI expertise, crafting high-performance data pipelines in PySpark, Databricks, and SQL. Skilled in Python...
Write a code in PL/SQL to design a trigger that captures changes made to specific columns and logs them in an audit table. Sample Solution: PL/SQL Code: -- Create the employees tableCREATETABLEemployees(employee_id NUMBERPRIMARYKEY,employee_nameVARCHAR2(100),salary NUMBER);-- Create the sal...
PL/SQL Triggers - Learn about PL/SQL triggers, their types, and how to use them effectively in your database applications.
The syntax to create aBEFORE UPDATE Triggerin Oracle/PLSQL is: CREATE [ OR REPLACE ] TRIGGERtrigger_nameBEFORE UPDATE ONtable_name[ FOR EACH ROW ] DECLARE -- variable declarations BEGIN -- trigger code EXCEPTION WHEN ... -- exception handling END; ...
This Oracle tutorial explains how to create an AFTER INSERT Trigger in Oracle with syntax and examples.Description An AFTER INSERT Trigger means that Oracle will fire this trigger after the INSERT operation is executed.Syntax The syntax to create an AFTER INSERT Trigger in Oracle/PLSQL is: ...
触发器也是一种带名的PL/SQL块。触发器类似于过程和函数,因为它们都是拥有声明、执行和异常处理过程的带名PL/SQL块。与包类似,触发器必须存储在数据库中并且不能被块进行本地化声明。 对于触发器而言,当触发事件发生的时候就会显式地执行该触发器,并且触发器不接受参数。
trigger_body:触发体,是标准的PL/SQL语句块 (2)替代触发器(instead of触发器) 对视图进行操作时定义的触发器,替代触发器只能定义在视图上 代码语言:javascript 代码运行次数:0 运行 AI代码解释 语法: create[or replace]trigger trigger_name--触发器名称 ...