Control Structures of PL/SQL Control structures are probably the most useful (and important) part of PL/pgSQL.With PL/pgSQL's control structures, you can manipulate PostgreSQL data in a very flexible and powerful way. 1.Returning From a Function RETU…
1 PL/pgSQL Under the Hood This part discusses some implementation details that are frequently important for PL/pgSQL users to know. 1.1 Variable Substitution SQL statements and expressions within a PL/pgSQL function can refer to variables and paramet…
Trigger Procedures PL/pgSQL can be used to define trigger procedures on data changes or database events. A trigger procedure is created with the CREATE FUNCTION command, declaring it as a function with no arguments and a return type of trigger (for d…
Cursors Rather than executing a whole query at once, it is possible to set up a cursor that encapsulates the query, and then read the query result a few rows at a time. A more interesting usage is to return a reference to a cursor that a function has…
1.Structure of PL/pgSQL The structure of PL/pgSQL is like below: [ <<label>> ] [ DECLARE declarations ] BEGIN statements END [ label ]; A label is only needed if you want to identify the block for use in an EXIT statement, or to qualify the na…
IF条件 declare cursor s is select version from city_server t; s_ city_server.version%type; begin open s; fetch s into s_; if s_>2 then DBMS_OUTPUT.put_line(s_); end if; close s; end; LOOP循环 declare …
资料1 -- Created on 2014/8/20 declare -- Local variables here i integer; begin i := 12; -- Test statements here DBMS_OUTPUT.put_line(i); end; 资料2 declare cursor s is select * from city_app.city_server; s_ s%rowtype; begin …
接上文 多线程编程学习笔记——async和await(一) 接上文 多线程编程学习笔记——async和await(二) 五. 处理异步操作中的异常 本示例学习如何在异步函数中处理异常,学习如何对多个并行的异步操作使用await时聚合异常. 1.程序示例代码如下. using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks;…
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本系列文章由@二货梦想家张程 所写,转载请注明出处. 本文章链接:http://blog.csdn.net/terence1212/article/details/44264153 作者:ZeeCoder 微博链接:http://weibo.com/zc463717263 我的邮箱:michealfloyd@126.com 欢迎大家发邮件来和我交流编程心得 you are what you read!与大家共勉! --------------------------------------…
