DB2存储过程如何编写和执行

db2执行文件参数:

-t 表示语句使用默认的语句终结符------分号;

-v 表示使用冗长模式,这样 DB2 会显示每一条正在执行命令的信息;

-f 表示其后就是脚本文件;

-z表示其后的信息记录文件用于记录屏幕的输出,方便以后的分析(这是可选的,但我们建议使用该选项)。

当使用了-t选项而没有标明语句终结符,则分号(;)会默认为语句的终结符。有时可能会出现使用另外的终结符的情况,例如用SQL PL 编写的的脚本使用其它的符号而不是默认的分号,因为分号在SQL PL 是用于定义数据库对象过程中的语句结束。

-d --end的简称,最后一个结束符

存储过程:

;作为DB2默认的SQL命令结束符,即你执行的不是一个创建存储过程的语句,而是多条不完整的SQL语句。

语句中最后一个;换成其它符号,如@,然后使用db2 -td@ -vf insert_log_test.sql(txt、sql都可以) 指定@为命令结束符。

一个简单的存储过程:

vi insert_log_test.sql

CREATE OR REPLACE PROCEDURE INSERT_LOG_TEST()

begin

atomic declare i int default 0;

while(i <10000)

do insert into log_test values (i,'中间提交的事务');

set i=i+1;

end while;

end

@

db2inst1@t3-dtpoc-dtpoc-web04 liys\]$ db2 -td@ -vf insert_log_test.sql CREATE OR REPLACE PROCEDURE INSERT_LOG_TEST() begin atomic declare i int default 0; while(i \<10000) do insert into log_test values (i,'中间提交的事务'); set i=i+1; end while; end DB20000I The SQL command completed successfully. 如果我们把最后一个@删的,然后改成;然后执行db2 -tvf会发生什么?DB2会不会把文件看出一个存储过程,而是普通的DDL语句来执行,以;为DDL等sql的分隔符 \[db2inst1@t3-dtpoc-dtpoc-web04 liys\]$ db2 -tvf insert_log_test.sql CREATE OR REPLACE PROCEDURE INSERT_LOG_TEST() begin atomic declare i int default 0 DB21034E The command was processed as an SQL statement because it was not a valid Command Line Processor command. During SQL processing it returned: SQL0104N An unexpected token "END-OF-STATEMENT" was found following "lare i int default 0". Expected tokens may include: "\". LINE NUMBER=3. SQLSTATE=42601 while(i \<10000) do insert into log_test values (i,'中间提交的事务') DB21034E The command was processed as an SQL statement because it was not a valid Command Line Processor command. During SQL processing it returned: SQL0104N An unexpected token "while(i \<10000) do" was found following "BEGIN-OF-STATEMENT". Expected tokens may include: "\". SQLSTATE=42601 set i=i+1 DB21034E The command was processed as an SQL statement because it was not a valid Command Line Processor command. During SQL processing it returned: SQL0206N "I" is not valid in the context where it is used. SQLSTATE=42703 end while DB21034E The command was processed as an SQL statement because it was not a valid Command Line Processor command. During SQL processing it returned: SQL0104N An unexpected token "END-OF-STATEMENT" was found following "end while". Expected tokens may include: "JOIN \". SQLSTATE=42601 end DB21034E The command was processed as an SQL statement because it was not a valid Command Line Processor command. During SQL processing it returned: SQL0104N An unexpected token "END-OF-STATEMENT" was found following "end". Expected tokens may include: "JOIN \". SQLSTATE=42601 调用存储过程: \[db2inst1@t3-dtpoc-dtpoc-web04 liys\]$ db2 "select count(\*) from log_test" 1 ----------- 260000 1 record(s) selected. \[db2inst1@t3-dtpoc-dtpoc-web04 liys\]$ db2 "call insert_log_test()" Return Status = 0 \[db2inst1@t3-dtpoc-dtpoc-web04 liys\]$ db2 "select count(\*) from log_test" 1 ----------- 270000 1 record(s) selected. db2 "call insert_log_test()"执行的很快,不到1秒就插入成功了,而MYSQL相同的存储过程需要大概26秒左右,没想到会这么慢。。。 直接执行存储过程:返回结果也很快,不到1秒。 \[db2inst1@t3-dtpoc-dtpoc-web04 \~\]$ db2 "begin atomic declare i int default 0;while(i \<10000) do insert into log_test values (i,'中间提交的事务');set i=i+1;end while;end" DB20000I The SQL command completed successfully. 来看看MYSQL为啥这么慢,首先看他的存储过程定义: vi insert_log_test.sql delimiter // #定义标识符为双斜杠 drop procedure if exists insert_log_test; #如果存在test存储过程则删除 create procedure insert_log_test() #创建无参存储过程,名称为test begin declare i int; #申明变量 set i = 0; #变量赋值 while i \< 10000 do #结束循环的条件: 当i大于10时跳出while循环 insert into log_test values (i,'中间提交的事务+++++++++\*\*\*\*\*\*\*\*\*\*++++++++:q'); #往test表添加数据 set i = i + 1; #循环一次,i加一 end while; #结束while循环 end // #结束定义语句 插入10000条需要21秒多 mysql\> call insert_log_test(); Query OK, 1 row affected (21.43 sec) 什么原因呢?怀疑是每插入一条就commit一次,一共commit了10000次,而DB2是插入10000条后提交了一次而已,下面来验证下 vi insert_log_test.sql delimiter // drop procedure if exists insert_log_test; create procedure insert_log_test() begin declare i int; set i = 0; start transaction; while i \< 10000 do insert into log_test values (i,'中间提交的事务+++++++++\*\*\*\*\*\*\*\*\*\*++++++++'); set i = i + 1; end while; commit; end// delimiter ; mysql\> source /home/mysql/liys/insert_log_test.sql; Query OK, 0 rows affected, 1 warning (0.00 sec) Query OK, 0 rows affected (0.00 sec) mysql\> call insert_log_test(); Query OK, 0 rows affected (0.26 sec) mysql\> select count(\*) from log_test; +----------+ \| count(\*) \| +----------+ \| 410000 \| +----------+ 1 row in set (0.15 sec) mysql\> call insert_log_test(); Query OK, 0 rows affected (0.27 sec) mysql\> select count(\*) from log_test; +----------+ \| count(\*) \| +----------+ \| 420000 \| +----------+ 1 row in set (0.15 sec) 结果证明猜想是对的

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