【标题】：Peeking in MySQL 5.0 Enterprise Functional
【关键字】：c,SQL,in,io,is,Function,on,My,Enterprise,MySQL,Peeking,in,MySQL,Enterprise
【来源】：网络

Peeking in MySQL 5.0 Enterprise Functional

MySQL5.0 Alpha 發佈, 我們期待已久的 Create Function 和 Create Procedure 的功能終於有了. 詳細的資訊請參考 MySQL AB 的官方網站的新聞. 早就想要的功能,出來了還不趕快試試....

本文以 Windows XP PRO os 為例< :) 我可不是有意來替 M$ 宣傳,只是我用的是 Windows,沒有辦法啦>來說明,其它OS 類同, 先下載 MySQL5.0, 為了免除安裝,我們直接下載 Without installer (unzip in C:\) 的版本,到 http://www.mysql.com/downloads/mysql-5.0.html 下載.

1. 直接 unzip 後把其放到 C:\ 下, 並把 root Directory 改為 mysql(不改也可,那在 my.ini 中要把其中的 mysql 改為你的實際名稱)

2. 下面是 my.ini 的配置文件,如果你對配置不熟的話,你可以直接 Copy 過去存為 my.ini 後放到 C:\windows 下即可 (我電腦的 RAM = 256)
========================================================================================================
# Example mysql config file.
# Copy this file to c:\my.cnf to set global options
#
# One can use all long options that the program supports.
# Run the program with --help to get a list of available options

# This will be passed to all mysql clients
[client]
#password=my_password
port=3306
#socket=MySQL

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# The MySQL server
[mysqld]
port=3306
#socket=MySQL
skip-locking
set-variable = key_buffer=16M
set-variable = max_allowed_packet=1M
set-variable = table_cache=64
set-variable = sort_buffer=512K
set-variable = net_buffer_length=8K
set-variable = myisam_sort_buffer_size=8M
server-id = 1

# Uncomment the following if you want to log updates
#log-bin

# Uncomment the following rows if you move the MySQL distribution to another
# location
#basedir = d:/mysql/
#datadir = d:/mysql/data/

# Uncomment the following if you are NOT using BDB tables
#skip-bdb

# Uncomment the following if you are using BDB tables
#set-variable = bdb_cache_size=4M
#set-variable = bdb_max_lock=10000

# Uncomment the following if you are using Innobase tables
innodb_data_file_path = ibdata1:400M
innodb_data_home_dir = C:/mysql/InnoDB/ibdata # InnoDB 及 ibdata 的資料夾你要自己動手
innodb_log_group_home_dir = C:/mysql/InnoDB/iblogs # iblogs 的資料夾同樣你要自己動手
innodb_log_arch_dir = C:/mysql/innodb/iblogs
set-variable = innodb_mirrored_log_groups=1
set-variable = innodb_log_files_in_group=3
set-variable = innodb_log_file_size=5M
set-variable = innodb_log_buffer_size=8M
innodb_flush_log_at_trx_commit=1
innodb_log_archive=0
set-variable = innodb_buffer_pool_size=16M
set-variable = innodb_additional_mem_pool_size=2M
set-variable = innodb_file_io_threads=4
set-variable = innodb_lock_wait_timeout=50

[mysqldump]
quick
set-variable = max_allowed_packet=16M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[isamchk]
set-variable = key_buffer=20M
set-variable = sort_buffer=20M
set-variable = read_buffer=2M
set-variable = write_buffer=2M

[myisamchk]
set-variable = key_buffer=20M
set-variable = sort_buffer=20M
set-variable = read_buffer=2M
set-variable = write_buffer=2M

[mysqlhotcopy]
interactive-timeout
[WinMySQLAdmin]
Server=C:/mysql/bin/mysqld-nt.exe
============================================================================

3. Create InnoDB table table space 如果運行沒有問題,你應該可以看到如下內容:
==========================================================

C:\mysql\bin>mysqld --console
InnoDB: The first specified data file C:\mysql\InnoDB\ibdata\ibdata1 did not exist:
InnoDB: a new database to be created!
040113 15:12:54 InnoDB: Setting file C:\mysql\InnoDB\ibdata\ibdata1 size to 400 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Progress in MB: 100 200 300 400
040113 15:13:19 InnoDB: Log file C:\mysql\InnoDB\iblogs\ib_logfile0 did not exist: new to be created
InnoDB: Setting log file C:\mysql\InnoDB\iblogs\ib_logfile0 size to 5 MB
InnoDB: Database physically writes the file full: wait...
040113 15:13:19 InnoDB: Log file C:\mysql\InnoDB\iblogs\ib_logfile1 did not exist: new to be created
InnoDB: Setting log file C:\mysql\InnoDB\iblogs\ib_logfile1 size to 5 MB
InnoDB: Database physically writes the file full: wait...
040113 15:13:20 InnoDB: Log file C:\mysql\InnoDB\iblogs\ib_logfile2 did not exist: new to be created
InnoDB: Setting log file C:\mysql\InnoDB\iblogs\ib_logfile2 size to 5 MB
InnoDB: Database physically writes the file full: wait...
InnoDB: Doublewrite buffer not found: creating new
InnoDB: Doublewrite buffer created
InnoDB: Creating foreign key constraint system tables
InnoDB: Foreign key constraint system tables created
040113 15:13:26 InnoDB: Started; log sequence number 0 0
mysqld: ready for connections.
Version: '5.0.0-alpha-max-debug' socket: '' port: 3306
==========================================================

安裝 Ok, 進去看看吧,沒想到一進 Mysql 馬上就來了個下馬威, 原來的 '' 這個 user 不能用 mysql 的 databases
=========================================================
C:\mysql\bin>mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 2 to server version: 5.0.0-alpha-max-debug

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> use mysql
ERROR 1044 (42000): Access denied for user: ''@'localhost' to database 'mysql
==========================================================

沒有辦法,只有用 root 進去:

==========================================================

C:\mysql\bin>mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5 to server version: 5.0.0-alpha-max-debug

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>

==========================================================

:) root 的密碼還是勤快一點把它改掉吧

4. 體驗一下 Create Function 吧

CREATE FUNCTION MyFunc (s CHAR(20)) RETURNS CHAR(50) RETURN CONCAT('Hello ',s,' DLL',' !');

==========================================================
mysql> CREATE FUNCTION MyFunc (s CHAR(20)) RETURNS CHAR(50) RETURN CONCAT('Hello
',s,'.Lan',' !');
Query OK, 0 rows affected (0.00 sec)

mysql>

mysql> select MyFunc('Dennis');
+--------------------+
| MyFunc('Dennis') |
+--------------------+
| Hello Dennis.Lan ! |
+--------------------+
1 row in set (0.01 sec)

mysql>

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5. Drop Function

==========================================================
mysql> drop function MyFunc;
Query OK, 0 rows affected (0.00 sec)

mysql>

==========================================================

6. Create 一個 Procedure 試試吧!

CREATE PROCEDURE MyProc (OUT param1 INT) BEGIN SELECT COUNT(*) INTO param1 FROM sys_forms; END;

千萬記住,下面這樣子不行喲, 我試了 n 次, 每次都是錯誤, 我還以為 Mysql 有問題呢,原來不是

==========================================================

mysql> use test;
Database changed
mysql> CREATE PROCEDURE MyProc (OUT param1 INT) BEGIN SELECT COUNT(*) INTO param
1 FROM sys_forms; END;

ERROR 1064 (42000): You have an error in your SQL syntax. Check the manual that
corresponds to your MySQL server version for the right syntax to use near 'SELE
CT COUNT(*) INTO param1 FROM sys_forms' at line 1

==========================================================

正確的做法是:
==========================================================
mysql> delimiter | # 因為你的 Procedure 或 Function中難免會用到 ";" 作為 sql statement 的結束符, 所以還是請你把這個結束符號改一下吧,不然就會出現上面的 error 1064(42000)

mysql> CREATE PROCEDURE MyProc (OUT param1 INT) BEGIN SELECT COUNT(*) INTO param1 FROM mysql.user; END;
-> |
Query OK, 0 rows affected (0.00 sec)

==========================================================

OK, 你的成功了嗎?

強烈建議你先看看這個 http://www.mysql.com/doc/en/CREATE_PROCEDURE.html

Procedure Create 成功了,測試一下吧!
Step 1:
==========================================================

mysql> CALL MyProc(@a)|
Query OK, 0 rows affected (0.01 sec)
==========================================================

Step 2:
==========================================================

mysql> select @a;
-> |
+------+
| @a |
+------+
| 0 |
+------+
1 row in set (0.00 sec)

mysql>

==========================================================

來個完整的:

==========================================================