中秋提前下班，說資料庫函數無法建立。資料庫沒的說，指定使用者指定ip通路指定資料庫全部權限。
排查一下，發現資料庫函數功能沒有打開。函數這個問題吧，其實自己手動開啟就行，比較簡單。
1、檢視資料庫函數功能是否開啟：
mysql> show variables like '%func%';
+---------------------------------+-------+
| Variable_name | Value |
+---------------------------------+-------+
| log_bin_trust_function_creators | OFF |
+---------------------------------+-------+
1 row in set (0.00 sec)
注意：OFF，說明并沒有開啟；
mysql> 2、開啟和關閉函數功能：
開啟：
SET GLOBAL log_bin_trust_function_creators=1;
mysql> SET GLOBAL log_bin_trust_function_creators=1;
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like '%func%';
+---------------------------------+-------+
| Variable_name | Value |
| log_bin_trust_function_creators | ON |
1 row in set (0.00 sec)
mysql>
關閉：
SET GLOBAL log_bin_trust_function_creators=0;
問題：
上面指令行修改隻是臨時生效，資料庫重新開機後仍然失效。
永久解決方案：
windows下my.ini
[mysqld]加上log_bin_trust_function_creators=1
linux下/etc/my.cnf下my.cnf
[mysqld]加上log_bin_trust_function_creators=1
儲存 ，重新開機伺服器。
# service mysqld restart
3、談談指令行函數如何建立：（用工具的話指定簡單許多）
檢視資料庫中所有的函數：
mysql> SHOW FUNCTION STATUS;
Empty set (0.00 sec)
文法：（尊重原創，摘自：）
http://blog.csdn.net/jssg_tzw/article/details/39694489
CREATE FUNCTION func_name ( [func_parameter] ) //括号是必須的，參數是可選的
RETURNS type
[ characteristic ...] routine_body
CREATE FUNCTION 用來建立函數的關鍵字；
func_name 表示函數的名稱；
func_parameters為函數的參數清單，參數清單的形式為：[IN|OUT|INOUT] param_name type
IN：表示輸入參數；
OUT：表示輸出參數；
INOUT：表示既可以輸入也可以輸出；
param_name：表示參數的名稱；
type：表示參數的類型，該類型可以是MySQL資料庫中的任意類型；
RETURNS type：語句表示函數傳回資料的類型；
characteristic: 指定存儲函數的特性，取值與存儲過程時相同，詳細請通路－MySQL存儲過程使用;
eg：
mysql> create database hr;
Query OK, 1 row affected (0.00 sec)
mysql> use hr;
Database changed
mysql> create table employees
-> (
-> employee_id int(11) primary key not null auto_increment,
-> employee_name varchar(50) not null,
-> employee_sex varchar(10) default '男',
-> hire_date datetime not null default current_timestamp,
-> employee_mgr int(11),
-> employee_salary float default 3000,
-> department_id int(11)
-> );
Query OK, 0 rows affected (1.17 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('David Tian','男',10,7500,1);
','女',10,5300,1);
insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Sunshine Ma','女',10,6500,2);
insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) valuesQuery OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Black Xie','男',10,6600,1);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Moses Wang','男',10,4300,1);
Query OK, 1 row affected (0.03 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Rena Ruan','女',10,5300,1);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Sunshine Ma','女',10,6500,2);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Scott Gao','男',10,9500,2);
Query OK, 1 row affected (0.01 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Warren Si','男',10,7800,2);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Kaishen Yang','男',10,9500,3);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Simon Song','男',10,5500,3);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Brown Guan','男',10,5000,3);
Query OK, 1 row affected (0.01 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Eleven Chen','女',10,3500,2);
employee_salary,department_id) values ('Cherry Zhou','女',10,5500,4);
insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Klause He','男',10,4500,5);
insert into employees(employee_name,employee_sex,eQuery OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Cherry Zhou','女',10,5500,4);
Query OK, 1 row affected (0.01 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Klause He','男',10,4500,5);
mployee_mgr,employee_salary,department_id) values ('Maven Ma','男',10,4500,6);
insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Stephani Wang','女',10,5500,7);
insert into employees(employee_name,eQuery OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Maven Ma','男',10,4500,6);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Stephani Wang','女',10,5500,7);
Query OK, 1 row affected (0.01 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Jerry Guo','男',10,8500,1);
Query OK, 1 row affected (0.00 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Gerardo Garza','男',10,25000,8);
Query OK, 1 row affected (0.01 sec)
mysql> insert into employees(employee_name,employee_sex,employee_mgr,employee_salary,department_id) values ('Derek Wu','男',10,5500,5);
Query OK, 1 row affected (0.03 sec)
mysql> select * from employees;
+-------------+---------------+--------------+---------------------+--------------+-----------------+---------------+
| employee_id | employee_name | employee_sex | hire_date | employee_mgr | employee_salary | department_id |
+-------------+---------------+--------------+---------------------+--------------+-----------------+---------------+
| 1 | David Tian | 男 | 2016-06-03 13:50:28 | 10 | 7500 | 1 |
| 2 | Black Xie | 男 | 2016-06-03 13:50:28 | 10 | 6600 | 1 |
| 3 | Moses Wang | 男 | 2016-06-03 13:50:28 | 10 | 4300 | 1 |
| 4 | Rena Ruan | 女 | 2016-06-03 13:50:28 | 10 | 5300 | 1 |
| 5 | Sunshine Ma | 女 | 2016-06-03 13:50:28 | 10 | 6500 | 2 |
| 6 | Scott Gao | 男 | 2016-06-03 13:50:28 | 10 | 9500 | 2 |
| 7 | Warren Si | 男 | 2016-06-03 13:50:28 | 10 | 7800 | 2 |
| 8 | Kaishen Yang | 男 | 2016-06-03 13:50:28 | 10 | 9500 | 3 |
| 9 | Simon Song | 男 | 2016-06-03 13:50:28 | 10 | 5500 | 3 |
| 10 | Brown Guan | 男 | 2016-06-03 13:50:28 | 10 | 5000 | 3 |
| 11 | Eleven Chen | 女 | 2016-06-03 13:50:28 | 10 | 3500 | 2 |
| 12 | Cherry Zhou | 女 | 2016-06-03 13:50:28 | 10 | 5500 | 4 |
| 13 | Klause He | 男 | 2016-06-03 13:50:28 | 10 | 4500 | 5 |
| 14 | Maven Ma | 男 | 2016-06-03 13:50:28 | 10 | 4500 | 6 |
| 15 | Stephani Wang | 女 | 2016-06-03 13:50:28 | 10 | 5500 | 7 |
| 16 | Jerry Guo | 男 | 2016-06-03 13:50:28 | 10 | 8500 | 1 |
| 17 | Gerardo Garza | 男 | 2016-06-03 13:50:28 | 10 | 25000 | 8 |
| 18 | Derek Wu | 男 | 2016-06-03 13:50:32 | 10 | 5500 | 5 |
+-------------+---------------+--------------+---------------------+--------------+-----------------+---------------+
18 rows in set (0.00 sec) 
mysql> DELIMITER //
mysql> CREATE FUNCTION GetEmployeeInformationByID(id INT)
-> RETURNS VARCHAR(300)
-> BEGIN
-> RETURN(SELECT CONCAT('employee name:',employee_name,'---','salary: ',employee_salary) FROM employees WHERE employee_id=id);
-> END//
Query OK, 0 rows affected (0.00 sec)
檢視：
mysql> select GetEmployeeInformationByID(1);
+-----------------------------------------+
| GetEmployeeInformationByID(1) |
+-----------------------------------------+
| employee name:David Tian---salary: 7500 |
+-----------------------------------------+
1 row in set (0.00 sec)
mysql>