中秋提前下班,说数据库函数无法创建。数据库没的说,指定用户指定ip访问指定数据库全部权限。

排查一下,发现数据库函数功能没有打开。函数这个问题吧,其实自己手动开启就行,比较简单。


1、查看数据库函数功能是否开启:

mysql> show variables like '%func%';
+---------------------------------+-------+
| Variable_name                   | Value |
+---------------------------------+-------+
| log_bin_trust_function_creators | OFF   |
+---------------------------------+-------+
1 row in set (0.00 sec)

注意:OFF,说明并没有开启;
mysql>

2、开启和关闭函数功能:


开启:

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>

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关闭:

SET GLOBAL log_bin_trust_function_creators=0;


问题:

上面命令行修改只是临时生效,数据库重启后仍然失效。

永久解决方案:

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

保存 ,重启服务器。

# service mysqld restart


3、谈谈命令行函数如何创建:(用工具的话指定简单许多)


查看数据库中所有的函数:

mysql> SHOW FUNCTION STATUS;

Empty set (0.00 sec)

mysql>


语法:(尊重原创,摘自:)

http://blog.csdn.net/jssg_tzw/article/details/39694489

CREATE FUNCTION func_name ( [func_parameter] ) //括号是必须的,参数是可选的  

RETURNS type  

[ characteristic ...] routine_body  


CREATE FUNCTION 用来创建函数的关键字;

func_name 表示函数的名称;

func_parameters为函数的参数列表,参数列表的形式为:[IN|OUT|INOUT] param_name type

IN:表示输入参数;

OUT:表示输出参数;

INOUT:表示既可以输入也可以输出;

param_name:表示参数的名称;

type:表示参数的类型,该类型可以是MySQL数据库中的任意类型;

RETURNS type:语句表示函数返回数据的类型;

characteristic: 指定存储函数的特性,取值与存储过程时相同,详细请访问-MySQL存储过程使用;

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)


谈谈MySQL的函数问题!_第1张图片


创建函数-根据ID获取员工姓名与员工工资:

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)


查看:
mysql> select GetEmployeeInformationByID(1);
+-----------------------------------------+
| GetEmployeeInformationByID(1)           |
+-----------------------------------------+
| employee name:David Tian---salary: 7500 |
+-----------------------------------------+
1 row in set (0.00 sec)

mysql>