// 把editUser類比成一個(gè)存儲(chǔ)過程
public void editUser(User user,String username){
    String a = "nihao";
    user.setUsername(username);
}
main(){
    User user = new User();
 editUser(user,"張三");
    user.getUseranme();   //java基礎(chǔ)
}

delimiter $$ --聲明結(jié)束符

#### 3.0 語法結(jié)構(gòu)
```sql
-- 存儲(chǔ)過程結(jié)構(gòu)
CREATE
    [DEFINER = user]
 PROCEDURE sp_name ([proc_parameter[,...]])
    [characteristic ...] routine_body
    
-- 1. proc_parameter參數(shù)部分，可以如下書寫：
 [ IN | OUT | INOUT ] param_name type
 -- type類型可以是MySQL支持的所有類型
 
-- 2. routine_body(程序體)部分，可以書寫合法的SQL語句 BEGIN ... END

-- 聲明結(jié)束符。因?yàn)镸ySQL默認(rèn)使用‘;'作為結(jié)束符，而在存儲(chǔ)過程中，會(huì)使用‘;'作為一段語句的結(jié)束，導(dǎo)致‘;'使用沖突
delimiter $$
CREATE PROCEDURE hello_procedure ()
BEGIN
 SELECT 'hello procedure';
END $$
call hello_procedure();

-- set賦值
delimiter $$
create procedure sp_var01()
begin
 declare nickname varchar(32) default 'unkown';
 set nickname = 'ZS';
 -- set nickname := 'SF';
 select nickname;
end$$
-- into賦值
delimiter $$
create procedure sp_var_into()
begin
 declare emp_name varchar(32) default 'unkown' ;
 declare emp_no int default 0;
 select e.empno,e.ename into emp_no,emp_name from emp e where e.empno = 7839;
 select emp_no,emp_name;
end$$

-- 賦值
delimiter $$
create procedure sp_var02()
begin
 set @nickname = 'ZS';
 -- set nickname := 'SF';
end$$
call sp_var02() $$
select @nickname$$  --可以看到結(jié)果

show session variables; -- 查看會(huì)話變量
select @@session.unique_checks; -- 查看某會(huì)話變量
set @@session.unique_checks = 0; --修改會(huì)話變量

show global variables like '%char%'; 
-- 查看全局變量character_set_client的值
select @@global.character_set_client; 

-- 語法
IF search_condition THEN statement_list
    [ELSEIF search_condition THEN statement_list] ...
    [ELSE statement_list]
END IF

-- 前置知識(shí)點(diǎn)：timestampdiff(unit,exp1,exp2) 取差值exp2-exp1差值，單位是unit
select timestampdiff(year,e.hiredate,now()) from emp e where e.empno = '7499         ';
delimiter $$
-- DROP PROCEDURE IF EXISTS sp_param04;
create procedure sp_param05(in ages timestamp)
begin
 declare result varchar(32);
 if timestampdiff(year,ages,now())>40 
  then set result = '元老';
 elseif timestampdiff(year,ages,now())>38 
  then set result = '老員工';
 ELSE 
  SET result = '新手';
 end if;
 select result;
end $$
delimiter;
 
call sp_param05('1970-02-26 10:00:25');
-- 注意：MYSQL時(shí)間戳必須從1970年開始。

-- 語法一（類比java的switch）：
CASE case_value
    WHEN when_value THEN statement_list
    [WHEN when_value THEN statement_list] ...
    [ELSE statement_list]
END CASE
-- 語法二：
CASE
    WHEN search_condition THEN statement_list
    [WHEN search_condition THEN statement_list] ...
    [ELSE statement_list]
END CASE

-- 需求：入職年限年齡<=38是新手 >38并 <=40老員工 >40元老
delimiter $$
create procedure sp_hire_case()
begin
 declare result varchar(32);
 declare message varchar(64);
 case
    when timestampdiff(year,'2001-01-01',now()) > 40 
  then 
   set result = '元老';
   set message = '老爺爺';
 when timestampdiff(year,'2001-01-01',now()) > 38
  then 
   set result = '老員工';
   set message = '油膩中年人';
 else 
  set result = '新手';
  set message = '萌新';
 end case;
 select result;
end$$
delimiter ;

-- 語法
[begin_label:] LOOP
    statement_list
END LOOP [end_label]

--需求：循環(huán)打印1到10
-- leave控制循環(huán)的退出
delimiter $$
create procedure sp_flow_loop()
begin
 declare c_index int default 1;
 declare result_str  varchar(256) default '1';
 cnt:loop
 
  if c_index >= 10
  then leave cnt;
  end if;
  set c_index = c_index + 1;
  set result_str = concat(result_str,',',c_index);
  
 end loop cnt;
 
 select result_str;
end$$
-- iterate + leave控制循環(huán)
delimiter $$
create procedure sp_flow_loop02()
begin
 declare c_index int default 1;
 declare result_str  varchar(256) default '1';
 cnt:loop
  set c_index = c_index + 1;
  set result_str = concat(result_str,',',c_index);
  if c_index < 10 then 
   iterate cnt; 
  end if;
  -- 下面這句話能否執(zhí)行到？什么時(shí)候執(zhí)行到？ 當(dāng)c_index < 10為false時(shí)執(zhí)行
  leave cnt;
  
 end loop cnt;
 select result_str;
 
end$$

[begin_label:] REPEAT
    statement_list
UNTIL search_condition -- 直到…為止，才退出循環(huán)
END REPEAT [end_label]
-- 需求：循環(huán)打印1到10
delimiter $$
create procedure sp_flow_repeat()
begin
 declare c_index int default 1;
 -- 收集結(jié)果字符串
 declare result_str varchar(256) default '1';
 count_lab:repeat
  set c_index = c_index + 1;
  set result_str = concat(result_str,',',c_index);
  until c_index >= 10
 end repeat count_lab;
 select result_str;
end$$

類比java的while(){}
[begin_label:] WHILE search_condition DO
    statement_list
END WHILE [end_label]
-- 需求：循環(huán)打印1到10
delimiter $$
create procedure sp_flow_while()
begin
 declare c_index int default 1;
 -- 收集結(jié)果字符串
 declare result_str varchar(256) default '1';
 while c_index < 10 do
  set c_index = c_index + 1;
  set result_str = concat(result_str,',',c_index);
 end while;
 select result_str;
end$$

類比java的breake
-- 退出 LEAVE can be used within BEGIN ... END or loop constructs (LOOP, REPEAT, WHILE).
LEAVE label

類比java的continue
-- 繼續(xù)循環(huán) ITERATE can appear only within LOOP, REPEAT, and WHILE statements
ITERATE label

類比jdbc的ResultSet
-- 聲明語法
DECLARE cursor_name CURSOR FOR select_statement
-- 打開語法
OPEN cursor_name
-- 取值語法
FETCH cursor_name INTO var_name [, var_name] ...
-- 關(guān)閉語法
CLOSE cursor_name
-- 需求：按照部門名稱查詢員工，通過select查看員工的編號(hào)、姓名、薪資。（注意，此處僅僅演示游標(biāo)用法）
-- 更改結(jié)束符為$$
delimiter $$
-- 創(chuàng)造存儲(chǔ)過程(帶一個(gè)入?yún)?
create procedure sp_create_table02(in dept_name varchar(32))
begin
-- 必須先聲明變量
 declare e_no int;
 declare e_name varchar(32);
 declare e_sal decimal(7,2);
 
 declare lp_flag boolean default true;
-- 其次聲明游標(biāo):游標(biāo)值為query（dept_name)得到的table(e.empno,e.ename,e.sal)
 declare emp_cursor cursor for 
  select e.empno,e.ename,e.sal
  from emp e,dept d
  where e.deptno = d.deptno and d.dname = dept_name;
  
-- 然后聲明 handler 句柄：
-- 關(guān)于句柄:https://blog.csdn.net/qq_43427482/article/details/109898934
-- 看完還沒理解，再看：https://www.cnblogs.com/phpper/p/7587556.html
-- 這里涉及了SQL STATE:https://blog.csdn.net/u014653854/article/details/78986780
-- 聲明handler句柄:當(dāng)每條SQL傳遞ERROR STATE為沒有值的報(bào)錯(cuò)時(shí)，設(shè)定變量lp_flag為非真，同時(shí)繼續(xù)執(zhí)行SQL（如不聲明，當(dāng)某條循環(huán)報(bào)錯(cuò)時(shí)，整個(gè)SQL將直接停止循環(huán)）
 declare continue handler for NOT FOUND set lp_flag = false;
-- 打開游標(biāo)
 open emp_cursor;
-- 開啟LOOP循環(huán)：emp_loop
 emp_loop:loop
-- 將游標(biāo)值傳遞給三個(gè)變量
  fetch emp_cursor into e_no,e_name,e_sal;
-- 如果變量lp_flag為真，則獲取這三個(gè)參數(shù)的值；否則打斷emp_loop循環(huán)
  if lp_flag then
   select e_no,e_name,e_sal;
  else
   leave emp_loop;
  end if;
-- 結(jié)束循環(huán)
 end loop emp_loop;
-- 定義用戶變量并賦值（用戶變量不需要提前聲明、僅當(dāng)前會(huì)話有效）>鄙人沒有理解這一步什么意義
 set @end_falg = 'exit_flag';
-- 關(guān)閉游標(biāo)
 close emp_cursor;
-- 結(jié)束存儲(chǔ)過程
end$$
-- 恢復(fù);結(jié)束符
delimiter;
-- 使用該存儲(chǔ)過程并傳參
call sp_create_table02('RESEARCH');

DECLARE handler_action HANDLER
    FOR condition_value [, condition_value] ...
    statement
handler_action: {
    CONTINUE  -- 繼續(xù)執(zhí)行
  | EXIT      -- 退出執(zhí)行
  | UNDO      -- 什么都不做
}
CONTINUE: Execution of the current program continues. -- 繼續(xù)執(zhí)行當(dāng)前程序
EXIT: Execution terminates for the BEGIN ... END compound statement in which the handler is declared. This is true even if the condition occurs in an inner block. -- 停止執(zhí)行在handler被聲明的BEGIN... END的組合程序，即使是在程序內(nèi)部發(fā)生該條件。
condition_value: {
    mysql_error_code
  | SQLSTATE [VALUE] sqlstate_value
  | condition_name
  | SQLWARNING
  | NOT FOUND
  | SQLEXCEPTION
}
SQLWARNING: Shorthand for the class of SQLSTATE values that begin with '01'. -- 即SQL STATE以01開頭的集合代稱
NOT FOUND: Shorthand for the class of SQLSTATE values that begin with '02'. -- 即SQL STATE以O(shè)2開頭的集合代稱
SQLEXCEPTION: Shorthand for the class of SQLSTATE values that do not begin with '00', '01', or '02'. -- 即SQL STATE不以00、01、02開頭的集合代稱
-- 各種寫法：
 DECLARE exit HANDLER FOR SQLSTATE '42S01' set @res_table = 'EXISTS';
 DECLARE continue HANDLER FOR 1050 set @res_table = 'EXISTS';
 DECLARE continue HANDLER FOR not found set @res_table = 'EXISTS';

delimiter // -- 定義結(jié)束符
create procedure high_sal(in dept_name varchar(32)) -- 創(chuàng)建存儲(chǔ)過程
begin -- 開始存儲(chǔ)過程
 declare e_no int; -- 聲明變量
 declare e_name varchar(32);
 declare e_sal decimal(7,2);
 
 declare lp_flag boolean default true;
 
 declare emp_cursor cursor for  -- 聲明游標(biāo)
  select e.empno,e.ename,e.sal
  from emp e,dept d
  where e.deptno = d.deptno and d.dname = dept_name;
  
 -- 聲明handler句柄（條件處理）
 declare continue handler for NOT FOUND set lp_flag = false;
  
 open emp_cursor; -- 打開游標(biāo)
 
 emp_loop:loop -- 開啟循環(huán)
  fetch emp_cursor into e_no,e_name,e_sal; -- 變量賦值
  
  if lp_flag then -- 流程控制
   if e_name = 'king' then 
    iterate emp_loop; -- 繼續(xù)循環(huán)
   else 
    update emp e set e.sal = e.sal + 100 where e.empno = e_no; -- 更新數(shù)據(jù)
   end if;
  else
   leave emp_loop; -- 離開循環(huán)
  end if; -- 結(jié)束流程
  
 end loop emp_loop; -- 結(jié)束循環(huán)
 set @end_falg = 'exit_flag'; -- 聲明用戶變量
 close emp_cursor; -- 變比游標(biāo)
end // -- 結(jié)束存儲(chǔ)過程
delimiter; -- 恢復(fù)結(jié)束符

call high_sal('ACCOUNTING');

-- 知識(shí)點(diǎn) 預(yù)處理 prepare語句from后使用局部變量會(huì)報(bào)錯(cuò) 
-- https://dev.mysql.com/doc/refman/5.6/en/sql-prepared-statements.html
-- 看不懂英文文檔的看這個(gè)：https://www.cnblogs.com/geaozhang/p/9891338.html；話說我也該去做一點(diǎn)英文技術(shù)文檔的閱讀提升了
PREPARE stmt_name FROM preparable_stmt
EXECUTE stmt_name [USING @var_name [, @var_name] ...]
{DEALLOCATE | DROP} PREPARE stmt_name
-- 貼一段預(yù)處理的案例，需求是：利用字符串定義預(yù)處理 SQL (直角三角形斜邊hypotenuse計(jì)算)
PREPARE stmt1 FROM 'SELECT SQRT(POW(?,2) + POW(?,2)) AS hypotenuse'; -- POW(x,y)函數(shù),用于計(jì)算x的y次方（http://c.biancheng.net/mysql/pow_power.html）；SQRT函數(shù)用于求平方根（https://blog.csdn.net/weixin_39554172/article/details/113124290）
SET @a = 3;
SET @b = 4;  -- 用戶變量使用即聲明
EXECUTE stmt1 USING @a, @b; -- 結(jié)果為5
DEALLOCATE PREPARE stmt1; 
-- 知識(shí)點(diǎn) 時(shí)間的處理
-- EXTRACT(unit FROM date)截取時(shí)間的指定位置值
-- DATE_ADD(date,INTERVAL expr unit)  日期運(yùn)算
-- LAST_DAY(date)  獲取日期的最后一天的日期
-- YEAR(date) 返回日期中的年
-- MONTH(date) 返回日期的月
-- DAYOFMONTH(date) 返回日 -- 注：根據(jù)https://stackoverflow.com/questions/35838321/day-vs-dayofmonth-in-mysql，其實(shí)DAY(date)效果是一樣的
-- 思路：循環(huán)構(gòu)建表名 comp_2020_05_01 到 comp_2020_05_31；并執(zhí)行create語句。
-- 分析：1. 循環(huán)構(gòu)筑表，僅表名不同，考慮使用存儲(chǔ)過程執(zhí)行循環(huán)處理、使用預(yù)處理提高效率。 2. 首先需要一個(gè)變量存儲(chǔ)執(zhí)行SQL；然后年份需要一個(gè)變量、月份需要一個(gè)變量、日期需要一個(gè)變量、拼接出來的表名需要一個(gè)變量；除此之外，還需要一個(gè)數(shù)字用來累增；至此，我們得到了至少需要6個(gè)變量。為了補(bǔ)全日期0，增加兩個(gè)月份、日的變量用來補(bǔ)充0形成01、02···。 3. 考慮到預(yù)處的格式（from后不能有局部變量）,寫7個(gè)局部變量，1個(gè)用戶變量
delimiter //  --聲明結(jié)束符
create procedure sp_create_table()
begin
--  定義一堆局部變量
 declare next_year int;
 declare next_month int;
 declare next_month_maxday int;
  
 declare next_month_str char(2);
 declare next_month_maxday_str char(2);
 
 -- 處理每天的表名
 declare table_name_str char(10);
 -- 統(tǒng)計(jì)序列
 declare t_index int default 1;
 -- declare create_table_sql varchar(200);
 
 -- 獲取下個(gè)月的年份
 set next_year = year(date_add(now(),INTERVAL 1 month));
 -- 獲取下個(gè)月是幾月 
 set next_month = month(date_add(now(),INTERVAL 1 month));
 -- 下個(gè)月最后一天是幾號(hào)
 set next_month_maxday = dayofmonth(LAST_DAY(date_add(now(),INTERVAL 1 month)));
 
 -- 把1-9月補(bǔ)上0:  01,02····，09
 if next_month < 10
  then set next_month_str = concat('0',next_month);
 else
  set next_month_str = concat('',next_month);
 end if;
 
 
 while t_index <= next_month_maxday do
  
  -- 同上，對(duì)天數(shù)補(bǔ)0
  if (t_index < 10)
   then set next_month_maxday_str = concat('0',t_index);
  else
   set next_month_maxday_str = concat('',t_index);
  end if;
  
  -- 2020_05_01
  set table_name_str = concat(next_year,'_',next_month_str,'_',next_month_maxday_str);
  -- 拼接create sql語句（用戶變量）
  set @create_table_sql = concat(
     'create table comp_',
     table_name_str,
     '(`grade` INT(11) NULL,`losal` INT(11) NULL,`hisal` INT(11) NULL) COLLATE=\'utf8_general_ci\' ENGINE=InnoDB');
  -- FROM后面不能使用局部變量！這就是我們?yōu)槭裁词褂糜脩糇兞康脑?  prepare create_table_stmt FROM @create_table_sql;
  execute create_table_stmt;
  DEALLOCATE prepare create_table_stmt;
  
  set t_index = t_index + 1;
  
 end while; 
end//
delimiter;
call sp_create_table()
-- 以下為個(gè)人精簡(jiǎn)版
delimiter //
CREATE PROCEDURE sp_createtable1 () BEGIN-- 統(tǒng)計(jì)序列
 DECLARE
  t_index INT DEFAULT 1;
 WHILE
   t_index <= DAY (
    LAST_DAY(
    date_add( now(), INTERVAL 1 MONTH ))) DO
   
   SET @create_table_sql = concat(
    'CREATE TABLE comp_',
    YEAR (
    date_add( now(), INTERVAL 1 MONTH )),
    '_',
    MONTH (
    date_add( now(), INTERVAL 1 MONTH )),
    '_',
    t_index,
    '(`grade` INT(11) NULL,`losal` INT(11) NULL,`hisal` INT(11) NULL) COLLATE=\'utf8_general_ci\' ENGINE=InnoDB' 
   );-- FROM后面不能使用局部變量！這就是我們?yōu)槭裁词褂糜脩糇兞康脑?  PREPARE create_table_stmt 
  FROM
   @create_table_sql;
  EXECUTE create_table_stmt;
  DEALLOCATE PREPARE create_table_stmt;
  
  SET t_index = t_index + 1;
  
 END WHILE;
 
END // 
delimiter;
CALL sp_createtable1 ()

characteristic:
    COMMENT 'string'
  | LANGUAGE SQL
  | [NOT] DETERMINISTIC
  | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
  | SQL SECURITY { DEFINER | INVOKER }

-- 如有死循環(huán)處理，可以通過下面的命令查看并結(jié)束
show processlist;
kill id;

https://dev.mysql.com/doc/refman/5.6/en/control-flow-functions.html
select 
 case
  when timestampdiff(year,e.hiredate,now()) <= 38 then '新手'
  when timestampdiff(year,e.hiredate,now()) <= 40 then '老員工'
  else '元老'
 end hir_loc,
 e.*
from emp e;

create temporary table 表名(
　　字段名 類型 [約束],
　　name varchar(20) 
)Engine=InnoDB default charset utf8;
-- 需求：按照部門名稱查詢員工，通過select查看員工的編號(hào)、姓名、薪資。（注意，此處僅僅演示游標(biāo)用法）
delimiter $$
create procedure sp_create_table02(in dept_name varchar(32))
begin
 declare emp_no int;
 declare emp_name varchar(32);
 declare emp_sal decimal(7,2);
 declare exit_flag int default 0;
 
 declare emp_cursor cursor for
  select e.empno,e.ename,e.sal
  from emp e inner join dept d on e.deptno = d.deptno where d.dname = dept_name;
 
 declare continue handler for not found set exit_flag = 1;
 
 -- 創(chuàng)建臨時(shí)表收集數(shù)據(jù)
 CREATE temporary TABLE `temp_table_emp` (
  `empno` INT(11) NOT NULL COMMENT '員工編號(hào)',
  `ename` VARCHAR(32) NULL COMMENT '員工姓名' COLLATE 'utf8_general_ci',
  `sal` DECIMAL(7,2) NOT NULL DEFAULT '0.00' COMMENT '薪資',
  PRIMARY KEY (`empno`) USING BTREE
 )
 COLLATE='utf8_general_ci'
 ENGINE=InnoDB; 
 
 open emp_cursor;
 
 c_loop:loop
  fetch emp_cursor into emp_no,emp_name,emp_sal;
  
  
  if exit_flag != 1 then
   insert into temp_table_emp values(emp_no,emp_name,emp_sal); 
  else
   leave c_loop;
  end if;
  
 end loop c_loop;
 
 select * from temp_table_emp;
 
 select @sex_res; -- 僅僅是看一下會(huì)不會(huì)執(zhí)行到
 close emp_cursor;
 
end$$
call sp_create_table02('RESEARCH');

CREATE TABLE `dept` (
 `deptno` INT(11) NOT NULL COMMENT '部門編號(hào)',
 `dname` VARCHAR(32) NULL COMMENT '部門名稱' COLLATE 'utf8_general_ci',
 `loc` VARCHAR(64) NULL COMMENT '部門地址' COLLATE 'utf8_general_ci',
 PRIMARY KEY (`deptno`) USING BTREE
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
;
INSERT INTO DEPT VALUES
 (10,'ACCOUNTING','NEW YORK');
INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS');
INSERT INTO DEPT VALUES
 (30,'SALES','CHICAGO');
INSERT INTO DEPT VALUES
 (40,'OPERATIONS','BOSTON');
 
CREATE TABLE `emp` (
 `empno` INT(11) NOT NULL COMMENT '員工編號(hào)',
 `ename` VARCHAR(32) NULL COMMENT '員工姓名' COLLATE 'utf8_general_ci',
 `job` VARCHAR(10) NULL COMMENT '職位' COLLATE 'utf8_general_ci',
 `mgr` INT(11) NULL COMMENT '上級(jí)編號(hào)',
 `hiredate` DATE NOT NULL COMMENT '入職時(shí)間',
 `sal` DECIMAL(7,2) NOT NULL DEFAULT '0.00' COMMENT '薪資',
 `comm` DECIMAL(7,2) NULL COMMENT '年終獎(jiǎng)金',
 `deptno` INT(11) NOT NULL COMMENT '部門編號(hào)',
 PRIMARY KEY (`empno`) USING BTREE,
 INDEX `FK_emp_dept` (`deptno`) USING BTREE,
 CONSTRAINT `FK_emp_dept` FOREIGN KEY (`deptno`) REFERENCES `procedure_demo`.`dept` (`deptno`) ON UPDATE RESTRICT ON DELETE RESTRICT
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
;
insert into emp values
(7369,'smith','clerk',7902,'1980-12-17',800,null,20);
insert into emp values
(7499,'allen','salesman',7698,'1981-02-20',1600,300,30);
insert into emp values
(7521,'ward','salesman',7698,'1981-02-22',1250,500,30);
insert into emp values
(7566,'jones','manager',7839,'1981-02-04',2975,null,20);
insert into emp values
(7654,'martin','salesman',7698,'1981-09-28',1250,1400,30);
insert into emp values
(7698,'blake','manager',7839,'1981-05-01',2850,null,30);
insert into emp values
(7782,'clark','manager',7839,'1981-06-09',2450,null,10);
insert into emp values
(7788,'scott','analyst',7566,'1987-07-13')-85,3000,null,20);
insert into emp values
(7839,'king','president',null,'1981-11-17',5000,null,10);
insert into emp values
(7844,'turner','salesman',7698,'1981-09-08',1500,0,30);
insert into emp values
(7876,'adams','clerk',7788,'1987-07-13')-51,1100,null,20);
insert into emp values
(7900,'james','clerk',7698,'1981-12-03',950,null,30);
insert into emp values
(7902,'ford','analyst',7566,'1981-12-03',3000,null,20);
insert into emp values
(7934,'miller','clerk',7782,'1982-01-23',1300,null,10);
CREATE TABLE `salgrade` (
 `grade` INT(11) NULL,
 `losal` INT(11) NULL,
 `hisal` INT(11) NULL
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
;
insert into salgrade values (1,700,1200);
insert into salgrade values (2,1201,1400);
insert into salgrade values (3,1401,2000);
insert into salgrade values (4,2001,3000);
insert into salgrade values (5,3001,9999);