數據庫存儲過程基本庫函數：字符串類型，數值類型，日期類型

附：函數庫
mysql存儲過程基本函數包括：字符串類型，數值類型，日期類型

一、字符串類

||            //字符串連接
CHARSET(str) //返回字串字符集
CONCAT (string2 [,… ]) //連接字串
INSTR (string ,substring ) //返回substring首次在string中出現的位置,不存在返回0
LCASE (string2 ) //轉換成小寫
LEFT (string2 ,length ) //從string2中的左邊起取length個字符
LENGTH (string ) //string長度
LOAD_FILE (file_name ) //從文件讀取內容
LOCATE (substring , string [,start_position ] ) 同INSTR,但可指定開始位置
LPAD (string2 ,length ,pad ) //重復用pad加在string開頭,直到字串長度為length
LTRIM (string2 ) //去除前端空格
REPEAT (string2 ,count ) //重復count次
REPLACE (str ,search_str ,replace_str ) //在str中用replace_str替換search_str
RPAD (string2 ,length ,pad) //在str后用pad補充,直到長度為length
RTRIM (string2 ) //去除后端空格
STRCMP (string1 ,string2 ) //逐字符比較兩字串大小,
SUBSTRING (str , position [,length ]) //從str的position開始,取length個字符,
注：mysql中處理字符串時，默認第一個字符下標為1，即參數position必須大於等於1
mysql> select substring(’abcd’,0,2);
+———————–+
| substring(’abcd’,0,2) |
+———————–+
|                       |
+———————–+
1 row in set (0.00 sec)

mysql> select substring(’abcd’,1,2);
+———————–+
| substring(’abcd’,1,2) |
+———————–+
| ab                    |
+———————–+
1 row in set (0.02 sec)

TRIM([[BOTH|LEADING|TRAILING] [padding] FROM]string2) //去除指定位置的指定字符
UCASE (string2 ) //轉換成大寫
RIGHT(string2,length) //取string2最后length個字符
SPACE(count) //生成count個空格

二、數值類型

ABS (number2 ) //絕對值
BIN (decimal_number ) //十進制轉二進制
CEILING (number2 ) //向上取整
CONV(number2,from_base,to_base) //進制轉換
FLOOR (number2 ) //向下取整
FORMAT (number,decimal_places ) //保留小數位數
HEX (DecimalNumber ) //轉十六進制
注：HEX()中可傳入字符串，則返回其ASC-11碼，如HEX(’DEF’)返回4142143
也可以傳入十進制整數，返回其十六進制編碼，如HEX(25)返回19
LEAST (number , number2 [,..]) //求最小值
MOD (numerator ,denominator ) //求余
POWER (number ,power ) //求指數
RAND([seed]) //隨機數
ROUND (number [,decimals ]) //四舍五入,decimals為小數位數]

注：返回類型並非均為整數，如：

(1)默認變為整形值
mysql> select round(1.23);
+————-+
| round(1.23) |
+————-+
|           1 |
+————-+
1 row in set (0.00 sec)

mysql> select round(1.56);
+————-+
| round(1.56) |
+————-+
|           2 |
+————-+
1 row in set (0.00 sec)

(2)可以設定小數位數，返回浮點型數據

mysql> select round(1.567,2);
+—————-+
| round(1.567,2) |
+—————-+
|           1.57 |
+—————-+
1 row in set (0.00 sec)

SIGN (number2 ) //返回符號,正負或0
SQRT(number2) //開平方

三、日期類型

ADDTIME (date2 ,time_interval ) //將time_interval加到date2
CONVERT_TZ (datetime2 ,fromTZ ,toTZ ) //轉換時區
CURRENT_DATE ( ) //當前日期
CURRENT_TIME ( ) //當前時間
CURRENT_TIMESTAMP ( ) //當前時間戳
DATE (datetime ) //返回datetime的日期部分
DATE_ADD (date2 , INTERVAL d_value d_type ) //在date2中加上日期或時間
DATE_FORMAT (datetime ,FormatCodes ) //使用formatcodes格式顯示datetime
DATE_SUB (date2 , INTERVAL d_value d_type ) //在date2上減去一個時間
DATEDIFF (date1 ,date2 ) //兩個日期差
DAY (date ) //返回日期的天
DAYNAME (date ) //英文星期
DAYOFWEEK (date ) //星期(1-7) ,1為星期天
DAYOFYEAR (date ) //一年中的第幾天
EXTRACT (interval_name FROM date ) //從date中提取日期的指定部分
MAKEDATE (year ,day ) //給出年及年中的第幾天,生成日期串
MAKETIME (hour ,minute ,second ) //生成時間串
MONTHNAME (date ) //英文月份名
NOW ( ) //當前時間
SEC_TO_TIME (seconds ) //秒數轉成時間
STR_TO_DATE (string ,format ) //字串轉成時間,以format格式顯示
TIMEDIFF (datetime1 ,datetime2 ) //兩個時間差
TIME_TO_SEC (time ) //時間轉秒數]
WEEK (date_time [,start_of_week ]) //第幾周
YEAR (datetime ) //年份
DAYOFMONTH(datetime) //月的第幾天
HOUR(datetime) //小時
LAST_DAY(date) //date的月的最后日期
MICROSECOND(datetime) //微秒
MONTH(datetime) //月
MINUTE(datetime) //分

注：可用在INTERVAL中的類型：DAY ,DAY_HOUR ,DAY_MINUTE ,DAY_SECOND ,HOUR ,HOUR_MINUTE ,HOUR_SECOND ,MINUTE ,MINUTE_SECOND,MONTH ,SECOND ,YEAR
DECLARE variable_name [,variable_name...] datatype [DEFAULT value]; 
其中，datatype為mysql的數據類型，如:INT, FLOAT, DATE, VARCHAR(length)

例：

DECLARE l_int INT unsigned default 4000000; 
DECLARE l_numeric NUMERIC(8,2) DEFAULT 9.95; 
DECLARE l_date DATE DEFAULT '1999-12-31'; 
DECLARE l_datetime DATETIME DEFAULT '1999-12-31 23:59:59';
DECLARE l_varchar VARCHAR(255) DEFAULT 'This will not be padded';

例：

create or replace procedure DS16_1FB_QUERY(ls_bbrq IN VARCHAR2,os OUT INTEGER,flag OUT INTEGER) AS
   --報表管理DS16_1FB_query.mxml電生16-1附表的查詢和編輯；
   --輸入報表日期ls_bbrq，輸出os和flag， os=0即沒有需要統計的數據!os=1統計結束!
   yf DATE;
   ls_pzbm VARCHAR2(12);
   ll_pzbm Number(12);
   
   ld_dlby Number(10,2);
   ld_dlbj Number(10,2);
   ld_dllj Number(10,2);
   
   ld_mlby Number(10,2);
   ld_mlbj Number(10,2);
   ld_mllj Number(10,2);
   
   ld_mhby Number(10,2);
   ld_mhbj Number(10,2);
   ld_mhlj Number(10,2);
   
   ld_frlby Number(10,2);
   ld_frlbj Number(10,2);
   ld_frllj Number(10,2);
   
   li_count INTEGER;
   
BEGIN
  select count(*) into li_count from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm  like '1';
  if li_count=0 then
    os:=0;--沒有需要統計的數據!
    flag:=1;
  else
   delete hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm  like '1';
   commit;
   select sum(dlby) into ld_dlby from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(dlbj) into ld_dlbj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(dllj) into ld_dllj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mlby) into ld_mlby from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mlbj) into ld_mlbj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mllj) into ld_mllj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';

   select sum(mlby*1000)/sum(dlby) into ld_mhby from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mlbj*1000)/sum(dlbj) into ld_mhbj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mllj*1000)/sum(dllj) into ld_mhlj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mlby*frlby)/sum(mlby) into ld_frlby from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mlbj*frlbj)/sum(mlbj) into ld_frlbj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   select sum(mllj*frllj)/sum(mllj) into ld_frllj from hc_d16fbbb where to_char(bbrq,'yyyymm')=ls_bbrq and rllbdm not like '1';
   
   ld_mhby:=round(ld_mhby,0);--四舍五入
   ld_mhbj:=round(ld_mhbj,0);
   ld_mhlj:=round(ld_mhlj,0);
   select max(pzbm) into ls_pzbm from hc_d16fbbb  where substr(pzbm,1,4)='0400';
   ll_pzbm:=100000000+to_number(ls_pzbm)+1;--字符串轉化為數字
   ls_pzbm:=substr(to_char(ll_pzbm),5,12); --數字轉化為字符串
   ls_pzbm:='0400' || ls_pzbm;             --字符串連接
   
   yf:=to_date(ls_bbrq||'01','YYYYMMDD');  --字符串連接
   insert into hc_d16fbbb(lmrq,bbrq,rllbdm,dlby,dlbj,dllj,mlby,mlbj,mllj,mhby,mhbj,mhlj,frlby,frlbj,frllj,pzbm)values(yf,yf,'1',ld_dlby,ld_dlbj,ld_dllj,ld_mlby,ld_mlbj,ld_mllj,ld_mhby,ld_mhbj,ld_mhlj,ld_frlby,ld_frlbj,ld_frllj,ls_pzbm);
   if sqlcode=0 then
     flag:=1;
     commit;
   else
    rollback;
    flag:=0;
   end if;
   os:=1;--ok!
  end if;
END;