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SQL数据库常用函数 SQLServer和Oracle常用函数对比

泥巴往事网  发布于:2018-08-15  分类: 心情随笔 手机版

procedure Pro_SubPro
(
dw_in in varchar2,
cur out pkg_general.ROW_CURSOR
)
as
begin
open cur for
select yqmc from fle80 where dwbm=dw_in;
end Pro_SubPro;

procedure Pro_MainPro(
dw_in in varchar2
)
as
mc NVARCHAR2(20);
cur pkg_general.ROW_CURSOR;
begin
Pro_SubPro(dw_in,cur);
fetch cur into mc;
loop
exit when cur%notfound;
dbms_output.put_line(mc);
fetch cur into mc;
end loop;
end Pro_MainPro; 数学函数
在oracle 中distinct关键字可以显示相同记录只显示一条
1.绝对值
S:select abs(-1) value
O:select abs(-1) value from dual

2.取整(大)
S:select ceiling(-1.001) value
O:select ceil(-1.001) value from dual

3.取整(小)
S:select floor(-1.001) value
O:select floor(-1.001) value from dual

4.取整(截取)
S:select cast(-1.002 as int) value
O:select trunc(-1.002) value from dual

5.四舍五入
S:select round(1.23456,4) value 1.23460
O:select round(1.23456,4) value from dual 1.2346

6.e为底的幂
S:select Exp(1) value 2.7182818284590451
O:select Exp(1) value from dual 2.71828182

7.取e为底的对数
S:select log(2.7182818284590451) value 1
O:select ln(2.7182818284590451) value from dual; 1

8.取10为底对数
S:select log10(10) value 1
O:select log(10,10) value from dual; 1

9.取平方
S:select SQUARE(4) value 16
O:select power(4,2) value from dual 16

10.取平方根
S:select SQRT(4) value 2
O:select SQRT(4) value from dual 2

11.求任意数为底的幂
S:select power(3,4) value 81
O:select power(3,4) value from dual 81

12.取随机数
S:select rand() value
O:select sys.dbms_random.value(0,1) value from dual;

13.取符号
S:select sign(-8) value -1
O:select sign(-8) value from dual -1

14.圆周率
S:SELECT PI() value 3.1415926535897931
O:不知道

15.sin,cos,tan 参数都以弧度为单位
例如:select sin(PI()/2) value 得到1(SQLServer)

16.Asin,Acos,Atan,Atan2 返回弧度

17.弧度角度互换(SQLServer,Oracle不知道)
DEGREES:弧度-〉角度
RADIANS:角度-〉弧度

数值间比较

18. 求集合最大值
S:select max(value) value from
(select 1 value
union
select -2 value
union
select 4 value
union
select 3 value)a

O:select greatest(1,-2,4,3) value from dual

19. 求集合最小值
S:select min(value) value from
(select 1 value
union
select -2 value
union
select 4 value
union
select 3 value)a

O:select least(1,-2,4,3) value from dual

20.如何处理null值(F2中的null以10代替)
S:select F1,IsNull(F2,10) value from Tbl
O:select F1,nvl(F2,10) value from Tbl

21.求字符序号
S:select ascii("a") value
O:select ascii("a") value from dual

22.从序号求字符
S:select char(97) value
O:select chr(97) value from dual

23.连接
S:select "11"+"22"+"33" value
O:select CONCAT("11","22") 33 value from dual

23.子串位置 --返回3
S:select CHARINDEX("s","sdsq",2) value
O:select INSTR("sdsq","s",2) value from dual

23.模糊子串的位置 --返回2,参数去掉中间%则返回7
S:select patindex("%d%q%","sdsfasdqe") value
O:oracle没发现,但是instr可以通过第四个参数控制出现次数
select INSTR("sdsfasdqe","sd",1,2) value from dual 返回6

24.求子串
S:select substring("abcd",2,2) value
O:select substr("abcd",2,2) value from dual

25.子串代替 返回aijklmnef
S:SELECT STUFF("abcdef", 2, 3, "ijklmn") value
O:SELECT Replace("abcdef", "bcd", "ijklmn") value from dual

26.子串全部替换
S:没发现
O:select Translate("fasdbfasegas","fa","我" ) value from dual

27.长度
S:len,datalength
O:length
28.大小写转换 lower,upper

29.单词首字母大写
S:没发现
O:select INITCAP("abcd dsaf df") value from dual

30.左补空格(LPAD的第一个参数为空格则同space函数)
S:select space(10)+"abcd" value
O:select LPAD("abcd",14) value from dual

31.右补空格(RPAD的第一个参数为空格则同space函数)
S:select "abcd"+space(10) value
O:select RPAD("abcd",14) value from dual

32.删除空格
S:ltrim,rtrim
O:ltrim,rtrim,trim

33. 重复字符串

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SQL数据库常用函数 SQLServer和Oracle常用函数对比