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| Mysql计厩ㄧ计ぃ― |
| セゅ:http://linuxdb.yeah.net : (2001-07-05 16:10:00) |
┮Τ计厩ㄧ计岿薄猵NULL
-
虫ヘ搭э跑把计才腹
mysql> select - 2;
猔種狦硂巨才籔BIGINTㄏノ琌BIGINT硂種帝莱赣磷俱计ㄏノ-êΤ-2^63
ABS(X)
X荡癸
mysql> select ABS(2);
-> 2
mysql> select ABS(-32);
-> 32
赣ノBIGINT
SIGN(X)
把计才腹-10┪1∕X琌琌璽计箂┪タ计
mysql> select SIGN(-32);
-> -1
mysql> select SIGN(0);
-> 0
mysql> select SIGN(234);
-> 1
MOD(N,M)
%
家 (摸Cい%巨才)N砆M埃计
mysql> select MOD(234, 10);
-> 4
mysql> select 253 % 7;
-> 1
mysql> select MOD(29,9);
-> 2
硂ㄧ计ノBIGINT
FLOOR(X)
ぃX程俱计
mysql> select FLOOR(1.23);
-> 1
mysql> select FLOOR(-1.23);
-> -2
猔種砆跑传BIGINT
CEILING(X)
ぃX程俱计
mysql> select CEILING(1.23);
-> 2
mysql> select CEILING(-1.23);
-> -1
猔種砆跑传BIGINT
ROUND(X)
把计Xき俱计
mysql> select ROUND(-1.23);
-> -1
mysql> select ROUND(-1.58);
-> -2
mysql> select ROUND(1.58);
-> 2
猔種砆跑传BIGINT!
ROUND(X,D)
把计XきΤD计计狦D0挡狦盢⊿Τ计翴┪计场だ
mysql> select ROUND(1.298, 1);
-> 1.3
mysql> select ROUND(1.298, 0);
-> 1
猔種砆跑传BIGINT!
EXP(X)
e礛癸计┏XΩよ
mysql> select EXP(2);
-> 7.389056
mysql> select EXP(-2);
-> 0.135335
LOG(X)
X礛癸计
mysql> select LOG(2);
-> 0.693147
mysql> select LOG(-2);
-> NULL
狦稱璶计Xヴ種┏B癸计ㄏノそΑLOG(X)/LOG(B)
LOG10(X)
X10┏癸计
mysql> select LOG10(2);
-> 0.301030
mysql> select LOG10(100);
-> 2.000000
mysql> select LOG10(-100);
-> NULL
POW(X,Y)
POWER(X,Y)
XYΩ经
mysql> select POW(2,2);
-> 4.000000
mysql> select POW(2,-2);
-> 0.250000
SQRT(X)
獶璽计Xキよ
mysql> select SQRT(4);
-> 2.000000
mysql> select SQRT(20);
-> 4.472136
PI()
PI蛾㏄瞯
mysql> select PI();
-> 3.141593
COS(X)
X┒, 硂柑X┓倒
mysql> select COS(PI());
-> -1.000000
SIN(X)
Xタ┒X┓倒
mysql> select SIN(PI());
-> 0.000000
TAN(X)
XタちX┓倒
mysql> select TAN(PI()+1);
-> 1.557408
ACOS(X)
Xは┒ㄤ┒琌X狦Xぃ-11璖瞅NULL
mysql> select ACOS(1);
-> 0.000000
mysql> select ACOS(1.0001);
-> NULL
mysql> select ACOS(0);
-> 1.570796
ASIN(X)
Xはタ┒ㄤタ┒琌XL狦Xぃ-11璖瞅NULL
mysql> select ASIN(0.2);
-> 0.201358
mysql> select ASIN('foo');
-> 0.000000
ATAN(X)
Xはタちㄤタち琌X
mysql> select ATAN(2);
-> 1.107149
mysql> select ATAN(-2);
-> -1.107149
ATAN2(X,Y)
2跑秖X㎝Yはタちウ摸璸衡Y/Xはタち埃ㄢ把计才腹砆ノㄓ∕﹚挡狦禜
mysql> select ATAN(-2,2);
-> -0.785398
mysql> select ATAN(PI(),0);
-> 1.570796
COT(X)
Xち
mysql> select COT(12);
-> -1.57267341
mysql> select COT(0);
-> NULL
RAND()
RAND(N)
璖瞅01.0ず繦诀疊翴狦俱计把计N砆﹚ウ砆ノ贺
mysql> select RAND();
-> 0.5925
mysql> select RAND(20);
-> 0.1811
mysql> select RAND(20);
-> 0.1811
mysql> select RAND();
-> 0.2079
mysql> select RAND();
-> 0.7888
ぃORDER BYノRAND()ㄏノORDER BY盢確璸衡Ω礛τMySQL3.23い暗 SELECT * FROM table_name ORDER BY RAND()硂琌Τ眔ㄓSELECT * FROM table1,table2 WHERE a=b AND c
LEAST(X,Y,...)
Τ2㎝2把计程(程)把计把计ㄏノ砏玥秈︽ゑ耕
狦砆ㄏノINTEGERゅ┪┮Τ把计常琌俱计俱计ゑ耕
狦砆ㄏノREALゅ┪┮Τ把计琌龟计龟计ゑ耕
狦ヴ把计琌庇稰才﹃把计糶庇稰才﹃砆ゑ耕
ㄤ薄猵把计糶礚闽才﹃砆ゑ耕
mysql> select LEAST(2,0);
-> 0
mysql> select LEAST(34.0,3.0,5.0,767.0);
-> 3.0
mysql> select LEAST("B","A","C");
-> "A"
MySQL 3.22.5玡セㄏノMIN()τぃ琌LEAST
GREATEST(X,Y,...)
程(程)把计把计ㄏノ籔LEAST妓砏玥秈︽ゑ耕
mysql> select GREATEST(2,0);
-> 2
mysql> select GREATEST(34.0,3.0,5.0,767.0);
-> 767.0
mysql> select GREATEST("B","A","C");
-> "C"
MySQL 3.22.5 玡セ, ㄏノMAX()τぃ琌GREATEST.
DEGREES(X)
把计X眖┓跑传à
mysql> select DEGREES(PI());
-> 180.000000
RADIANS(X)
把计X眖à跑传┓
mysql> select RADIANS(90);
-> 1.570796
TRUNCATE(X,D)
计X篒耞D计狦D0挡狦盢⊿Τ计翴┪计场だ
mysql> select TRUNCATE(1.223,1);
-> 1.2
mysql> select TRUNCATE(1.999,1);
-> 1.9
mysql> select TRUNCATE(1.999,0);
-> 1
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