SQL statement character function, numeric function

1 --character Functions2 3 --ASCII (x) returns the ASCII code of the character x4 Select ASCII('a') fromDUAL;--back to5 6 --CONCAT (x, y) connection string X and Y7 SelectConcat'123','456') fromDual--back to 123 4568 9 --INSTR (x,str [, start][,n): Find str in X, you can specify starting from start, or you can specify starting at nth timeTen SelectInStr'HAHDF','F') fromDual--returns the location of Str One  A --Length (x) returns the lengths of X - SelectLength'd545') fromDual--returns 4 -  the --Lower (x) turns x to lowercase - Select Lower('ABCD') fromDual--back to ABCD -  - --Upper (x) turn x to uppercase + Select Upper('ABCDE') fromDual--back to ABCDE -  + --LTrim (X,[STR]) truncate the left edge of X to the STR string, and the default is to truncate the space A SELECT LTrim('===hello===','=') fromDUAL--back to hello=== at  -  - --RTrim (X,[str]) to the right of X to intercept the STR string, the default truncation of space - SELECT RTrim('===hello===','=') fromDUAL--back to ===hello -  - --trim ([str from] x) truncates the STR string on both sides of X, and truncates the space by default in SELECTTRIM ('='  from '===hello===') fromDUAL;--return HELLO -  to --Replace (x,old,new) finds an old in X and replaces it with the new + Select Replace('Avaddfs','D','e') fromDual--return result Avaeefs -  the --substr (X,start,[,length]) returns the string of X, starting at start, * --intercept length characters, default length, defaults to end $ SelectSubstr'ABCDEFG',2,4) fromDual--return: BCDEPanax Notoginseng  -  the --Mathematical Functions + --ABS (x) x absolute A Select ABS(-5) fromDual--returns 5 the  + --Inverse cosine of ACOs (x) x - Select ACOs(1) fromDual--returns 0 $  $ --cos (x) cosine - Select Cos(1) fromDual--back to 0.54030230586814 -  the --ceil (x) is greater than or equal to the minimum value of x - SelectCeil (5.2) fromDual--returns 6Wuyi  the --Floor (x) is less than or equal to the maximum value of x - Select  Floor(5.2) fromDual--returns 5 Wu  -  About --log (x, y) x is the logarithm of the low y $ Select Log(2,2) fromDual--returns 1 -  - --mod (x, y) x divided by the remainder of Y - SelectMoD2,3) fromDual--returns 2 A  + --Power (x, y) x power the Select Power(2,3) fromDual--returns 8 -  $ --round (X[,y]) x rounding in the Y position the --y defaults to 0, if Y is negative, 0 is truncated to the right of the decimal point, and if Y is positive, the decimal point is cut to the left. the Select round(2.2160,2) fromDual--Back to 2.22 the  the --the square root of sqrt (x) x - Select sqrt(4) fromDual--returns 2 in  the --trunc (X[,y]) x is truncated in the Y-bit, not rounded.  the --y defaults to 0, if Y is negative, 0 is truncated to the right of the decimal point, and if Y is positive, the decimal point is cut to the left. About SelectTrunc334.255,-1) fromDual--return to

SQL statement character function, numeric function