built in functions

String functionsSelect concat (' Hello ', ' word ', ' my ')  myname; // concat ()    link character functions    output  hellowordmy  myname is the alias Select lcase (' MYSQL ');                     //lcase ()     Convert to lowercase       Output  

Function Description AVG (x) The function returns the average of the same set of internal reference numbers. For string and BLOB type field values that cannot be converted to numeric values, such as ' HELLO ', SQLite treats

Three. Character functions (can be used for literal characters or database columns)1, String interceptSelect substr (' abcdef ', 1,3) from dual2, finding the substring locationSelect InStr (' Abcfdgfdhd ', ' FD ') from dual3, String connectionSelect

1,nvl2 (a,b,c) --expression 1 is not NULL, returns expression 2, or null. Returns an expression of 3. Expression 2 is different from the expression 3 type, and expression 3 is converted to the type of expression 2.2,nvl (expression 1, Expression 2)--

function return value sample displayCeil (n) the smallest integer greater than or equal to the value N, SELECT ceil (10.6) from TABLE_NAME; 11Floor (n) the largest integer less than or equal to the value N, SELECT floor (10.6) from TABLE_NAME; 10MOD

InstanceMD5 Encryption "123456":Hashbytes (' MD5 ', ' 123456 ')Result: 0xe10adc3949ba59abbe56e057f20f883e (hint: After the end, the result is converted. ）Function Function Describe return value Hashbytes

Commonly used in a total of 4 methods, as follows: 1. Using the Locate () method1.1. General Usage: SELECT ' column ' from ' Table ' where locate ('keyword', ' condition ') >0Java-like indexOf (); however locate () as long as the found returned

Numeric functions: 1, rounding function round () from dual: A row of a column composed of select round (23.4) from dual;--default not write M for M for 0select round (23.45,1) from dual;-- 1 means to keep one digit after the decimal point, then the

One. String functionsSelect concat (Name, "Age was", age) from users;   Insert (Str,x,y,insert)//Replace y position of string x position with insert  Select Lower (str) upper (str)//conversion caseSELECT * from user where upper (name) = ' AAA '; 

1.__new__ (CLS, *args, **kwargs)Called when an object is created, returning an instance of the current object; Note: The first parameter here is the CLS, the class itself2.__init__ (self, *args, **kwargs)Called after the object has been created,

Python built-in functions1.abs Absolute Value2.alldetermines whether all data in the iterator is truereturns True if all data of the data that can be iterated is true or the data that is iterated is empty. Otherwise returns false3.anydetermine if a

When I look at my blog, I choose to die.Divmod (A, b) #返回a//b values and remainders = divmod (97,10) Print (s) N1, N2 = Divmod (89,5) Print (N1,N2) Isinstance () #判断对象是否是某个类的实例 filter (function, iteration object) Li =

1. Functions1.1 Defining functions• The function code block begins with a def keyword followed by the function identifier name and parentheses ().• Any incoming parameters and arguments must be placed in the middle of the parentheses, and the

1. CSS ()---Get or set CSS propertiesKinds of Syntex:I. $ (' #foo '). CSS (' background ', ' #fff000 ', ' width ', ' 100px ');Ii. $ (' #foo '). CSS ({background: ' #fff000 ',}); Original CSS Syntex2. Text ()---Get or set the value of an element$ (' #

Common SqlServer built-in functions and usage Select cast ('2014/1/03 'as datetime ); Select convert (varchar (10), GETDATE (), 120); -- convert to date type Select case when id = 1 THEN 'a0 'else 'TT' END from demo1; -- case when Select len ('ssa

Python built-in functions Dir (_ builtins __) 1. 'abs '. Obtain the absolute value of the input parameter. abs(x, /) Return the absolute value of the argument. 1 >>> abs(10)2 103 >>> abs(-10)4 10 2. 'all' is used to determine whether all elements

Python learning diary: day15: ------ built-in functions, pythonday15 1. Scope-related 1) locals () --------- obtain the dictionary of local variables in the namespace in which the method is executed # Return all names in the local scope 2) globals ()

Python study Note 6: built-in functions and python Study NotesI. Mathematical Problems 1. Absolute Value: abs (-1) 2. maximum and minimum values: max ([1, 2, 3]), min ([1, 2, 3]) 3. Sequence length: len ('abc'), len ([1, 2, 3]), len (1, 2, 3 )) 4.

Introduction to filter map reduce in Python built-in functions, pythonreduce Python has built-in interesting and useful functions, such as filter, map, and reduce, which are used to process a set. filter is easy to understand for filtering and map

ABS (x)ABS () returns the absolute value of a number. If the plural is given, the return value is the modulus of the complex number.>>>print ABS (-100) 100>>>print ABS (1+2J) 2.2360679775Callable (object)The callable () function is used to test