Oracle Single-line function base application

single-line function

Whole the essence of SQL:Select statement + single-line function (back)

String Functions

The usual functions for working with strings are as follows :

No.	Name of function	Meaning
1	UPPER (C1) UPPER	To capitalize all strings
2	LOWER (C1) LOWER	Convert all strings to lowercase
3	Initcap (C1) Initcap	Capitalize the first letter of a string
4	LENGTHC (c1) length	Returns the length of a string
5	SUBSTR (C1,n1[,n2]) SUBSTR	Gets the substring of the string,N1 is the specified starting index,n2 is the specified number of numbers, and if n2is not written, the last one istaken.
6	Replace (C1,C2) Replace	String substitution,C1 is the old sub-character,C2 is the new substring

topic 1: Convert the string "WelcomeTozibo" to uppercase.

Select Upper (' Welcometozibo ') from dual

Topic 2: convert all employee names in the EMP table to lowercase.

Select Lower (ename) from EMP

Topic 3: The employee's name is entered by the user, and all information about the employee is displayed.

SELECT * from emp where ename= (' &input ')

can also be combined with upper using the SELECT * from emp where ename=upper (' &input ')

Topic 4: Query the emp table for all employee names and return the initials capitalized.

Select Initcap (ename) from EMP,

Topic 5: Query employee number, employee name, and position for all employees with employee name length 5.

Select Ename,job,empno from emp
where length (ename) = ' 5 '

Substr ( string, the index of the character search character to search for (you can use instr(String, the character to be searched, the number of times a character appears, and the frequency at which it occurs) is the end (Length ( characters that need to be intercepted )))

Topic 6: Get the string ' Welcometozibo ' substring ' zibo '.

Topic 7: Get the string ' Welcometozibo ' substring ' come '.

Title 8: Obtain the name of the employee of each employee of the EMP table, and the first two of the employee's name.

Substr from the back directly with '-' default starting from the last , only from the last one to which.

Title 9: Obtain the name of the employee of each employee of the EMP table, and the last two digits of the employee's name.

title : Obtain the name of the employee of each employee of the EMP table, the first two digits of the employee's name, and the last two digits as the password.

Oracle Single-line function base application