Oracle Foundation (11) String functions

One, the string function

LENGTH (CHAR):

SELECT LENGTH ('abc def GH' from dual;  -- gets the length of the string that contains the space result:

CONCAT (CHAR1,CHAR2)

SELECTCONCAT ('ABC','def') fromDual--Connect two stringsResults:'abcdef'SELECT 'ABC'||'def'  fromDual--Connect two stringsResults:'abcdef'

Initcap (CHAR):　

SELECT Initcap ('hello' from dual;      -- first letter to uppercase result: Hello

LOWER (CHAR):

SELECT LOWER ('HELLOWorld' from dual;  -- convert string to lowercase result: Hello World

UPPER (CHAR):

SELECT UPPER ('helloworld' from dual;  -- convert string to uppercase result: HELLO World

LTRIM (Char,set):

SELECT LTRIM ('  Hello  World' from dual;  -- remove whitespace from the left of the string result:'hello   world'

RTRIM (Char,set):

SELECT RTRIM ('  Hello  World' from dual;  -- remove whitespace to the right of the string result:'  helloworld'

TRANSLATE (char,from,to):

SELECTTranslate ('Abcdefabcdef','ABC','123') fromDual--Replace ABC with 123 if the replacement character is contiguousResults:'123def123def'SELECTTranslate ('Abcdefabcdef','Ace','123') fromDual--if characters are not contiguous, they are replaced by lettersResults:'1b2d3f1b2d3f'

REPLACE (CHAR,SEARCH_STR,REPLACE_STR)　

SELECT REPLACE ('abcdefabcdef','abc','123'  from dual;  -- Replace the string ABC with the 123 result: 123def123def

INSTR (Char,substr[,pos])

SELECTINSTR ('Abcdefabcdef','def') fromDual--Find the Def position in the string, starting with 1Results:4SELECTINSTR ('Abcdefabcdef','def',5) fromDual--finds the DEF position in the string starting at the specified position, starting with 1The result is:Ten

SUBSTR (Char,pos,len)

SELECTSUBSTR ('ABCDEFGH',3) fromDual--intercepts the string from the 3rd bit to the endResults:'CDEFGH'SELECTSUBSTR ('ABCDEFGH',3,2) fromDual--Intercept 2 strings starting from 3rd bitResults:'CD'

Oracle Basic (11) String function