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What are the string functions in MySQL

Shulou Source: shulou.com Published: 2022-06-01 02:36:46 09月23日 Update

Editor to share with you what the string functions in MySQL are, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

String function

1. Returns the ASCII code of the first character of the string s

SELECT ASCII ('AB');-returns the ASCII code value of A: 65

2. LENGTH/CHAR_LENGTH (s) / CHARACTER_LENGTH (s) returns the number of characters of the string s

SELECT LENGTH ('1234');-return 4

3. CONCAT (S1 ~ S2... Sn) string s1and other strings are merged into a single string

SELECT CONCAT ('hel','llo');-return hello

4. FIND_IN_SET (S1 ~ S2) returns the position of the string that matches S1 in the string S2

SELECT FIND_IN_SET ("c", "arecrum bregory credpene");-return 3

5. The FORMAT (xQuery n) function can format the number x into "#, #. # #", keeping x to n places after the decimal point, and rounding the last digit.

SELECT FORMAT (250500.5634, 2);-returns 250500.56

6. INSERT (S1, x, rep, Len2) string S2 replaces the x position of S1, starting with a string of length len

SELECT INSERT ("google.com", 1, 6, "runnob");-returns runoob.com

7. LOCATE (S1 ~ s) gets the starting position of S1 from the string s

SELECT LOCATE ('st','myteststring');-return 5

8. LCASE (s) / LOWER (s) changes all letters of the string s to lowercase letters

SELECT LOWER ('RUNOOB');-return runoob

9. UCASE (s) / UPPER (s) changes all letters of the string s to uppercase letters

SELECT UCASE ('runoob');-return RUNOOB

10. TRIM (s) removes the spaces at the beginning and end of the string s

SELECT TRIM ('RUNOOB');-return RUNOOB

11. LTRIM (s) removes the space at the beginning of the string s

SELECT LTRIM ('RUNOOB');-return 'RUNOOB'

12. RTRIM (s) removes the space at the end of the string s

SELECT RTRIM ('RUNOOB');-return' RUNOOB'

13. SUBSTR (s, start, length) truncates a substring of length length from the start position of the string s

SELECT SUBSTR ("RUNOOB", 2,3) AS ExtractString;---- intercepts 3 characters from the second position in the string RUNOOB and returns UNO

14. SUBSTR/SUBSTRING (s, start, length) truncates a substring of length length from the start position of the string s

SELECT SUBSTR/SUBSTRING ("RUNOOB", 2,3);-truncate 3 characters from the second position in the string RUNOOB and return UNO

15. POSITION (S1 IN s) gets the starting position of S1 from the string s

SELECT POSITION ('b' in 'abc');-return 2

16. REPEAT (sQuery n) repeat the string s n times

SELECT REPEAT ('runoob',3);-return runoobrunoobrunoob

17. REVERSE (s) reverses the order of the string s

SELECT REVERSE ('abc');-return cba

18. STRCMP (S1 and S2) compare the strings S1 and S2, return 0 if S1 and S2 are equal, if S1 > S2 return 1, if S1

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