MySQL interception_ MySQL method for intercepting strings [easy to understand]

Hello everyone , I meet you again , I'm your friend, Quan Jun .

1、 Intercept the string from the left

left(str, length)

explain ：left( Intercepted field , Interception length )

example ：select left(content,200) as abstract from my_content_t

2、 Intercept the string from the right

right(str, length)

explain ：right( Intercepted field , Interception length )

example ：select right(content,200) as abstract from my_content_t

3、 Intercepting string

substring(str, pos)

substring(str, pos, length)

explain ：substring( Intercepted field , Starting from the first few )

substring( Intercepted field , Starting from the first few , Interception length )

example ：select substring(content,5) as abstract from my_content_t

select substring(content,5,200) as abstract from my_content_t

( notes ： If the number of digits is negative Such as -5 It's the last digit , The length to the end of a string or the length to be intercepted )

4、 Intercept string by keyword

substring_index(str,delim,count)

explain ：substring_index( Intercepted field , keyword , The number of times keywords appear )

example ：select substring_index(”blog.chinabyte.com”,”.”,2) as abstract from my_content_t

result ：blog.chinabyte

( notes ： If the number of times a keyword appears is negative Such as -2 It's counting backwards , To the end of the string )

result ：chinabyte.com

The intercepted string is 15,151,152,16’, It can be seen as ip Well ( Although this does not mean iP),

Then I'm going to intercept the part before each comma

Publisher ： Full stack programmer stack length , Reprint please indicate the source ：https://javaforall.cn/131770.html Link to the original text ：https://javaforall.cn