Substr and substring function usage in SQL

sql in substr And substring The usage function

Their functions are similar , Can intercept strings

Grammar introduction 1 ：

SUBSTR(str,pos)  amount to  SUBSTR(str FROM pos) 

SUBSTRING(str,pos) amount to SUBSTRING(str FROM pos)

Parameter Introduction

str： The string to be intercepted

pos： The starting position is the number of characters you want to intercept

Be careful :

• The character count of the string is from 1 At the beginning , No 0, If pos Write the value as 0, Will return an empty
• The starting position can be negative , Negative numbers are reciprocal , The last character is -1
• The value returned is from pos Start to finish Substring of

Case study

substr:

substring:

Grammar introduction II ：

SUBSTR(str,pos,len) amount to SUBSTR(str FROM pos FOR len)

SUBSTRING(str,pos,len) amount to SUBSTRING(str FROM pos FOR len)

Parameter Introduction

str： The string to be intercepted

pos： The starting position is the number of characters you want to intercept （ The points of attention are the same as above ）

len： The length of characters you want to intercept （ Be careful ： If this len<1, The result will return null ）

result ： Return from pos Start , The length is len Substring of

Case study

substr

substring