substr函数在oracle中的定义,oracle中substr函数的用法
In oracle/PLSQL, the substr functions allows you to extract a substring from a string.
The syntax for the substr function is:
substr( string, start_position, [ length ] )
说明：
string is the source string.
start_position is the position for extraction. The first position in the string is always 1.
length is optional. It is the number of characters to extract. If this parameter is omitted, substr will return the entire string.
For example:
substr(This is a test, 6, 2) would return is
substr(This is a test, 6) would return is a test
substr(TechOnTheNet, 1, 4) would return Tech
substr(TechOnTheNet, -3, 3) would return Net
substr(TechOnTheNet, -6, 3) would return The
substr(TechOnTheNet, -8, 2) would return On
In oracle/PLSQL, the substr functions allows you to extract a substring from a string. The syntax for the substr function is: substr( string, start_position, [ length ] ) 说明： string is the source string. start_position is the position for extraction. The first position in the string is always 1. length is optional. It is the number of characters to extract. If this parameter is omitted, substr will return the entire string. For example: substr(This is a test, 6, 2) would return is substr(This is a test, 6) would return is a test substr(TechOnTheNet, 1, 4) would return Tech substr(TechOnTheNet, -3, 3) would return Net substr(TechOnTheNet, -6, 3) would return The substr(TechOnTheNet, -8, 2) would return On