Oracle | | Follow (+) + substr function Usage Summary

Oracle | | and (+) + substr function Usage Summary

"Substr function Usage"

SUBSTR (string, intercept start position, intercept length)//return intercepted word

substr (' Hello World ', 0, 1)//return result is ' H ' * start with a string of length 1 from the first character

substr (' Hello World ', 1, 1)//Returns the result for ' H ' *0 and 1 is the first character that represents the start position of the Intercept

substr (' Hello world ', 2,4)//return result as ' Ello '

substr (' Hello world ', -3,3)//Returns the result as ' rld ' * negative (-i) to indicate the start of the intercept is the left number I character of the right end of the string

Example: Select substr (' Hello world ', -3,3) value from dual;

"| | Usage

String connectors such as: ' AAA ' | | ' bbb '  = ' aaabbb '

Select ' AAA ' | | ' BBB ' from dual;

"(+) Usage"

Example:

Select  t.a from table1 t 1,table2 t2where     

1.name (+) = T2.name means to use the T2 table T1 table to do a secondary table to do the left association will use all the data t2, if and T1 is not associated with the emptying value

Oracle | | Follow (+) + substr function Usage Summary