SQL -> Funkcie -> Funkcie pre prácu s reťazcami -> SQL - substring
Syntax
SUBSTRING(str,pos)
SUBSTRING(str FROM pos)
SUBSTRING(str,pos,len)
SUBSTRING(str FROM pos FOR len)
Popis
Príkaz jazyka SQL
The forms without a len argument return a substring from string str starting at position pos. The forms with a len argument return a substring len characters long from string str, starting at position pos. The forms that use FROM are standard SQL syntax. Beginning with MySQL 4.1.0, it is possible to use a negative value for pos. In this case, the beginning of the substring is pos characters from the end of the string, rather than the beginning. A negative value may be used for pos in any of the forms of this function.
This function is multi-byte safe.
If len is less than 1, the result is the empty string.
SUBSTR is a synonym for SUBSTRING().
Príklad
SELECT SUBSTRING
('Quadratically',5
);
->
'ratically'
SELECT SUBSTRING
('foobarbar' FROM 4
);
->
'barbar'
SELECT SUBSTRING
('Quadratically',5,6
);
->
'ratica'
SELECT SUBSTRING
('Sakila', -3
);
->
'ila'
SELECT SUBSTRING
('Sakila', -5, 3
);
->
'aki'
SELECT SUBSTRING
('Sakila' FROM -4 FOR 2
);
->
'ki'