Exploratory Data Analysis in SQL
Christina Maimone
Data Scientist
SELECT left('abcde', 2), -- first 2 characters
right('abcde', 2); -- last 2 characters
left | right
------+-------
ab | de
SELECT left('abc', 10),
length(left('abc', 10));
left | length
------+--------
abc | 3
SELECT substring(string FROM start FOR length);
SELECT substring('abcdef' FROM 2 FOR 3);
bcd
SELECT substr('abcdef', 2, 3);
some text,more text,still more text
^ ^
delimiter delimiter
Fields/chunks:
SELECT split_part(string, delimiter, part);
SELECT split_part('a,bc,d', ',', 2);
bc
SELECT split_part('cats and dogs and fish', ' and ', 1);
cats
SELECT concat('a', 2, 'cc');
a2cc
SELECT 'a' || 2 || 'cc';
a2cc
SELECT concat('a', NULL, 'cc');
acc
SELECT 'a' || NULL || 'cc';
Exploratory Data Analysis in SQL