Question

How can I generate the strings 'a' through 'zzz' and then save them to a table using MySQL?

Answer 1

This is a bit difficult to do from “pure” MySQL for two reasons:

• No support for recursive queries, forcing you to use temporary table to generate all possible variations.
• However, a temporary table can’t be referenced multiple times from the same query, so you can’t use a Cartesian product (i.e. CROSS JOIN) on it to generate the variations. This forces you to use the “real” table instead of the temporary.

In light of all that, the solution would look like this:

CREATE TABLE TEMP_CHARS (
    C CHAR PRIMARY KEY
);

INSERT INTO TEMP_CHARS VALUES('a'), ('b'), ('c'), ('d'), ('e'), ('f'), ('g'), ('h'), ('i'), ('j'), ('k'), ('l'), ('m'), ('n'), ('o'), ('p'), ('q'), ('r'), ('s'), ('t'), ('u'), ('v'), ('w'), ('x'), ('y'), ('z');

INSERT INTO YOUR_TABLE(YOUR_FIELD)
SELECT C
FROM TEMP_CHARS
UNION ALL
SELECT CONCAT(T1.C, T2.C) -- Generate all variations (with repetition) of length 2.
FROM TEMP_CHARS T1 CROSS JOIN TEMP_CHARS T2
UNION ALL
SELECT CONCAT(T1.C, T2.C, T3.C) -- Generate all variations (with repetition) of length 3.
FROM TEMP_CHARS T1 CROSS JOIN TEMP_CHARS T2 CROSS JOIN TEMP_CHARS T3;

DROP TABLE TEMP_CHARS;