How to emulate REPEAT() in SQLite

问题

Most relational databases have some sort of REPEAT() string function, for instance:

SELECT REPEAT('abc', 3)

Would yield

abcabcabc

SQLite on the other hand has a very limited feature set. The functions supported by SQLite are listed here:

http://www.sqlite.org/lang_corefunc.html

Can REPEAT() be emulated with the functions available in SQLite?

回答1:

A simplified version of @Lukas Eder's solution using hex() instead of quote:

-- X = string
-- Y = number of repetitions

replace(hex(zeroblob(Y)), '00', X) 

回答2:

A solution was inspired by this answer to a related question, here:

How to simulate LPAD/RPAD with SQLite

I wanted to share this on Stack Overflow, as this may be useful to other SQLite users. The solution goes like this:

-- X = string
-- Y = number of repetitions

replace(substr(quote(zeroblob((Y + 1) / 2)), 3, Y), '0', X)

回答3:

If its a single character you want to repeat, you can use printf function.

Bellow is an example where * is repeated 10 times.

sqlite> select printf('%.' || 10 ||'c', '*');
**********

To repeat multiple characters please see Lukas's answer above.

来源：https://stackoverflow.com/questions/11568496/how-to-emulate-repeat-in-sqlite