Hur kan jag fråga mellan två datum med "datum"-fältet är en sträng?

SELECT * FROM `table` 
WHERE str_to_date(date_field, '%d-%m-%Y') BETWEEN '2010-01-30' AND '2010-09-29'

SQLFiddle-exempel

Redigera

Du kan också göra detta:

SELECT * FROM `table` 
WHERE cast(substring(date_field, 7, 4) as unsigned) * 10000 + cast(substring(date_field, 4, 2) as unsigned) * 100 + cast(substring(date_field', 1, 2) as unsigned)
BETWEEN 20100130 AND 20100929