下划线也与大多数其他SQL数据库中的相同，并匹配任何单个字符(即，它与正则表达式中的.相同).从fine manual人中:
LIKE模式中的下划线("")匹配字符串中的任何单个字符.
例如:
-- The '_' matches the single 'c'
sqlite> select 'pancakes' like 'pan_akes';
1
-- This would need '__' to match the 'ca', only one '_' fails.
sqlite> select 'pancakes' like 'pan_kes';
0
-- '___' also fails, one too many '_'.
sqlite> select 'pancakes' like 'pan___kes';
0
为了确保结果有意义:SQLite使用zero and one for booleans.