An underscore (“_”) in the LIKE pattern matches any single character in the string.

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

只是为了确保结果有意义：sqlite使用zero and one for booleans。