select path || '%' from t_category where depth = 0 and type = 0
用'||'拼接字符串
比如path是/1001/的话 那结果就是/1001/%
数字相加
SELECT 'A'+'B' 结果为0
SELECT "A"+"1" 结果为1
SELECT "A"+1 结果为1
SELECT 2+1 结果为3
=在“+”运算中，SQLite将字符串非数字串都当作0处理了
|| String Concatenation
* Arithmetic Multiply
/ Arithmetic Divide
% Arithmetic Modulus
+ Arithmetic Add
– Arithmetic Subtract
<< Bitwise Right shift
>> Bitwise Left shift
& Logical And
| Logical Or
< Relational Less than
<= Relational Less than or equal to
> Relational Greater than
>= Relational Greater than or equal to
= Relational Equal to
== Relational Equal to
<> Relational Not equal to
!= Relational Not equal to
IN Logical In
AND Logical And
OR Logical Or
LIKE Relational String matching
GLOB Relational Filename matching
