SQLite 将字符串拼接
SQLite中不是使用的‘+’来操作,是需要使用特殊符号“||”
例如:如果是其他字段形式的需要先装换为 字符型
使用CAST(字段名 as TEXT)
select CAST(column as TEXT) || '%' from table
用'||'拼接字符串
比如column是100的话 那结果就是100%
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