sqlite查询的字段拼接成字符串

使用此函数 group_concat(x[,y])

该函数返回一个字符串，该字符串将会连接所有非NULL的x值。该函数的y参数将作为每个x值之间的分隔符，如果在调用时忽略该参数，在连接时将使用缺省分隔符","。再有就是各个字符串之间的连接顺序是不确定的。

以上sql,返回表table_quality中所有diaryID相同的书中，name字段的拼接值，值之间以' '， 空格分割。

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

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