user@comp:~$sqlite3  
sqlite version 3.8.2 2013-12-06 14:53:30  
Enter ".help" for instructions  
Enter sql statements terminated with a ";"  
sqlite> CREATE TABLE A (a int,b text,c float);  
sqlite> INSERT INTO A(a,b,c) VALUES (1,'2',3);  
sqlite> SELECT b::int+2 FROM A;

除了最后一行之外,所有行都有效,它给出了错误：`

Error: unrecognized token: “:”`

我正在阅读这个问题(Double colon (::) notation in SQL),双冒号表示法是sql的类型转换.我做错了吗？