sqlite – 类型转换问题

在以下查询中,1/2的答案始终为零,而应为0.5.你能告诉我如何将两个int列转换为float / double吗？

SELECT 1/2,total,sb_ondate,likes
  FROM (
      SELECT sb_ondate,COUNT(*) AS total,STrftIME("%w",sb_ondate) AS weekDay,COUNT(CASE WHEN sb_reaction = 'like' THEN sb_id END) AS likes
        FROM diet
    GROUP BY weekDay) AS f;

谢谢.

将两个除数中的一个作为一个实数：

SELECT 1 / CAST(2 AS REAL),...

示例交互式Python会话：

>>> import sqlite3
>>> c = sqlite3.connect(':memory:')
>>> c.execute("create table t (a int,b int);")
<sqlite3.Cursor object at 0x7f9b0e9539d0>
>>> c.execute("insert into t values (1,2)")
<sqlite3.Cursor object at 0x7f9b0e953ad8>
>>> conn.execute("select a / cast(b as real) from t").fetchone()
(0.5,)

原文地址：https://www.jb51.cc/sqlite/197728.html