mysql中selectsql中casewhen条件放到where条件内在mysql中的两种情况1、
INSERT INTO table_xxx(x1,x2,x3,x4)
SELECT y1,y2,y3,y4 FROM TABLE_yyy
WHERE
CASE
WHEN y5 = m5
THEN
y6 = m61
ELSE
y6 = m62
END
AND y7 = m7；
2、
INSERT INTO table_xxx(x1,x2,x3,x4)
SELECT y1,y2,y3,y4 FROM TABLE_yyy
WHERE
y6 =
CASE
WHEN y5 = m5
THEN
  m61
ELSE
  m62
END
AND y7 = m7；
期中，第⼆种情况在C#中执⾏会抛出异常说字段不匹配，在使⽤mysql_log ⼯具执⾏的时候会出现警告。