我试图使用聚结,不具备任何行如果没有行,则返回“输入文本”。 (排序规则的非法混合)
那些进入我得到这个工作
SELECT
COALESCE(t1.it, d.it_norow)
FROM (SELECT 0 as it_norow
FROM DUAL) as d
LEFT JOIN
(SELECT t1.itemText as it
FROM bullet_items as t1
WHERE t1.cst_name = 'Cust'
AND t1.bullet_id = 'BD1') as t1
ON 1 = 1
但是,当我改变了“0”双表
SELECT
COALESCE(t1.it, d.it_norow)
FROM (SELECT 'Enter text' as it_norow
FROM DUAL) as d
LEFT JOIN
(SELECT t1.itemText as it
FROM bullet_items as t1
WHERE t1.cst_name = 'Cust'
AND t1.bullet_id = 'BD1') as t1
ON 1 = 1
我得到的错误Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation 'coalesce'
我怎样才能使“输入文字”工作时,有没有行?
你能重现问题通过提供[*'Fiddle Demo' *](http://sqlfiddle.com/)? – 2014-08-29 18:50:18