如果第一个行中没有足够的行，如何从另一个表中选择行？随着SQL

Question

我有两个表：

表 “项目”：

| id | name  | description        | 
| 1 | Michael | This is a random description blabalbla | 
| 2 | Tom  | This is another descriptions blablabla | 

表 “moreitems”：

| id | name  | description        | 
| 1 | Michael | This is a random description blabalbla | 
| 2 | Mike  | This is another descriptions blablabla | 
| 3 | Michael | This is a random description blabalbla | 
| 4 | Blain  | This is another descriptions blablabla | 

目前，我取这样从第一个表项：

SELECT * FROM items WHERE name = 'Michael' AND CHAR_LENGTH(description) > 10 LIMIT 3 

我想在查询中包含第二个表，如果限制（3）尚未达到。我怎么做 - 没有PHP？

Answer 1

尝试：

SELECT * FROM 
(SELECT 'items' table_name, i.* 
FROM items i WHERE name = 'Michael' AND CHAR_LENGTH(description) > 10 
UNION ALL 
SELECT 'moreitems' table_name, m.* 
FROM moreitems m WHERE name = 'Michael' AND CHAR_LENGTH(description) > 10 
ORDER BY 1,2) v 
LIMIT 3