我多次运行以下查询：
insert ignore into temp_table (ID, Price, Stock, Vendor)
select ID, Price_Vendor_A, Stock_Vendor_A, 'Vendor_A' from temp_table2 limit 1;
insert ignore into temp_table (ID, Price, Stock, Vendor)
select ID, Price_Vendor_B, Stock_Vendor_B, 'Vendor_B' from temp_table2 limit 1;
2个选择查询将指向同一行。
有更快的方法吗？
答案 0 :(得分：0)
我不知道这会更快，但您可以尝试插入一个select *
from table1 a
LEFT OUTER JOIN
(
select *
from table99
where col = 1
)b
ON (a.col1 = b.col1)
WHERE a.col2 = b.col2 AND SIGN(a.col3) = 1
LEFT OUTER JOIN
(
select *
from table99
where col = 2
)c
ON (a.col1 = c.col1)
WHERE a.col2 = c.col2 AND SIGN(a.col3) = 1;
查询：
UNION答案 1 :(得分：0)
以下将是最快的方式。消除多个选择。
SELECT ID, Price_Vendor_A, Stock_Vendor_A,Price_Vendor_B, Stock_Vendor_B into @ID, @Price_Vendor_A,@Stock_Vendor_A,@Price_Vendor_B,@Stock_Vendor_B FROM temp_table2 LIMIT 1;
insert ignore into temp_table (ID, Price, Stock, Vendor) SELECT @ID as ID, @Price_Vendor_A as price, @Stock_Vendor_A as stock ,"Vendor_A" AS Vendor UNION ALL SELECT @ID as ID, @Price_Vendor_B as price, @Stock_Vendor_B as stock ,"Vendor_B" AS Vendor