MySQL語句在select語句中的子查詢

我需要使用子查詢命名查詢中的列。我寫了一個聲明，在該SELECT部分子查詢，但我收到以下錯誤消息（來自笨返回）：MySQL語句在select語句中的子查詢

錯誤編號：1064

您的SQL語法錯誤;檢查對應於你的MySQL服務器版本使用附近的正確語法手冊 '（SELECT ps_url_name FROM product_selects WHERE ps_id = '1'），psc_opt_2 A' 位於第1行

SELECT 
    `psc_opt_1` AS (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '1'), 
    `psc_opt_2` AS (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '2'), 
    `psc_opt_3` AS (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '3'), 
    `psc_opt_4` AS (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '4'), 
    `psc_opt_5` AS (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '5') 
FROM (`product_stock_control`) 
WHERE `psc_prod_id` = '5'

文件名：車型/ products_model.php

行號：602

任何想法是什麼問題呢？

來源

2012-08-09 Phil Young

有PHP的功能，讓你從一個表中提取列名....你有沒有檢查出來？它看起來像你在一些PHP代碼中執行這個 – CheeseConQueso 2012-08-09 16:58:58

AS是列別名運算符，這意味着您選擇這些變量作爲標識符。您不能使用操作員通過查詢識別變量。

參考：http://dev.mysql.com/doc/refman/5.0/en/problems-with-alias.html

相反，你需要扭轉你如何使用別名操作符，像這樣：

SELECT 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '1') AS `psc_opt_1`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '2') AS `psc_opt_2`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '3') AS `psc_opt_3`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '4') AS `psc_opt_4`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '5') AS `psc_opt_5` 
FROM (`product_stock_control`) 
WHERE `psc_prod_id` = '5'

理想情況下，你應該避免使用子查詢（尤其是在這種情況下）以避免表鎖定開銷。

來源

2012-08-09 16:57:18

正確格式爲

(SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '1') As `psc_opt_1`

來源

2012-08-09 16:58:20

你試試這個：

SELECT 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '1') as `psc_opt_1`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '2') as `psc_opt_2`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '3') as `psc_opt_3`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '4') as `psc_opt_4`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '5') as `psc_opt_5` 
FROM (`product_stock_control`) 
WHERE `psc_prod_id` = '5'

來源

2012-08-09 16:59:01 Taryn

你想命名此列psc_opt_1到psc_opt_1或什麼什麼，你到底要什麼？

命名會是這樣的：

SELECT 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '1') AS `psc_opt_1`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '2') AS `psc_opt_2`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '3') AS `psc_opt_3`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '4') AS `psc_opt_4`, 
    (SELECT `ps_url_name` FROM `product_selects` WHERE `ps_id` = '5') AS `psc_opt_5` 
FROM (`product_stock_control`) 
WHERE `psc_prod_id` = '5'

來源

2012-08-09 17:03:08 landi

MySQL語句在select語句中的子查詢

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