使用UNIONS的MySQL / MySQLi SELECT没有NULLS和ORDERED BY如何？

Question

我有这个......

$query = "SELECT {$selections} FROM {$table_1} 
        UNION ALL SELECT {$selections} FROM {$table_2} 
        UNION SELECT {$selections} FROM {$table_3}
        UNION SELECT {$selections} FROM {$table_4}
        ORDER BY FIELD(series, {$seriesOrder}) ";

这很好用，但我现在要做的是排除{$ column_7}中每个表都有NULL值的值，我试过了....

$query = "SELECT {$selections} FROM {$table_1} WHERE {$column_7} IS NOT NULL
        UNION ALL SELECT {$selections} FROM {$table_2} WHERE {$column_7} IS NOT NULL
        UNION SELECT {$selections} FROM {$table_3} WHERE {$column_7} IS NOT NULL
        UNION SELECT {$selections} FROM {$table_4} WHERE {$column_7} IS NOT NULL
        ORDER BY FIELD(series, {$seriesOrder})";

然而，这不起作用！ 我显然遗漏了一些东西，一直在研究这个问题，找不到答案需要帮助，请...

Answer 1

这是通过纠正标点符号/语法错误来解决的，这是一个缺少撇号的错误！ 哇！！ ： - ）