Question

我在MySQL中使用带有'order by'条件子句的预准备语句。用'？'并且变量不能用于订购之类的东西，所以我决定以其他方式制作它。我设置条件，但它是更多的代码。也许还有其他选择来减少代码并只是改变'order by'参数？

IF sorting_column_index = 1 and sorting_column_mode = 0
        THEN PREPARE STMT FROM 'SELECT a.oid as \'oid\', 
        ...

        FROM table as a

        ...
        order by numero_annee desc LIMIT ?, ?';
        EXECUTE STMT USING @skip, @ROWS;
END IF;

IF sorting_column_index = 2 and sorting_column_mode = 1
        THEN PREPARE STMT FROM 'SELECT a.oid as \'oid\', 
        ...

        FROM table as a

        ...
        order by numero_ordre asc LIMIT ?, ?';
        EXECUTE STMT USING @skip, @ROWS;
END IF;
...

Answer 1

尝试这样的事情，不使用asc / desc的参数，而是构建查询字符串：

SET @sort_order = 'desc';
SET @my_limit = 5;
SET @sql = CONCAT('SELECT whatever FROM whatever ORDER BY col1 ', @sort_order, ' LIMIT ?;');
PREPARE stmt FROM @sql;
EXECUTE stmt USING @my_limit;
DEALLOCATE PREPARE stmt;

MySQL使用order by子句编写语句

1 个答案: