Question

我正在尝试使用LIMIT和OFFSET从数据库中检索记录，但是当我在最后添加ORDER BY id时，它会失败。

我的代码如下:(这个工作正常）

$sql6 = "SELECT * FROM products WHERE cat = 'category' LIMIT 10 OFFSET 0";
    $result6 = $conn->query($sql6);
        if ($result6->num_rows > 0) { 
        while($row6 = $result6->fetch_assoc()) { 
        echo $row6["position"];
} } else{}

添加ORDER后，它不会显示任何记录：

$sql6 = "SELECT * FROM products WHERE cat = 'category' LIMIT 10 OFFSET 0 ORDER BY id DESC";
    $result6 = $conn->query($sql6);
        if ($result6->num_rows > 0) { 
        while($row6 = $result6->fetch_assoc()) { 
        echo $row6["position"];
} } else{}

感谢任何帮助。

Answer 1

LIMIT必须在声明的末尾：

SELECT * FROM products WHERE cat = 'category'  ORDER BY id DESC LIMIT 10 OFFSET  0

来自documentation：

选择 [全部| DISTINCT | DISTINCTROW] [HIGH_PRIORITY] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS] select_expr [，select_expr ...] [FROM table_references [WHERE where_condition] [GROUP BY {col_name | expr |位置} [ASC | DESC]，... [与ROLLUP]] [HAVING where_condition] [ORDER BY {col_name | expr |位置} [ASC | DESC]，...] [LIMIT {[offset，] row_count | row_count OFFSET offset}] [PROCEDURE procedure_name（argument_list）] [INTO OUTFILE＆＃39; file_name＆＃39; [CHARACTER SET charset_name] export_options | INTO DUMPFILE＆＃39; file_name＆＃39; | INTO var_name [，var_name]] [FOR UPDATE |锁定共享模式]]

BTW：执行声明后检查错误

PHP使用带有ORDER BY标识

1 个答案: