执行一次SQL查询，修改UPDATE多行记录

标签：执行一次sql查询   修改update多行记录   

通常情况下，我们会使用以下SQL语句来更新字段值：

UPDATE mytable SET myfield='value' WHERE other_field='other_value';UPDATE mytable SET myfield='value' WHERE other_field='other_value';

foreach ($display_order as $id => $ordinal) {
     $sql="UPDATE categories SET display_order = $ordinal WHERE id = $id";
     mysql_query($sql);
}

UPDATE mytable
     SET myfield = CASE other_field
         WHEN 1 THEN 'value'
         WHEN 2 THEN 'value'
         WHEN 3 THEN 'value'
     END
WHERE id IN (1,2,3)

UPDATE categories
     SET display_order = CASE id
         WHEN 1 THEN 3
         WHEN 2 THEN 1
         WHEN 3 THEN 2
     END
WHERE id IN (1,2,3)

如果你需要更新一行记录的多个字段，可以用以下SQL语句：

UPDATE categories
     SET display_order = CASE id
         WHEN 1 THEN 3
         WHEN 2 THEN 4
         WHEN 3 THEN 5
     END,
     title = CASE id
         WHEN 1 THEN 'New Title 1'
         WHEN 2 THEN 'New Title 2'
         WHEN 3 THEN 'New Title 3'
     END
WHERE id IN (1,2,3)

$display_order = array(
     1 => 4,
     2 => 1,
     3 => 2,
     4 => 3,
     5 => 9,
     6 => 5,
     7 => 8,
     8 => 9
);

$ids = implode(',', array_keys($display_order));
$sql = "UPDATE categories SET display_order = CASE id ";
foreach ($display_order as $id => $ordinal) {
     $sql .= sprintf("WHEN %d THEN %d ", $id, $ordinal);  // 拼接SQL语句
}
$sql .= "END WHERE id IN ($ids)";
echo $sql;
mysql_query($sql);

文章参考出自:http://www.jbxue.com/db/mysql_update_h4hxn37M2.html

执行一次SQL查询，修改UPDATE多行记录

标签：执行一次sql查询   修改update多行记录   

原文地址：http://blog.csdn.net/web361/article/details/42455341