MySql 批量插入

replace into 批量更新

replace into test_tbl (id,dr) values (1,'2'),(2,'3'),...(x,'y');

注意：操作本质是对重复的记录先delete 后insert，如果更新的字段不全会将缺失的字段置为缺省值，用这个要悠着点否则不小心清空大量数据可不是闹着玩的

insert into …on duplicate key update批量更新

insert into test_tbl (id,dr) values (1,'2'),(2,'3'),...(x,'y') on duplicate key update dr=values(dr);

注意：id必须为主键或者唯一索引，而且没有时会插入新数据，只update重复记录，不会改变其它字段

创建临时表，先更新临时表，然后从临时表中update

create temporary table tmp(id int(4) primary key,dr varchar(50));
insert into tmp values  (0,'gone'), (1,'xx'),...(m,'yy');
update test_tbl, tmp set test_tbl.dr=tmp.dr where test_tbl.id=tmp.id;

注意：需要创建临时表的权限

使用mysql 自带的语句构建批量更新

UPDATE tableName
    SET orderId = CASE id 
        WHEN 1 THEN 3 
        WHEN 2 THEN 4 
        WHEN 3 THEN 5 
    END
WHERE id IN (1,2,3)

更新orderId 字段，如果id=1 则orderId 的值为3，如果id=2 则orderId 的值为4，where部分不影响代码的执行，但是会提高sql执行的效率

如果更新多个值的话，只需要稍加修改：

UPDATE categories 
    SET orderId = 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)

PHP Example:

$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); 
} 
$sql .= "END WHERE id IN ($ids)"; 
echo $sql;