On PHP 5.3.13/MySQL 5.5.21 the following code doesn\'t work:
if($check_custom_fields_form!=1){
$sql = "CREATE TABLE IF NOT EXISTS ". $table_custom_fields_form ." (
`form_name` longtext NOT NULL,
`field_id` bigint(20) NOT NULL,
FOREIGN KEY (`field_id`) REFERENCES $table_custom_fields (`ID`) ON DELETE CASCADE ON UPDATE CASCADE
) CHARACTER SET utf8 COLLATE utf8_general_ci";
dbDelta($sql);
}
if($check_subscribe_cat!=1){
$sql = "CREATE TABLE IF NOT EXISTS ". $table_subscribe_cat ." (
`subscribe_id` bigint(20) NOT NULL,
`cat_id` bigint(20) NOT NULL,
FOREIGN KEY (`subscribe_id`) REFERENCES ".$wpdb->prefix."tgt_subscription (`ID`) ON DELETE CASCADE ON UPDATE CASCADE,
FOREIGN KEY (`cat_id`) REFERENCES ".$wpdb->prefix."terms (`term_id`) ON DELETE CASCADE ON UPDATE CASCADE
) CHARACTER SET utf8 COLLATE utf8_general_ci";
dbDelta($sql);
}
The code provider suggested a downgrade to MySQL 5.1.37 (no, thanks) or the following update:
if($check_custom_fields_form!=1){
$sql = "CREATE TABLE IF NOT EXISTS ". $table_custom_fields_form ." (
`form_name` longtext NOT NULL,
`field_id` bigint(20) NOT NULL,
KEY(field_id)
) CHARACTER SET utf8 COLLATE utf8_general_ci";
dbDelta($sql);
}
if($check_subscribe_cat!=1){
$sql = "CREATE TABLE IF NOT EXISTS ". $table_subscribe_cat ." (
`subscribe_id` bigint(20) NOT NULL,
`cat_id` bigint(20) NOT NULL,
KEY(subscribe_id),
KEY(cat_id)
) CHARACTER SET utf8 COLLATE utf8_general_ci";
dbDelta($sql);
}
这似乎是解决问题的一种相当肮脏的方式（没有级联删除/更新）。因此：
- Do I really have to live with that until dbDelta supports FOREIGN
KEY?
- Is it true that dbDelta only works with foreign key in a 3 year old MySQL version?
最合适的回答,由SO网友:TheDeadMedic 整理而成
在dbDelta支持外键之前，我真的必须接受这种情况吗？
坦白说，是的。但这就是开源的美妙之处——欢迎任何人发布补丁！
However, 将其扩展到模式设计的其他方面几乎肯定会带来不必要的复杂性；提高失败的可能性——这是核心团队事先会强烈考虑的。
我会接受@xav0989的建议-使用dbDelta 根据其意图（基本表实现、列添加和调整），并使用$wpdb.
