向Wordpress数据库添加新列 [英] Add new column to wordpress database

问题描述

我尝试更新插件.因此，我必须升级mysql_table.但是，当尝试新列时，程序会获得异常.

I trying update my plugin. So I must upgrade mysql_table. But when trying new column, program get exception.

这是我当前的表格:

$sql = "CREATE TABLE  {$table_name} (
        say_id             int(11)   not null AUTO_INCREMENT,
        customer_mail      text      not null,
        customer_name  text      not null,
        customer_messagge      text      not null,
        messagge_date_time  datetime  not null,

        PRIMARY KEY (say_id)
        )ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1";

        require_once(ABSPATH . "wp-admin/includes/upgrade.php");
        dbDelta($sql);

现在我将向colum添加更多一张桌子.我尝试使用Alter表，这种方法可以工作一次并添加一列，但是再刷新一次，我会收到此错误.

Now I am add colum more one table. I try Alter table, this working one time and add a column but one more refresh I get this error.

这是我的代码

$wpdb->query("ALTER TABLE wp_customer_say ADD say_state INT(1) NOT NULL DEFAULT 1");

这是我的错误

WordPress数据库错误:[重复的列名'say_state'] ALTER TABLE wp_customer_say ADD say_state INT(1)NOT NULL DEFAULT 1

WordPress database error: [Duplicate column name 'say_state'] ALTER TABLE wp_customer_say ADD say_state INT(1) NOT NULL DEFAULT 1

我看到此错误，然后尝试尝试；

I see this error and ı try this;

$query          = $wpdb->query("select * from wp_customer_say");
        $respond        = mysql_num_fields( $query );
        $column_array   = array();

        for($i = 0; $i < $respond ; $i++):
            $column_array[]     = mysql_field_name($query,$i);
        endfor;

        if( !in_array("say_state",$column_array) ):
            $wpdb->query("ALTER TABLE wp_customer_say ADD say_state INT(1) NOT NULL DEFAULT 1");
        endif;

我得到这个错误.

Warning: mysql_num_fields() expects parameter 1 to be resource, integer given in

请帮助.谢谢你. 对不起，英语不好.

Help please. Thank you. Sorry bad english.

推荐答案

使用此查询.我只使用mysql-standred来通过快速查询获取字段名称，这将解决您的问题:

Use this query. I use only mysql-standred for get field name by fast query and this will solve your problem:

$row = $wpdb->get_results(  "SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'wp_customer_say' AND column_name = 'say_state'"  );

if(empty($row)){
   $wpdb->query("ALTER TABLE wp_customer_say ADD say_state INT(1) NOT NULL DEFAULT 1");
}

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