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dbDelta/SQL error, very unexpected

开发者 https://www.devze.com 2023-03-15 21:10 出处:网络
Here\'s an error that I\'m having trouble with. It occurs when I use the dbDelta function in Wordpress. I can\'t really figure it out, perhaps someone else has experience something similar? 开发者_Go百

Here's an error that I'm having trouble with. It occurs when I use the dbDelta function in Wordpress. I can't really figure it out, perhaps someone else has experience something similar? 开发者_Go百科My code:

$sql1 = "CREATE TABLE `".$table_name1."` (
`id` INT( 11 ) NOT NULL AUTO_INCREMENT  PRIMARY KEY ,
`blogid` INT( 11 ) NOT NULL ,
`symbol` VARCHAR( 255 ) NOT NULL
) ENGINE = MYISAM";

I trigger this code during the theme_switch action. And it does not seem to occur when I turn the theme on, only when I switch to something else (I know, it's weird). I have read and I have attempted to follow the caveats mentioned at Wordpress.org, for example putting two spaces between primary key and the definition. I have two other, similar, pieces of SQL code that generate the same error; all three were originally generated by phpMyAdmin so I know that they work.

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/wp-experiment/wp-admin/includes/upgrade.php on line 1463

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/wp-experiment/wp-admin/includes/upgrade.php on line 1463

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/wp-experiment/wp-admin/includes/upgrade.php on line 1463

WordPress database error: [Multiple primary key defined]
ALTER TABLE wp_stocks_0 CHANGE COLUMN id `id` INT( 11 ) NOT NULL AUTO_INCREMENT PRIMARY KEY

Warning: Cannot modify header information - headers already sent by (output started at /Applications/MAMP/htdocs/wp-experiment/wp-admin/includes/upgrade.php:1463) in /Applications/MAMP/htdocs/wp-experiment/wp-includes/pluggable.php on line 897

In case I have misunderstood dbDelta, I should perhaps add, that the above code is executed several times.. so the table already exists. But if I understand dbDelta, that means it simply ought to do nothing because there is nothing in the db structure that needs changing.


A bit late - but discovered this question when searching for a solution to the same error messages - I'm adding an answer for anyone else who discovers this:

from the codex docs http://codex.wordpress.org/Creating_Tables_with_Plugins

  • You must not use any apostrophes or backticks around field names.

That fixed it for me


My problem was that I had an extra space between 'create table' and the table name.

I had:

$sqlOptions = "CREATE TABLE  $options_table_name (

Where I needed:

$sqlOptions = "CREATE TABLE $options_table_name (

Picky function


Try --

$sql1 = "CREATE TABLE `".$table_name1."` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`blogid` int(11) NOT NULL,
`symbol` varchar(255) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MYISAM";

In my experience, dbDelta is even fussier than alluded to in the Codex.

Update
From your edit, I would suggest you first check / only create the database if it doesn't exist yet, which you can do using --

global $wpdb;

if ($wpdb->get_var("show tables like `" . $wpdb->prefix . $table_name1 . "`") != $wpdb->prefix . $table_name1) {
  // your dbDelta query here
}
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