How to Update Data in a Table using wpdb in a WordPress Plugin
Posted on 16th June 2023
If you’re a WordPress plugin developer, there are a few things you need to know in order to work with databases. In particular, you need to know how to update data in a table using wpdb.
The wpdb class is the core class used for interacting with a WordPress database. It is possible to perform most database operations using wpdb. However, for more complex operations, you may need to use other WordPress functions such as $wpdb->get_results().
In order to update data in a table using wpdb, you need to first identify the table you want to update. You can do this by running a query on the $wpdb->tables table. This table contains a list of all the tables in the WordPress database.
Once you have identified the table you want to update, you need to identify the row you want to update. You can do this by running a query on the $wpdb->get_row function. This function will return a single row from the table you specify.
Finally, you need to identify the column you want to update. You can do this by running a query on the $wpdb->get_col function. This function will return a single column from the table you specify.
Once you have identified the table, row, and column you want to update, you can use the $wpdb->update function to update the data. This function takes three parameters: the table name, the data to be updated, and the where clause.
The table name is the name of the table you want to update. The data to be updated is an associative array of the data you want to update. The where clause is used to specify the row you want to update.
The $wpdb->update function will return true if the data was updated successfully and false if it was not.
Here is an example of how to use the $wpdb->update function to update data in a table:
$wpdb->update(
‘table_name’,
array(
‘column_name’ => ‘value’,
),
array(
‘ID’ => 1,
)
);
This example will update the column_name column in the table_name table with the value “value” where the ID is 1.
It is also possible to update multiple rows at once using the $wpdb->update function. To do this, you need to specify the where clause as an array of values.
Here is an example of how to update multiple rows at once:
$wpdb->update(
‘table_name’,
array(
‘column_name’ => ‘value’,
),
array(
‘ID’ => array(1,2,3),
)
);
This example will update the column_name column in the table_name table with the value “value” where the ID is 1, 2, or 3.
You can also update multiple columns at once using the $wpdb->update function. To do this, you need to specify the data to be updated as an associative array of column names and values.
Here is an example of how to update multiple columns at once:
$wpdb->update(
‘table_name’,
array(
‘column_name1’ => ‘value1’,
‘column_name2’ => ‘value2’,
‘column_name3’ => ‘value3’,
),
array(
‘ID’ => 1,
)
);
This example will update the column_name1, column_name2, and column_name3 columns in the table_name table with the values “value1”, “value2”, and “value3” where the ID is 1.
In the next section, we will look at how to update data in a table using the wpdb class. We will use the update() method.
This method takes 3 parameters:
The first parameter is the name of the table to update.
The second parameter is an array of data to update. The array keys are the column names and the array values are the new values.
The third parameter is an array of conditions. The array keys are the column names and the array values are the values to check against.
Here is an example:
$wpdb->update(
‘wp_posts’,
array(
‘post_title’ => ‘Hello World’, // string
‘post_content’ => ‘This is a post.’, // string
‘post_date’ => ‘2019-01-01 00:00:00’ // string
),
array(
‘ID’ => 1 // integer
)
);
This would update the post with an ID of 1. The post_title would be changed to “Hello World”, the post_content would be changed to “This is a post” and the post_date would be changed to “2019-01-01 00:00:00”.
You can also update multiple rows at once by passing an array of data to the update() method. The array keys are the row IDs and the array values are the data to update for each row.
$wpdb->update(
‘wp_posts’,
array(
1 => array(
‘post_title’ => ‘Hello World’,
‘post_content’ => ‘This is a post.’,
‘post_date’ => ‘2019-01-01 00:00:00’
),
2 => array(
‘post_title’ => ‘Hello World 2’,
‘post_content’ => ‘This is a post 2.’,
‘post_date’ => ‘2019-01-02 00:00:00’
),
3 => array(
‘post_title’ => ‘Hello World 3’,
‘post_content’ => ‘This is a post 3.’,
‘post_date’ => ‘2019-01-03 00:00:00’
)
),
array(
‘ID’ => array(1,2,3) // integer
)
);
This would update the posts with an ID of 1, 2 and 3. The post_title would be changed to “Hello World”, “Hello World 2” and “Hello World 3” respectively, the post_content would be changed to “This is a post”, “This is a post 2” and “This is a post 3” respectively and the post_date would be changed to “2019-01-01 00:00:00”, “2019-01-02 00:00:00” and “2019-01-03 00:00:00” respectively.
You can also update multiple columns at once by passing an array of data to the update() method. The array keys are the column names and the array values are the data to update for each column.
$wpdb->update(
‘wp_posts’,
array(
‘post_title’ => array(
1 => ‘Hello World’,
2 => ‘Hello World 2’,
3 => ‘Hello World 3’
),
‘post_content’ => array(
1 => ‘This is a post.’,
2 => ‘This is a post 2.’,
3 => ‘This is a post 3.’
),
‘post_date’ => array(
1 => ‘2019-01-01 00:00:00’,
2 => ‘2019-01-02 00:00:00’,
3 => ‘2019-01-03 00:00:00’
)
),
array(
‘ID’ => array(1,2,3) // integer
)
);
This would update the posts with an ID of 1, 2 and 3. The post_title would be changed to “Hello World”, “Hello World 2” and “Hello World 3” respectively, the post_content would be changed to “This is a post”, “This is a post 2” and “This is a post 3” respectively and the post_date would be changed to “2019-01-01 00:00:00”, “2019-01-02 00:00:00” and “2019-01-03 00:00:00” respectively.
