A WPDB wrapper and query builder library.

1.1.1 2024-06-06 20:03 UTC

This package is auto-updated.

Last update: 2024-11-21 18:32:27 UTC


README

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A WPDB wrapper and query builder library. Authored by the development team at StellarWP and provided free for the WordPress community.

Inspired and largely forked from the GiveWP codebase!

Installation

It's recommended that you install DB as a project dependency via Composer:

composer require stellarwp/db

We actually recommend that this library gets included in your project using Strauss.

Luckily, adding Strauss to your composer.json is only slightly more complicated than adding a typical dependency, so checkout our strauss docs.

Table of contents

Quick start

Getting up and running with this library is easy. You'll want to initialize the DB class. Doing so during the plugins_loaded action is a reasonable location, though you can do it anywhere that feels appropriate.

For this example and all future ones, let's assume you have included this library with Strauss and your project's namespace is Boom\Shakalaka.

use Boom\Shakalaka\StellarWP\DB\DB;

add_action( 'plugins_loaded', function() {
	DB::init();
}, 0 );

The two main classes that make up the core of this library are the DB class and the QueryBuilder class. Here are their namespaces:

# For DB, it is "StellarWP\DB\DB", but with your namespace prefix it'll be:
use Boom\Shakalaka\StellarWP\DB\DB;

# For QueryBuilder, it is "StellarWP\DB\QueryBuilder\QueryBuilder", but with your namespace prefix it'll be:
use Boom\Shakalaka\StellarWP\DB\QueryBuilder\QueryBuilder;

Configuration

This library provides default hooks and exceptions, however, if you have additional needs for your own application, you can override one or both via the StellarWP\DB\Config class:

use Boom\Shakalaka\StellarWP\DB\Config;

// Ensure hooks are prefixed with your project's prefix.
Config::setHookPrefix( 'boom_shakalaka' );

// Use your own exception class rather than the default Database\Exceptions\DatabaseQueryException class.
Config::setDatabaseQueryException( 'MyCustomException' );

// Fetch the hook prefix.
$prefix = Config::getHookPrefix();

// Fetch the database query exception class.
$class = Config::getDatabaseQueryException();

DB

DB class is a static decorator for the $wpdb class, but it has a few methods that are exceptions to that. Methods DB::table() and DB::raw().

DB::table() is a static facade for the QueryBuilder class, and it accepts two string arguments, $tableName and $tableAlias.

Under the hood, DB::table() will create a new QueryBuilder instance, and it will use QueryBuilder::from method to set the table name. Calling QueryBuilder::from when using DB::table method will return an unexpected result. Basically, we are telling the QueryBuilder that we want to select data from two tables.

Important

When using DB::table(tableName) method, the tableName is prefixed with $wpdb->prefix. To bypass that, you can use DB::raw method which will tell QueryBuilder not to prefix the table name.

DB::table(DB::raw('posts'));

Select statements

Available methods - select / selectRaw / distinct

By using the QueryBuilder::select method, you can specify a custom SELECT statement for the query.

DB::table('posts')->select('ID', 'post_title', 'post_date');

Generated SQL

SELECT ID, post_title, post_date FROM wp_posts

You can also specify the column alias by providing an array [column, alias] to the QueryBuilder::select method.

DB::table('posts')->select(
    ['ID', 'post_id'],
    ['post_status', 'status'],
    ['post_date', 'createdAt']
);

Generated SQL:

SELECT ID AS post_id, post_status AS status, post_date AS createdAt FROM wp_posts

The distinct method allows you to force the query to return distinct results:

DB::table('posts')->select('post_status')->distinct();

You can also specify a custom SELECT statement with QueryBuilder::selectRaw method. This method accepts an optional array of bindings as its second argument.

DB::table('posts')
    ->select('ID')
    ->selectRaw('(SELECT ID from wp_posts WHERE post_status = %s) AS subscriptionId', 'give_subscription');

Generated SQL

SELECT ID, (SELECT ID from wp_posts WHERE post_status = 'give_subscription') AS subscriptionId FROM wp_posts

By default, all columns will be selected from a database table.

DB::table('posts');

Generated SQL

SELECT * FROM wp_posts

From clause

By using the QueryBuilder::from() method, you can specify a custom FROM clause for the query.

$builder = new QueryBuilder();
$builder->from('posts');

Set multiple FROM clauses

$builder = new QueryBuilder();
$builder->from('posts');
$builder->from('postmeta');

Generated SQL

SELECT * FROM wp_posts, wp_postmeta

Important

Table name is prefixed with $wpdb->prefix. To bypass that, you can use DB::raw method which will tell QueryBuilder not to prefix the table name.

$builder = new QueryBuilder();
$builder->from(DB::raw('posts'));

Joins

The Query Builder may also be used to add JOIN clauses to your queries.

Available methods - leftJoin / rightJoin / innerJoin / joinRaw / join

LEFT Join

LEFT JOIN clause.

DB::table('posts', 'donationsTable')
    ->select('donationsTable.*', 'metaTable.*')
    ->leftJoin('give_donationmeta', 'donationsTable.ID', 'metaTable.donation_id', 'metaTable');

Generated SQL

SELECT donationsTable.*, metaTable.* FROM wp_posts AS donationsTable LEFT JOIN wp_give_donationmeta metaTable ON donationsTable.ID = metaTable.donation_id

RIGHT Join

RIGHT JOIN clause.

DB::table('posts', 'donationsTable')
    ->select('donationsTable.*', 'metaTable.*')
    ->rightJoin('give_donationmeta', 'donationsTable.ID', 'metaTable.donation_id', 'metaTable');

Generated SQL

SELECT donationsTable.*, metaTable.* FROM wp_posts AS donationsTable RIGHT JOIN wp_give_donationmeta metaTable ON donationsTable.ID = metaTable.donation_id

INNER Join

INNER JOIN clause.

DB::table('posts', 'donationsTable')
    ->select('donationsTable.*', 'metaTable.*')
    ->innerJoin('give_donationmeta', 'donationsTable.ID', 'metaTable.donation_id', 'metaTable');

Generated SQL

SELECT donationsTable.*, metaTable.* FROM wp_posts AS donationsTable INNER JOIN wp_give_donationmeta metaTable ON donationsTable.ID = metaTable.donation_id

Join Raw

Insert a raw expression into query.

DB::table('posts', 'donationsTable')
    ->select('donationsTable.*', 'metaTable.*')
    ->joinRaw('LEFT JOIN give_donationmeta metaTable ON donationsTable.ID = metaTable.donation_id');

Generated SQL

SELECT donationsTable.*, metaTable.* FROM wp_posts AS donationsTable LEFT JOIN give_donationmeta metaTable ON donationsTable.ID = metaTable.donation_id

Advanced Join Clauses

The closure will receive a Give\Framework\QueryBuilder\JoinQueryBuilder instance

DB::table('posts')
    ->select('donationsTable.*', 'metaTable.*')
    ->join(function (JoinQueryBuilder $builder) {
        $builder
            ->leftJoin('give_donationmeta', 'metaTable')
            ->on('donationsTable.ID', 'metaTable.donation_id')
            ->andOn('metaTable.meta_key', 'some_key', $qoute = true);
    });

Generated SQL

SELECT donationsTable.*, metaTable.* FROM wp_posts LEFT JOIN wp_give_donationmeta metaTable ON donationsTable.ID = metaTable.donation_id AND metaTable.meta_key = 'some_key'

Unions

The Query Builder also provides a convenient method to "union" two or more queries together.

Available methods - union / unionAll

Union

$donations = DB::table('give_donations')->where('author_id', 10);

DB::table('give_subscriptions')
    ->select('ID')
    ->where('ID', 100, '>')
    ->union($donations);

Generated SQL:

SELECT ID FROM wp_give_subscriptions WHERE ID > '100' UNION SELECT * FROM wp_give_donations WHERE author_id = '10'

Where Clauses

You may use the Query Builder's where method to add WHERE clauses to the query.

Where

Available methods - where / orWhere

DB::table('posts')->where('ID', 5);

Generated SQL

SELECT * FROM wp_posts WHERE ID = '5'

Using where multiple times.

DB::table('posts')
    ->where('ID', 5)
    ->where('post_author', 10);

Generated SQL

SELECT * FROM wp_posts WHERE ID = '5' AND post_author = '10'

Where IN Clauses

Available methods - whereIn / orWhereIn / whereNotIn / orWhereNotIn

The QueryBuilder::whereIn method verifies that a given column's value is contained within the given array:

DB::table('posts')->whereIn('ID', [1, 2, 3]);

Generated SQL

SELECT * FROM wp_posts WHERE ID IN ('1','2','3')

You can also pass a closure as the second argument which will generate a subquery.

The closure will receive a Give\Framework\QueryBuilder\QueryBuilder instance

DB::table('posts')
    ->whereIn('ID', function (QueryBuilder $builder) {
        $builder
            ->select(['meta_value', 'donation_id'])
            ->from('give_donationmeta')
            ->where('meta_key', 'donation_id');
    });

Generated SQL

SELECT * FROM wp_posts WHERE ID IN (SELECT meta_value AS donation_id FROM wp_give_donationmeta WHERE meta_key = 'donation_id')

Where BETWEEN Clauses

The QueryBuilder::whereBetween method verifies that a column's value is between two values:

Available methods - whereBetween / orWhereBetween / whereNotBetween / orWhereNotBetween

DB::table('posts')->whereBetween('ID', 0, 100);

Generated SQL

SELECT * FROM wp_posts WHERE ID BETWEEN '0' AND '100'

Where LIKE Clauses

The QueryBuilder::whereLike method searches for a specified pattern in a column.

Available methods - whereLike / orWhereLike / whereNotLike / orWhereNotLike

DB::table('posts')->whereLike('post_title', 'Donation');

Generated SQL

SELECT * FROM wp_posts WHERE post_title LIKE '%Donation%'

Where IS NULL Clauses

The QueryBuilder::whereIsNull method verifies that a column's value is NULL

Available methods - whereIsNull / orWhereIsNull / whereIsNotNull / orWhereIsNotNull

DB::table('posts')->whereIsNull('post_author');

Generated SQL

SELECT * FROM wp_posts WHERE post_author IS NULL

Where EXISTS Clauses

The QueryBuilder::whereExists method allows you to write WHERE EXISTS SQL clauses. The QueryBuilder::whereExists method accepts a closure which will receive a QueryBuilder instance.

Available methods - whereExists / whereNotExists

DB::table('give_donationmeta')
    ->whereExists(function (QueryBuilder $builder) {
        $builder
            ->select(['meta_value', 'donation_id'])
            ->where('meta_key', 'donation_id');
    });

Generated SQL

SELECT * FROM wp_give_donationmeta WHERE EXISTS (SELECT meta_value AS donation_id WHERE meta_key = 'donation_id')

Subquery Where Clauses

Sometimes you may need to construct a WHERE clause that compares the results of a subquery to a given value.

DB::table('posts')
    ->where('post_author', function (QueryBuilder $builder) {
        $builder
            ->select(['meta_value', 'author_id'])
            ->from('postmeta')
            ->where('meta_key', 'donation_id')
            ->where('meta_value', 10);
    });

Generated SQL

SELECT * FROM wp_posts WHERE post_author = (SELECT meta_value AS author_id FROM wp_postmeta WHERE meta_key = 'donation_id' AND meta_value = '10')

Nested Where Clauses

Sometimes you may need to construct a WHERE clause that has nested WHERE clauses.

The closure will receive a Give\Framework\QueryBuilder\WhereQueryBuilder instance

DB::table('posts')
    ->where('post_author', 10)
    ->where(function (WhereQueryBuilder $builder) {
        $builder
            ->where('post_status', 'published')
            ->orWhere('post_status', 'donation')
            ->whereIn('ID', [1, 2, 3]);
    });

Generated SQL

SELECT * FROM wp_posts WHERE post_author = '10' AND ( post_status = 'published' OR post_status = 'donation' AND ID IN ('1','2','3'))

Ordering, Grouping, Limit & Offset

Ordering

The QueryBuilder::orderBy method allows you to sort the results of the query by a given column.

DB::table('posts')->orderBy('ID');

Generated SQL

SELECT * FROM wp_posts ORDER BY ID ASC

Sorting result by multiple columns

DB::table('posts')
    ->orderBy('ID')
    ->orderBy('post_date', 'DESC');

Generated SQL

SELECT * FROM wp_posts ORDER BY ID ASC, post_date DESC

Grouping

The QueryBuilder::groupBy and QueryBuilder::having* methods are used to group the query results.

Available methods - groupBy / having / orHaving / havingCount / orHavingCount / havingMin / orHavingMin / havingMax / orHavingMax / havingAvg / orHavingAvg / havingSum / orHavingSum / havingRaw

DB::table('posts')
    ->groupBy('id')
    ->having('id', '>', 10);

Generated SQL

SELECT * FROM wp_posts WHERE GROUP BY id HAVING 'id' > '10'

Limit & Offset

Limit the number of results returned from the query.

Available methods - limit / offset

DB::table('posts')
    ->limit(10)
    ->offset(20);

Generated SQL

SELECT * FROM wp_posts LIMIT 10 OFFSET 20

Special methods for working with meta tables

Query Builder has a few special methods for abstracting the work with meta tables.

attachMeta

attachMeta is used to include meta table meta_key column values as columns in the SELECT statement.

Under the hood QueryBuilder::attachMeta will add join clause for each defined meta_key column. And each column will be added in select statement as well, which means the meta columns will be returned in query result. Aliasing meta columns is recommended when using QueryBuilder::attachMeta method.

DB::table('posts')
    ->select(
        ['ID', 'id'],
        ['post_date', 'createdAt'],
        ['post_modified', 'updatedAt'],
        ['post_status', 'status'],
        ['post_parent', 'parentId']
    )
    ->attachMeta('give_donationmeta', 'ID', 'donation_id',
        ['_give_payment_total', 'amount'],
        ['_give_payment_currency', 'paymentCurrency'],
        ['_give_payment_gateway', 'paymentGateway'],
        ['_give_payment_donor_id', 'donorId'],
        ['_give_donor_billing_first_name', 'firstName'],
        ['_give_donor_billing_last_name', 'lastName'],
        ['_give_payment_donor_email', 'donorEmail'],
        ['subscription_id', 'subscriptionId']
    )
    ->leftJoin('give_donationmeta', 'ID', 'donationMeta.donation_id', 'donationMeta')
    ->where('post_type', 'give_payment')
    ->where('post_status', 'give_subscription')
    ->where('donationMeta.meta_key', 'subscription_id')
    ->where('donationMeta.meta_value', 1)
    ->orderBy('post_date', 'DESC');

Generated SQL:

SELECT ID                                         AS id,
       post_date                                  AS createdAt,
       post_modified                              AS updatedAt,
       post_status                                AS status,
       post_parent                                AS parentId,
       give_donationmeta_attach_meta_0.meta_value AS amount,
       give_donationmeta_attach_meta_1.meta_value AS paymentCurrency,
       give_donationmeta_attach_meta_2.meta_value AS paymentGateway,
       give_donationmeta_attach_meta_3.meta_value AS donorId,
       give_donationmeta_attach_meta_4.meta_value AS firstName,
       give_donationmeta_attach_meta_5.meta_value AS lastName,
       give_donationmeta_attach_meta_6.meta_value AS donorEmail,
       give_donationmeta_attach_meta_7.meta_value AS subscriptionId
FROM wp_posts
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_0
                   ON ID = give_donationmeta_attach_meta_0.donation_id AND
                      give_donationmeta_attach_meta_0.meta_key = '_give_payment_total'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_1
                   ON ID = give_donationmeta_attach_meta_1.donation_id AND
                      give_donationmeta_attach_meta_1.meta_key = '_give_payment_currency'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_2
                   ON ID = give_donationmeta_attach_meta_2.donation_id AND
                      give_donationmeta_attach_meta_2.meta_key = '_give_payment_gateway'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_3
                   ON ID = give_donationmeta_attach_meta_3.donation_id AND
                      give_donationmeta_attach_meta_3.meta_key = '_give_payment_donor_id'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_4
                   ON ID = give_donationmeta_attach_meta_4.donation_id AND
                      give_donationmeta_attach_meta_4.meta_key = '_give_donor_billing_first_name'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_5
                   ON ID = give_donationmeta_attach_meta_5.donation_id AND
                      give_donationmeta_attach_meta_5.meta_key = '_give_donor_billing_last_name'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_6
                   ON ID = give_donationmeta_attach_meta_6.donation_id AND
                      give_donationmeta_attach_meta_6.meta_key = '_give_payment_donor_email'
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_7
                   ON ID = give_donationmeta_attach_meta_7.donation_id AND
                      give_donationmeta_attach_meta_7.meta_key = 'subscription_id'
         LEFT JOIN wp_give_donationmeta donationMeta ON ID = donationMeta.donation_id
WHERE post_type = 'give_payment'
  AND post_status = 'give_subscription'
  AND donationMeta.meta_key = 'subscription_id'
  AND donationMeta.meta_value = '1'
ORDER BY post_date DESC

Returned result:

stdClass Object
(
    [id] => 93
    [createdAt] => 2022-02-21 00:00:00
    [updatedAt] => 2022-01-21 11:08:09
    [status] => give_subscription
    [parentId] => 92
    [amount] => 100.000000
    [paymentCurrency] => USD
    [paymentGateway] => manual
    [donorId] => 1
    [firstName] => Ante
    [lastName] => Laca
    [donorEmail] => dev-email@flywheel.local
    [subscriptionId] => 1
)

Fetch multiple instances of the same meta key

Sometimes we need to fetch multiple instances of the same meta key. This is possible by setting the third parameter to true, example ['additional_email', 'additionalEmails', true]

DB::table('give_donors')
  ->select(
      'id',
      'email',
      'name'
  )
  ->attachMeta(
      'give_donormeta',
      'id',
      'donor_id',
  	  ['additional_email', 'additionalEmails', true]
  );

Generated SQL:

SELECT id, email, name, GROUP_CONCAT(DISTINCT give_donormeta_attach_meta_0.meta_value) AS additionalEmails
FROM wp_give_donors
    LEFT JOIN wp_give_donormeta give_donormeta_attach_meta_0 ON id = give_donormeta_attach_meta_0.donor_id AND give_donormeta_attach_meta_0.meta_key = 'additional_email'
GROUP BY id

Returned result:

Instances with the same key, in this case additional_email, will be concatenated into JSON array string.

Array
(
    [0] => stdClass Object
        (
            [id] => 1
            [email] => bill@flywheel.local
            [name] => Bill Murray
            [additionalEmails] => ["email1@lywheel.local","email2@lywheel.local"]
        )

    [1] => stdClass Object
        (
            [id] => 2
            [email] => jon@flywheel.local
            [name] => Jon Waldstein
            [additionalEmails] => ["email3@lywheel.local","email4@lywheel.local","email5@lywheel.local"]
        )

    [2] => stdClass Object
        (
            [id] => 3
            [email] => ante@flywheel.local
            [name] => Ante laca
            [additionalEmails] =>
        )

)

configureMetaTable

By default, QueryBuilder::attachMeta will use meta_key, and meta_value as meta table column names, but that sometimes might not be the case.

With QueryBuilder::configureMetaTable you can define a custom meta_key and meta_value column names.

DB::table('posts')
    ->select(
        ['ID', 'id'],
        ['post_date', 'createdAt']
    )
    ->configureMetaTable(
        'give_donationmeta',
        'custom_meta_key',
        'custom_meta_value'
    )
    ->attachMeta(
        'give_donationmeta',
        'ID',
        'donation_id',
        ['_give_payment_total', 'amount']
    )
    ->leftJoin('give_donationmeta', 'ID', 'donationMeta.donation_id', 'donationMeta')
    ->where('post_type', 'give_payment')
    ->where('post_status', 'give_subscription')
    ->where('donationMeta.custom_meta_key', 'subscription_id')
    ->where('donationMeta.custom_meta_value', 1);

Generated SQL

SELECT ID AS id, post_date AS createdAt, give_donationmeta_attach_meta_0.custom_meta_value AS amount
FROM wp_posts
         LEFT JOIN wp_give_donationmeta give_donationmeta_attach_meta_0
                   ON ID = give_donationmeta_attach_meta_0.donation_id AND
                      give_donationmeta_attach_meta_0.custom_meta_key = '_give_payment_total'
         LEFT JOIN wp_give_donationmeta donationMeta ON ID = donationMeta.donation_id
WHERE post_type = 'give_payment'
  AND post_status = 'give_subscription'
  AND donationMeta.custom_meta_key = 'subscription_id'
  AND donationMeta.custom_meta_value = '1'

CRUD

Insert

The QueryBuilder also provides QueryBuilder::insert method that may be used to insert records into the database table.

DB::table('posts')
    ->insert([
        'post_title'   => 'Post Title',
        'post_author'  => 1,
        'post_content' => 'Post Content'
    ]);

Update

In addition to inserting records into the database, the QueryBuilder can also update existing records using the QueryBuilder::update method.

DB::table('posts')
    ->where('post_author', 1)
    ->update([
        'post_title'   => 'Post Title 2',
        'post_content' => 'Post Content 2'
    ]);

Upsert

The QueryBuilder::upsert method may be used to update an existing record or create a new record if it doesn't exist.

// Would result in a new row - Oakland to San Diego for 100.
DB::table('table_name')
    ->upsert(
        ['departure' => 'Oakland', 'destination' => 'San Diego', 'price' => '100'] ,
        ['departure','destination']
    );


// Would update the row that was just inserted - Oakland to San Diego for 99.
DB::table('table_name')
    ->upsert(
        ['departure' => 'Oakland', 'destination' => 'San Diego', 'price' => '99'] ,
        ['departure','destination']
    );

Delete

The QueryBuilder::delete method may be used to delete records from the table.

DB::table('posts')
    ->where('post_author', 1)
    ->delete();

Get

Available methods - get / getAll

Get single row

$post = DB::table('posts')->where('post_author', 1)->get();

Get all rows

$posts = DB::table('posts')->where('post_status', 'published')->getAll();

Inherited from $wpdb

As this is a wrapper for $wpdb, you are able to call all of the methods that $wpdb exposes as well. You simply will need to match the signature of the $wpdb methods when doing so.

While all methods are supported, get_var(), get_col(), esc_like(), and remove_placeholder_escape() are likely of the most interest as there are not equilavents within the library itself.

get_var()

Gets the single meta_value column for the given query.

$meta_value = DB::get_var(
	DB::table( 'postmeta' )
		->select( 'meta_value' )
		->where( 'post_id', 123 )
		->where( 'meta_key', 'some_key' )
		->getSQL()
);

get_col()

Returns an array of values for the column for the given query.

$meta_values = DB::get_col(
	DB::table( 'postmeta' )
		->select( 'meta_value' )
		->where( 'meta_key', 'some_key' )
		->getSQL()
);

esc_like()

Escapes a string with a percent sign in it so it can be safely used with Where LIKE without the percent sign being interpreted as a wildcard character.

$escaped_string = DB::esc_like( 'This string has a % in it that is not a wildcard character' );

$results = DB::table( 'posts' )
    ->whereLike( 'post_content', "%{$escaped_string}%" )
    ->getAll();

remove_placeholder_escape()

Removes the placeholder escape strings from a SQL query.

$wpdb generates placeholders such as {abb19424319f69be9475708db0d2cbb780cb2dc2375bcb2657c701709ff71a9f} that it escapes % with when generating a SQL query. This library, as a $wpdb wrapper, does that as well.

Using DB::remove_placeholder_escape() will swap those back out for %, which can be useful if you ever need to display the query in a more human-friendly format.

$escaped_sql = DB::table( 'postmeta' )
	->whereLike( 'meta_key', '%search string%' )
	->getSql();

$sql = DB::remove_placeholder_escape( $escaped_sql );

Aggregate Functions

The Query Builder also provides a variety of methods for retrieving aggregate values like count, sum, avg, min and max.

Count

$count = DB::table('posts')
    ->where('post_type', 'published')
    ->count();

Count rows where provided column is not null.

$count = DB::table('donations')->count('not_null_value_column');

Sum

$sum = DB::table('give_donationmeta')
    ->where('meta_key', 'donation_amount')
    ->sum('meta_value');

Avg

$avg = DB::table('give_donationmeta')
    ->where('meta_key', 'donation_amount')
    ->avg('meta_value');

Min

$min = DB::table('give_donationmeta')
    ->where('meta_key', 'donation_amount')
    ->min('meta_value');

Max

$max = DB::table('give_donationmeta')
    ->where('meta_key', 'donation_amount')
    ->max('meta_value');

Acknowledgements

Props to the GiveWP team for creating this library!