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StellarWP DB

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:

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

• Configuration

• DB

• Select statements

• From Clause

• Joins

  • LEFT Join
  • RIGHT Join
  • INNER Join
  • Join Raw
  • Advanced Join Clauses

• Unions

• Where Clauses

  • Where
  • Where IN
  • Where BETWEEN
  • Where LIKE
  • Where IS NULL
  • Where EXISTS
  • Subquery Where Clauses
  • Nested Where Clauses

• Ordering, Grouping, Limit & Offset

  • Ordering
  • Grouping
  • Limit & Offset

• Special methods for working with meta tables

  • attachMeta
  • configureMetaTable

• CRUD

  • Insert
  • Update
  • Upsert
  • Delete
  • Get

• Inherited from $wpdb

  • get_var()
  • get_col()
  • esc_like()
  • remove_placeholder_escape()
• Aggregate Functions
  • Count
  • Sum
  • Avg
  • Min
  • Max

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.

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

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:

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.

Select statements

Available methods - select / selectRaw / distinct

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

Generated SQL

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

Generated SQL:

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

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

Generated SQL

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

Generated SQL

From clause

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

Set multiple FROM clauses

Generated SQL

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.

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.

Generated SQL

RIGHT Join

RIGHT JOIN clause.

Generated SQL

INNER Join

INNER JOIN clause.

Generated SQL

Join Raw

Insert a raw expression into query.

Generated SQL

Advanced Join Clauses

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

Generated SQL

Unions

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

Available methods - union / unionAll

Union

Generated SQL:

Where Clauses

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

Where

Available methods - where / orWhere

Generated SQL

Using where multiple times.

Generated SQL

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:

Generated SQL

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

Generated SQL

Where BETWEEN Clauses

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

Available methods - whereBetween / orWhereBetween / whereNotBetween / orWhereNotBetween

Generated SQL

Where LIKE Clauses

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

Available methods - whereLike / orWhereLike / whereNotLike / orWhereNotLike

Generated SQL

Where IS NULL Clauses

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

Available methods - whereIsNull / orWhereIsNull / whereIsNotNull / orWhereIsNotNull

Generated SQL

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

Generated SQL

Subquery Where Clauses

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

Generated SQL

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

Generated SQL

Ordering, Grouping, Limit & Offset

Ordering

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

Generated SQL

Sorting result by multiple columns

Generated SQL

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

Generated SQL

Limit & Offset

Limit the number of results returned from the query.

Available methods - limit / offset

Generated SQL

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 _metakey 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.

Generated SQL:

Returned result:

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]

Generated SQL:

Returned result:

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

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.

Generated SQL

CRUD

Insert

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

Update

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

Upsert

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

Delete

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

Get

Available methods - get / getAll

Get single row

Get all rows

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.

get_col()

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

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.

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.

Aggregate Functions

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

Count

Count rows where provided column is not null.

Sum

Avg

Min

Max

Acknowledgements

Props to the GiveWP team for creating this library!