Unions

The query builder also lets you create union statements on your queries using either UNION or UNION ALL strategies.

The union methods take either a Query Builder instance or a closure which you use to define a new QueryBuilder instance.

Union statements are added in the order in which the union methods are invoked, but the union statements can be in any order in your API call stack. This means you can safely declare your union method calls before the select, from and orderBy calls on the source Query Builder instance.

  • union() — This method builds a SQL statement using the UNION clause which combines two SQL queries into a single result set containing all the matching rows. The two queries must have the same defined columns and compatible data types or the SQL engine will generate an error. The union clause only returns unique rows.

  • unionAll() — This builds a SQL statement using the UNION ALL clause. This is the same as union but includes duplicate rows.

IMPORTANT: The QueryBuilder instances passed to a union statement cannot contain a defined order. Any use of the orderBy() method on the unioned QueryBuilder instances will result in an OrderByNotAllowedexception. To order the results, add an orderBy() call to the parent source Query Builder instance.

union

Adds a UNION statement to the query.

QueryBuilder
query.from( "users" )
    .select( "name" )
    .where( "id", 1 )
    .union( function ( q ) {
        q.from( "users" )
            .select( "name" )
            .where( "id", 2 );
    } );
MySQL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION
SELECT `name`
FROM `users`
WHERE `id` = ?

Adding multiple union statements will append it to the query.

QueryBuilder
query.from( "users" )
    .select( "name" )
    .where( "id", 1 )
    .union( function ( q ) {
        q.from( "users" )
            .select( "name" )
            .where( "id", 2 );
    } )
    .union( function ( q ) {
        q.from( "users" )
            .select("name")
            .where( "id", 3 );
    } );
MySQL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION
SELECT `name`
FROM `users`
WHERE `id` = ?

It can also add union queries as QueryBuilder instances.

QueryBuilder
var q1 = query.newQuery()
    .from( "users" )
    .select( "name" )
    .where( "id", 2 );
    
var q2 = query.newQuery()
    .from( "users" )
    .select( "name" )
    .where( "id", 3 );

query.from( "users" )
    .select( "name" )
    .where( "id", 1 )
    .union( q1 )
    .union( q2 );
MySQL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION
SELECT `name`
FROM `users`
WHERE `id` = ?

unionAll

Adds a UNION ALL statement to the query.

QueryBuilder
query.from( "users" )
    .select( "name" )
    .where( "id", 1 )
    .unionAll( function( q ) {
        q.from( "users" )
            .select( "name" )
            .where( "id", 2 );
     } );
MySQL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION ALL
SELECT `name`
FROM `users`
WHERE `id` = ?

Adding multiple unionAll statements will append it to the query.

QueryBuilder
query.from( "users" )
    .select( "name" )
    .where( "id", 1 )
    .unionAll( function( q ) {
        q.from( "users" )
            .select( "name" )
            .where( "id", 2 );
     } )
    .unionAll( function( q ) {
        q.from( "users" )
            .select( "name" )
            .where( "id", 3 );
     } );
MySQL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION ALL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION ALL
SELECT `name`
FROM `users`
WHERE `id` = ?

It can also add union queries as QueryBuilder instances.

QueryBuilder
var q1 = query.newQuery()
    .from( "users" )
    .select( "name" )
    .where( "id", 2 );
    
var q2 = query.newQuery()
    .from( "users" )
    .select( "name" )
    .where( "id", 3 );

query.from( "users" )
    .select( "name" )
    .where( "id", 1 )
    .unionAll( q1 )
    .unionAll( q2 );
MySQL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION ALL
SELECT `name`
FROM `users`
WHERE `id` = ?
UNION ALL
SELECT `name`
FROM `users`
WHERE `id` = ?

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