# Selects

## Specifying A Select Clause

You may not always want to select all columns from a database table. You can influence the select list of a query with the following methods.

Individual columns can contain fully-qualified names (`some_table.some_column`), table aliases (`alias.some_column`), and even set column aliases themselves (`some_column AS c`). The `columns` argument can be a single column, a list of columns (comma-separated), or an array of columns.

## select <a href="#get" id="get"></a>

| Name    | Type            | Required | Default | Description                                                        |
| ------- | --------------- | -------- | ------- | ------------------------------------------------------------------ |
| columns | string \| array | `false`  | ​`"*"`  | A single column, list of columns, or array of columns to retrieve. |

When calling `select` any previous columns are discarded. If you want to incrementally select columns, use the `addSelect` method.

If you pass no columns to this method, it will default to `"*"`.

{% code title="QueryBuilder" %}

```javascript
query.select( [ "fname AS firstName", "age" ] ).from( "users" );
```

{% endcode %}

{% code title="SQL (MySQL)" %}

```sql
SELECT `name` AS `firstName`, `age` FROM `users`
```

{% endcode %}

## distinct <a href="#get" id="get"></a>

| Name  | Type    | Required | Default | Description                     |
| ----- | ------- | -------- | ------- | ------------------------------- |
| state | boolean | `false`  | ​`true` | Value to set the distinct flag. |

Calling distinct will cause the query to be executed with the `DISTINCT` keyword.

{% code title="QueryBuilder" %}

```javascript
query.select( "username" ).distinct().from( "users" );
```

{% endcode %}

{% code title="SQL (MySQL)" %}

```sql
SELECT DISTINCT `username` FROM `users`
```

{% endcode %}

{% hint style="info" %}
`distinct` applies to the entire query, not just certain fields.
{% endhint %}

## addSelect <a href="#get" id="get"></a>

| Name    | Type            | Required | Default | Description                                                                 |
| ------- | --------------- | -------- | ------- | --------------------------------------------------------------------------- |
| columns | string \| array | `true`   | ​       | A single column, list of columns, or array of columns to add to the select. |

This method adds the columns passed to it to the currently selected columns.

{% hint style="warning" %}
If the `QueryBuilder` is currently selecting all columns (`"*"`) when this method is called, the incoming columns will becoming the only columns selected.
{% endhint %}

{% code title="QueryBuilder" %}

```javascript
query.select( [ "fname AS firstName", "age" ] ).from( "users" );
```

{% endcode %}

{% code title="SQL (MySQL)" %}

```sql
SELECT `name` AS `firstName`, `age` FROM `users`
```

{% endcode %}

## selectRaw <a href="#get" id="get"></a>

| Name       | Type  | Required | Default | Description                                  |
| ---------- | ----- | -------- | ------- | -------------------------------------------- |
| expression | any   | `true`   | ​       | The raw expression for the select statement. |
| bindings   | array | `false`  | `[]`    | Any bindings needed for the raw expression.  |

A shortcut to use a raw expression in the select clause.

The expression is added to the other already selected columns.

*(To learn more about raw and expressions, check out the docs on* [*Raw Expressions*](https://qb.ortusbooks.com/7.10.0/query-builder/building-queries/raw-expressions)*.)*

{% code title="QueryBuilder" %}

```javascript
query.selectRaw( "YEAR(birthdate) AS birth_year" ).from( "users" );
```

{% endcode %}

{% code title="SQL (MySQL)" %}

```sql
SELECT YEAR(birthdate) AS birth_year FROM `users`
```

{% endcode %}

## subSelect <a href="#get" id="get"></a>

| Name  | Type                     | Required | Default | Description                                    |
| ----- | ------------------------ | -------- | ------- | ---------------------------------------------- |
| alias | string                   | `true`   | ​       | The alias for the subselect expression.        |
| query | Function \| QueryBuilder | `true`   |         | The callback or query to use in the subselect. |

The method lets you pass either a callback or a `QueryBuilder` instance to be used as a subselect expression. If a callback is passed it will be passed a new query instance as the only parameter.

The subselect is added to the other already selected columns.

{% code title="QueryBuilder" %}

```javascript
query.subSelect( "last_login_date", function( q ) {
    q.selectRaw( "MAX(created_date)" )
        .from( "logins" )
        .whereColumn( "users.id", "logins.user_id" );
} ) ).from( "users" );
```

{% endcode %}

{% code title="SQL (MySQL)" %}

```sql
SELECT (
    SELECT MAX(created_date)
    FROM `logins`
    WHERE `users`.`id` = `logins`.`user_id`
) AS `last_login_date`
FROM `users
```

{% endcode %}