> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries.md).

# Subqueries

{% columns %}
{% column %}
{% content-ref url="/pages/AviU4lFLCp4v9SVcybwW" %}
[Subqueries With ALL](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-and-all.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Compare a value against all results from a subquery. The `ALL` operator returns `TRUE` if the comparison holds for every row returned by the subquery.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/HgVb7wv784EUZZEGEznb" %}
[Subqueries With ANY and SOME](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-and-any.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Compare a value against any result from a subquery. The `ANY` (or `SOME`) operator returns `TRUE` if the comparison holds for at least one row. `IN` can be used for `=ANY`.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/lLtREPbZvVnrkqVx3Fet" %}
[Subqueries With EXISTS](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-and-exists.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Test for the existence of rows. The `EXISTS` operator returns `TRUE` if the subquery returns at least one row, often used for correlated subqueries.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/btd3F3kW9f98blWbV3OE" %}
[Subqueries With JOINs](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-and-joins.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Understand when to use subqueries versus joins. This guide explains performance implications and how to rewrite subqueries as joins for efficiency.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/UOpxCJiQoT2irvPtK9pF" %}
[Subqueries in a FROM Clause (Derived Tables)](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-in-a-from-clause-derived-tables.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Use a subquery as a temporary table. Derived tables allow you to select from the result set of another query within the `FROM` clause.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/POig64cbRhBaNgokN4y8" %}
[Row Subqueries](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-row-subqueries.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Retrieve a single row of multiple values. A row subquery returns a tuple that can be compared against a row constructor in the outer query.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/X2lcYDHOCjDxwLSEDufJ" %}
[Scalar Subqueries](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subqueries-scalar-subqueries.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Return a single value. A scalar subquery produces a one-row, one-column result that can be used anywhere a constant or expression is valid.
{% endcolumn %}
{% endcolumns %}

{% columns %}
{% column %}
{% content-ref url="/pages/r9NLkVkrZbE8XSx3JUgu" %}
[Subquery Limitations](/docs/server/reference/sql-statements/data-manipulation/selecting-data/subqueries/subquery-limitations.md)
{% endcontent-ref %}
{% endcolumn %}

{% column %}
Review restrictions on subquery usage. This page details unsupported operations, such as modifying a table while selecting from it in a subquery.
{% endcolumn %}
{% endcolumns %}