A subquery can be used any place where an expression is allowed providing it returns a single value. This means that a subquery that returns a single value can also be listed as an object in a FROM clause listing. This is termed an inline view because when a subquery is used as part ...
be used in subqueries that include a GROUP BY clause. subqueries that include a GROUP BY clause. • Subqueries cannot manipulate their results Subqueries cannot manipulate their results internally. This means that a subquery cannot internally. This means that a subquery cannot ...
For example, the optimizer might be able to use materialization if both expressions are integer or both are decimal, but cannot if one expression is integer and the other is decimal. The inner expression cannot be a BLOB. Use of EXPLAIN with a query provides some indication of whether the...
A subquery that results in a single element is called a scalar subquery. The query result can be used as a scalar operand and has the basic characteristics of a scalar operand, such as the data type, length, and whether it can beNULL. For example, the result returned by the following q...
• The optimization cannot be used if the derived table contains UNION. This restriction is lifted in MySQL 8.0.29. Consider two tables t1 and t2, and a view v containing their union, created as shown here: CREATETABLEt1 ( idINTNOTNULLAUTO_INCREMENTPRIMARYKEY, ...
In MySQL 8.0.17 and later, the subquery can also be the argument to an expression modified by NOT, IS [NOT] TRUE, or IS [NOT] FALSE. • It must be a single SELECT without UNION constructs. • It must not contain a HAVING clause. ...
IN and = ANY are not synonyms when used with an expression list. IN can take an expression list, but = ANY cannot. See Section 14.4.2, “Comparison Functions and Operators”. NOT IN is not an alias for <> ANY, but for <> ALL. See Section 15.2.15.4, “Subqueries with ALL”. ...
NOT IN SUBQUERY is used in a similar manner to LEFT ANTI JOIN. However, if the values of a row are NULL for a specified column in the table that you want to query, the value of the expression in NOT IN SUBQUERY is NULL. In this case, the WHERE condition is invalid, and no data...
These conditions must be connected using AND. Other parts of the subquery cannot contain the column. Other restrictions are as follows:The columns in the expression in the WHERE condition of the subquery must exist in tables.After the SELECT keyword of the subquery, there must be only one ...
The SQL subquery is a SELECT query that is embedded in the main SELECT statement. The subquery can be nested inside a SELECT, INSERT, UPDATE, or DELETE statement or inside another subquery.