What does in mean in mysql?

The IN operator in MySQL is used to check whether the value is in the specified value list and returns a Boolean value. It works by comparing the query value with each value in the list and returns true if there is a match, false otherwise. Performance is affected by the number of list values, and for large lists of values ​​it is more efficient to use subqueries or temporary tables.

IN operator in MySQL

IN operator is used to check whether a value is included in the specified value list middle. It returns a boolean value, true if the value is in the list, false if it is not in the list.

Syntax

<code>SELECT column_name
FROM table_name
WHERE column_name IN (value1, value2, ..., valueN);</code>

Example

The following query finds students whose names contain "John" or "Mary":

<code>SELECT name
FROM students
WHERE name IN ('John', 'Mary');</code>

Operation

The IN operator works as follows:

• Compares the query value to each value in the list.
• Returns true if the query value matches any value in the list.
• Returns false if the query value does not match any value in the list.

Performance Notes

• The performance of the IN operator decreases as the number of values ​​in the list increases.
• For lists containing a large number of values, it may be more efficient to use a subquery or a temporary table.

Related operators

• NOT IN: Checks whether a value is not in the specified value list.
• BETWEEN: Checks whether a value is in a list of values ​​within the specified range.

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