If we want to sum same column’s value, we must use sum() aggregate function.

**Example**: Find the total page count of all books.

**Answer**:

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Select sum(pageCount) from books. |

If we want to sum different columns value then we must use + (plus) operator on the query.

**Example**: List pagecount, point and sum of pagecount and point columns values.

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Select pagecount, point, point + pagecount as total from books. |

If we want to find sum of two variables value then the example below.

**Example**

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Set @a = 5; Set @b = 10; Select @a + @b as total; |