mysql group by like
时间: 2023-06-21 13:12:37 浏览: 62
在 MySQL 中,`GROUP BY` 用于将结果集按照一个或多个列分组,然后对每个组应用聚合函数(例如 `SUM()`、`COUNT()`、`AVG()` 等)。
如果你想在 `GROUP BY` 子句中使用 `LIKE`,可以使用以下语法:
```sql
SELECT column1, column2, SUM(column3)
FROM table_name
WHERE column1 LIKE '%keyword%'
GROUP BY column1, column2
```
注意,在 `GROUP BY` 子句中指定的所有列都必须出现在 `SELECT` 子句中。如果你只想按照一个列分组,并且在 `SELECT` 子句中只选择了该列和聚合函数,那么可以使用 `DISTINCT` 关键字来达到相同的效果:
```sql
SELECT DISTINCT column1, SUM(column2)
FROM table_name
WHERE column1 LIKE '%keyword%'
GROUP BY column1
```
相关问题
mysqlgroup by
GROUP BY is a clause in MySQL used to group rows based on one or more columns. It is often used in combination with aggregate functions like SUM, AVG, COUNT, etc., to perform calculations on specific groups of data rather than the entire dataset.
For example, let's say we have a table called "sales" with columns like "product_name," "category," and "quantity_sold." We want to find the total quantity sold for each category. We can use the GROUP BY clause to achieve this:
```sql
SELECT category, SUM(quantity_sold) as total_quantity
FROM sales
GROUP BY category;
```
This query will group the rows based on the "category" column and calculate the sum of "quantity_sold" for each category. The result will be a set of rows, each representing a category and its corresponding total quantity sold.
Note that when using GROUP BY, the SELECT clause can only contain columns that are either part of the GROUP BY clause or used with aggregate functions.
mysql group by avg_mysql~group by
`GROUP BY` is a MySQL clause that is used to group the result set based on one or more columns. The `AVG()` function is an aggregate function in MySQL that is used to calculate the average value of a set of values.
To use `GROUP BY` and `AVG()` together in MySQL, you can do something like this:
```
SELECT column1, AVG(column2)
FROM table_name
GROUP BY column1;
```
This will group the result set by values in `column1` and then calculate the average value of `column2` for each group.
For example, if you have a table called `sales` with columns `region` and `sales_amount`, you could use the following query to get the average sales amount for each region:
```
SELECT region, AVG(sales_amount)
FROM sales
GROUP BY region;
```