for select distinct
时间: 2023-11-12 19:18:54 浏览: 35
In order to select distinct values from a table in a SQL query, you can use the keyword "DISTINCT" followed by the column(s) you want to retrieve unique values for. Here's an example:
```sql
SELECT DISTINCT column_name
FROM table_name;
```
Replace "column_name" with the actual column name you want to retrieve distinct values for, and "table_name" with the name of the table you are querying. This query will return only the unique values from the specified column.
相关问题
select distinct
The SELECT DISTINCT statement is used to retrieve only unique records from a table. It is used in conjunction with the SELECT statement to return a result set that contains only unique values for a specific column or set of columns. This is useful when you want to eliminate duplicate values and focus on unique data.
For example, if you have a table of customer orders and you want to find out the unique products that have been ordered, you could use the following SQL statement:
SELECT DISTINCT product_name
FROM orders;
This statement would return a list of all the unique product names that have been ordered, without any duplicates.
Select distinct
" DISTINCT" is a SQL statement used to retrieve unique or distinct values from a database table. It eliminates any duplicate rows that might exist in the result set.
For example, if you have a table named "customers" with columns "id", "name", and "email", you can use the following SQL query to retrieve a list of distinct email addresses:
```
SELECT DISTINCT email FROM customers;
```
This would return a list of unique email addresses from the "customers" table.
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