Notice that the results are limited in the console to about a hundred, by default, due to the **Smart query limit**
feature. This helps users avoid inadvertently running queries that return an excessive amount of data, possibly
overwhelming their system.
7. Let's edit the query directly and take a look at a few more query building features in the editor.
Click in the query edit pane and make the following changes:
1. Add a line after the first column, `"page"` and Start typing the name of a new column, `"countryName"`. Notice that the autocomplete menu suggests column names, functions, keywords, and more. Choose "countryName" and
add the new column to the GROUP BY clause as well, either by name or by reference to its position, `2`.
2. For readability, replace `Count` column name with `Edits`, since the `COUNT()` function actually
returns the number of edits for the page. Make the same column name change in the ORDER BY clause as well.
The `COUNT()` function is one of many functions available for use in Druid SQL queries. You can mouse over a function name
in the autocomplete menu to see a brief description of a function. Also, you can find more information in the Druid
documentation; for example, the `COUNT()` function is documented in
> Another way to view the explain plan is by adding EXPLAIN PLAN FOR to the front of your query, as follows:
>
>```sql
>EXPLAIN PLAN FOR
>SELECT
> "page",
> "countryName",
> COUNT(*) AS "Edits"
>FROM "wikipedia"
>WHERE "countryName" IS NOT NULL
>GROUP BY 1, 2
>ORDER BY "Edits" DESC
>```
>This is particularly useful when running queries
from the command line or over HTTP.
9. Finally, click `...` and **Edit context** to see how you can add additional parameters controlling the execution of the query execution. In the field, enter query context options as JSON key-value pairs, as described in [Context flags](../querying/query-context.md).
That's it! We've built a simple query using some of the query builder features built into the Druid Console. The following
sections provide a few more example queries you can try. Also, see [Other ways to invoke SQL queries](#other-ways-to-invoke-sql-queries) to learn how
to run Druid SQL from the command line or over HTTP.
## More Druid SQL examples
Here is a collection of queries to try out:
### Query over time
```sql
SELECT FLOOR(__time to HOUR) AS HourTime, SUM(deleted) AS LinesDeleted
FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00'
For convenience, the Druid package includes a SQL command-line client, located at `bin/dsql` in the Druid package root.
Let's now run `bin/dsql`; you should see the following prompt:
```bash
Welcome to dsql, the command-line client for Druid SQL.
Type "\h" for help.
dsql>
```
To submit the query, paste it to the `dsql` prompt and press enter:
```bash
dsql> SELECT page, COUNT(*) AS Edits FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00' GROUP BY page ORDER BY Edits DESC LIMIT 10;
You can submit queries directly to the Druid Broker over HTTP.
The tutorial package includes an example file that contains the SQL query shown above at `quickstart/tutorial/wikipedia-top-pages-sql.json`. Let's submit that query to the Druid Broker:
Welcome to dsql, the command-line client for Druid SQL.
Type "\h" for help.
dsql>
```
将SQl粘贴到 `dsql` 中提交查询：
```json
dsql> SELECT page, COUNT(*) AS Edits FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00' GROUP BY page ORDER BY Edits DESC LIMIT 10;
"page": "Total Drama Presents: The Ridonculous Race",
"Edits": 18
},
{
"page": "User talk:Dudeperson176123",
"Edits": 18
},
{
"page": "Wikipédia:Le Bistro/12 septembre 2015",
"Edits": 18
},
{
"page": "Wikipedia:In the news/Candidates",
"Edits": 17
},
{
"page": "Wikipedia:Requests for page protection",
"Edits": 17
}
]
```
#### 更多Druid SQL示例
这是一组可尝试的查询:
**时间查询**
```json
SELECT FLOOR(__time to HOUR) AS HourTime, SUM(deleted) AS LinesDeleted
FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00'
GROUP BY 1
```
**聚合查询**
```json
SELECT channel, page, SUM(added)
FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00'
GROUP BY channel, page
ORDER BY SUM(added) DESC
```
**查询原始数据**
```json
SELECT user, page
FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 02:00:00' AND TIMESTAMP '2015-09-12 03:00:00'
LIMIT 5
```
#### SQL查询计划
Druid SQL能够解释给定查询的查询计划, 在控制台中，可以通过 `...` 按钮访问此功能。
如果您以其他方式查询，则可以通过在Druid SQL查询之前添加 `EXPLAIN PLAN FOR` 来获得查询计划。
使用上边的一个示例：
`EXPLAIN PLAN FOR SELECT page, COUNT(*) AS Edits FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00' GROUP BY page ORDER BY Edits DESC LIMIT 10;`
```json
dsql> EXPLAIN PLAN FOR SELECT page, COUNT(*) AS Edits FROM wikipedia WHERE "__time" BETWEEN TIMESTAMP '2015-09-12 00:00:00' AND TIMESTAMP '2015-09-13 00:00:00' GROUP BY page ORDER BY Edits DESC LIMIT 10;
