dolphineDB 的脚本代码编写查询语句
时间: 2024-09-19 09:07:57 浏览: 40
DolphinDB是一种基于列式存储的数据库系统,其脚本语言DSQL用于编写查询语句。DSQL语法简洁直观,支持各种数据处理操作。以下是编写基本查询语句的一些示例:
1. **选择特定列**:
```dsql
select column1, column2 from table_name;
```
2. **过滤行**:
```dsql
select * from table_name where condition; // 条件可以是字段值等于、大于等
```
3. **排序结果**:
```dsql
select * from table_name order by column1 [asc|desc]; // asc表示升序,desc降序
```
4. **分组统计**:
```dsql
select column1, count(*) as count from table_name group by column1;
```
5. **联接操作**:
```dsql
select * from table1 inner join table2 on table1.commonColumn = table2.commonColumn;
```
6. **创建新表**:
```dsql
create table new_table (column1 datatype, ...);
insert into new_table values (...);
```
7. **实时流处理**(DolphinDB特别之处):
```dsql
streamTable = streamInput(...); // 创建输入流
output = process(streamTable, someFunction); // 执行实时计算
```