@@ -30,25 +30,31 @@ Application programs can execute `INSERT` statement through connectors to insert
The below SQL statement is used to insert one row into table "d1001".
```sql
INSERT INTO d1001 VALUES (1538548685000, 10.3, 219, 0.31);
INSERT INTO d1001 VALUES (ts1, 10.3, 219, 0.31);
```
`ts1` is Unix timestamp, the timestamps which is larger than the difference between current time and KEEP in config is only allowed. For further detial, refer to [TDengine SQL insert timestamp section](/taos-sql/insert).
### Insert Multiple Rows
Multiple rows can be inserted in a single SQL statement. The example below inserts 2 rows into table "d1001".
`ts1` and `ts2` is Unix timestamp, the timestamps which is larger than the difference between current time and KEEP in config is only allowed. For further detial, refer to [TDengine SQL insert timestamp section](/taos-sql/insert).
### Insert into Multiple Tables
Data can be inserted into multiple tables in the same SQL statement. The example below inserts 2 rows into table "d1001" and 1 row into table "d1002".
`ts1`, `ts2` and `ts3` is Unix timestamp, the timestamps which is larger than the difference between current time and KEEP in config is only allowed. For further detial, refer to [TDengine SQL insert timestamp section](/taos-sql/insert).
For more details about `INSERT` please refer to [INSERT](/taos-sql/insert).
- The number of rows in the result set of `INTERP` is determined by the parameter `EVERY(time_unit)`. Starting from timestamp1, one interpolation is performed for every time interval specified `time_unit` parameter. The parameter `time_unit` must be an integer, with no quotes, with a time unit of: a(millisecond)), s(second), m(minute), h(hour), d(day), or w(week). For example, `EVERY(500a)` will interpolate every 500 milliseconds.
- Interpolation is performed based on `FILL` parameter. For more information about FILL clause, see [FILL Clause](../distinguished/#fill-clause).
- `INTERP` can only be used to interpolate in single timeline. So it must be used with `partition by tbname` when it's used on a STable.
- Pseudocolumn `_irowts` can be used along with `INTERP` to return the timestamps associated with interpolation points(support after version 3.0.1.4).
- Pseudocolumn `_isfilled` can be used along with `INTERP` to indicate whether the results are original records or data points generated by interpolation algorithm(support after version 3.0.2.3).
- Pseudocolumn `_irowts` can be used along with `INTERP` to return the timestamps associated with interpolation points(support after version 3.0.2.0).
- Pseudocolumn `_isfilled` can be used along with `INTERP` to indicate whether the results are original records or data points generated by interpolation algorithm(support after version 3.0.3.0).
@@ -179,9 +179,10 @@ The parameters described in this document by the effect that they have on the sy
| Attribute | Description |
| -------- | -------------------------------- |
| Applicable | Server only |
| Meaning | count()/hyperloglog() return value or not if the result data is NULL |
| Meaning | count()/hyperloglog() return value or not if the input data is empty or NULL |
| Vlue Range | 0：Return empty line，1：Return 0 |
| Default | 1 |
| Notes | When this parameter is setting to 1, for queries containing GROUP BY, PARTITION BY and INTERVAL clause, and input data in certain groups or windows is empty or NULL, the corresponding groups or windows have no return values |
