@@ -43,7 +43,7 @@ Query OK, 2 row(s) in set (0.001100s)
To meet the requirements of varied use cases, some special functions have been added in TDengine. Some examples are `twa` (Time Weighted Average), `spread` (The difference between the maximum and the minimum), and `last_row` (the last row).
For detailed query syntax, see [Select](../../taos-sql././select).
For detailed query syntax, see [Select](../../taos-sql/select).
## Aggregation among Tables
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@@ -74,7 +74,7 @@ taos> SELECT count(*), max(current) FROM meters where groupId = 2;
Query OK, 1 row(s) in set (0.002136s)
```
In [Select](../../taos-sql././select), all query operations are marked as to whether they support STables or not.
In [Select](../../taos-sql/select), all query operations are marked as to whether they support STables or not.
## Down Sampling and Interpolation
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@@ -122,7 +122,7 @@ In many use cases, it's hard to align the timestamp of the data collected by eac
Interpolation can be performed in TDengine if there is no data in a time range.
For more information, see [Aggregate by Window](../../taos-sql/interval).
For more information, see [Aggregate by Window](../../taos-sql/distinguished).
This section explains the syntax of SQL to perform operations on databases, tables and STables, insert data, select data and use functions. We also provide some tips that can be used in TDengine SQL. If you have previous experience with SQL this section will be fairly easy to understand. If you do not have previous experience with SQL, you'll come to appreciate the simplicity and power of SQL. TDengine SQL has been enhanced in version 3.0, and the query engine has been rearchitected. For information about how TDengine SQL has changed, see [Changes in TDengine 3.0](/taos-sql/changes).
This section explains the syntax of SQL to perform operations on databases, tables and STables, insert data, select data and use functions. We also provide some tips that can be used in TDengine SQL. If you have previous experience with SQL this section will be fairly easy to understand. If you do not have previous experience with SQL, you'll come to appreciate the simplicity and power of SQL. TDengine SQL has been enhanced in version 3.0, and the query engine has been rearchitected. For information about how TDengine SQL has changed, see [Changes in TDengine 3.0](../changes).
TDengine SQL is the major interface for users to write data into or query from TDengine. It uses standard SQL syntax and includes extensions and optimizations for time-series data and services. The maximum length of a TDengine SQL statement is 1 MB. Note that keyword abbreviations are not supported. For example, DELETE cannot be entered as DEL.