From 8d8d1c63610d594ef1a2d428b9ef8c25cefc9ece Mon Sep 17 00:00:00 2001 From: lancelly <1435078631@qq.com> Date: Wed, 28 Feb 2024 16:41:05 +0800 Subject: [PATCH] revert --- .../User-Manual/Operator-and-Expression.md | 3 - .../stage/Operators-Functions/Aggregation.md | 101 +------------ .../User-Manual/Operator-and-Expression.md | 30 ++-- .../stage/Operators-Functions/Aggregation.md | 133 +++-------------- .../Reference/Function-and-Expression.md | 135 +++--------------- .../User-Manual/Operator-and-Expression.md | 26 ++-- .../Reference/Function-and-Expression.md | 100 ------------- .../User-Manual/Operator-and-Expression.md | 2 - 8 files changed, 60 insertions(+), 470 deletions(-) diff --git a/src/UserGuide/Master/User-Manual/Operator-and-Expression.md b/src/UserGuide/Master/User-Manual/Operator-and-Expression.md index 4454f447..5d14be32 100644 --- a/src/UserGuide/Master/User-Manual/Operator-and-Expression.md +++ b/src/UserGuide/Master/User-Manual/Operator-and-Expression.md @@ -114,9 +114,6 @@ The built-in functions can be used in IoTDB without registration, and the functi | COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 | | TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 | | MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type | -| MAX_BY | MAX_BY(x, y) returns the value of x corresponding to the maximum value of the input y. MAX_BY(time, x) returns the timestamp when x is at its maximum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | Consistent with the data type of the first input x. | -| MIN_BY | MIN_BY(x, y) returns the value of x corresponding to the minimum value of the input y. MIN_BY(time, x) returns the timestamp when x is at its minimum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | Consistent with the data type of the first input x. | - For details and examples, see the document [Aggregate Functions](../Operators-Functions/Aggregation.md). diff --git a/src/UserGuide/Master/stage/Operators-Functions/Aggregation.md b/src/UserGuide/Master/stage/Operators-Functions/Aggregation.md index afcbadac..201fa0b3 100644 --- a/src/UserGuide/Master/stage/Operators-Functions/Aggregation.md +++ b/src/UserGuide/Master/stage/Operators-Functions/Aggregation.md @@ -43,8 +43,6 @@ The aggregate functions supported by IoTDB are as follows: | TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 | | MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type | | COUNT_TIME | The number of timestamps in the query data set. When used with `align by device`, the result is the number of timestamps in the data set per device. | All data Types, the input parameter can only be `*` | / | INT64 | -| MAX_BY | MAX_BY(x, y) returns the value of x corresponding to the maximum value of the input y. MAX_BY(time, x) returns the timestamp when x is at its maximum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | / | Consistent with the data type of the first input x. | -| MIN_BY | MIN_BY(x, y) returns the value of x corresponding to the minimum value of the input y. MIN_BY(time, x) returns the timestamp when x is at its minimum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | / | Consistent with the data type of the first input x. | ## COUNT @@ -292,101 +290,4 @@ Result > 1. The parameter in count_time can only be *. > 2. Count_time aggregation cannot be used with other aggregation functions. > 3. Count_time aggregation used with having statement is not supported, and count_time aggregation can not appear in the having statement. -> 4. Count_time does not support use with group by level, group by tag. - - -### MAX_BY -#### Function Definition -max_by(x, y): Returns the value of x at the timestamp when y is at its maximum. -- max_by must have two input parameters x and y. -- Both x and y can use the keyword time, with max_by(time, x) returning the timestamp when x is at its maximum value. -- If x is null at the timestamp corresponding to the maximum value of y, null is returned. -- If y reaches its maximum value at multiple timestamps, the x value corresponding to the smallest timestamp among those maximum values is returned. -- Consistent with IoTDB max_value, only INT32, INT64, FLOAT, DOUBLE are supported as inputs for y, while all six types are supported as inputs for x. -- Direct numerical values are not allowed as inputs for either x or y. - -#### Grammar -```sql -select max_by(x, y) from root.sg -select max_by(time, x) from root.sg -``` - -#### Examples - -##### Input Data -```sql -IoTDB> select * from root.test -+-----------------------------+-----------+-----------+ -| Time|root.test.a|root.test.b| -+-----------------------------+-----------+-----------+ -|1970-01-01T08:00:00.001+08:00| 1.0| 10.0| -|1970-01-01T08:00:00.002+08:00| 2.0| 10.0| -|1970-01-01T08:00:00.003+08:00| 3.0| 10.0| -|1970-01-01T08:00:00.004+08:00| 10.0| 10.0| -|1970-01-01T08:00:00.005+08:00| 10.0| 12.0| -|1970-01-01T08:00:00.006+08:00| 6.0| 6.0| -+-----------------------------+-----------+-----------+ -``` -##### Query Example -Querying the timestamp corresponding to the maximum value: -```sql -IoTDB> select max_by(time, a), max_value(a) from root.test -+-------------------------+------------------------+ -|max_by(Time, root.test.a)| max_value(root.test.a)| -+-------------------------+------------------------+ -| 4| 10.0| -+-------------------------+------------------------+ -``` - -Finding the value of b when a is at its maximum: -```sql -IoTDB> select max_by(b, a) from root.test -+--------------------------------+ -|max_by(root.test.b, root.test.a)| -+--------------------------------+ -| 10.0| -+--------------------------------+ -``` - -Using with expressions: -```sql -IoTDB> select max_by(b + 1, a * 2) from root.test -+----------------------------------------+ -|max_by(root.test.b + 1, root.test.a * 2)| -+----------------------------------------+ -| 11.0| -+----------------------------------------+ -``` - -Using with group by clause： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.000+08:00| 3.0| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -``` - -Using with having clause： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) having max_by(b, a) > 4.0 -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -``` -Using with order by clause： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) order by time desc -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.000+08:00| 3.0| -+-----------------------------+--------------------------------+ -``` \ No newline at end of file +> 4. Count_time does not support use with group by level, group by tag. \ No newline at end of file diff --git a/src/UserGuide/latest/User-Manual/Operator-and-Expression.md b/src/UserGuide/latest/User-Manual/Operator-and-Expression.md index 4ca8bf80..5d14be32 100644 --- a/src/UserGuide/latest/User-Manual/Operator-and-Expression.md +++ b/src/UserGuide/latest/User-Manual/Operator-and-Expression.md @@ -99,23 +99,21 @@ The built-in functions can be used in IoTDB without registration, and the functi ### Aggregate Functions -| Function Name | Description | Allowed Input Series Data Types | Required Attributes | Output Series Data Type | -|---------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| ------------------------------- | ------------------------------------------------------------ | ----------------------------------- | -| SUM | Summation. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | -| COUNT | Counts the number of data points. | All types | / | INT | -| AVG | Average. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | -| EXTREME | Finds the value with the largest absolute value. Returns a positive value if the maximum absolute value of positive and negative values is equal. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | -| MAX_VALUE | Find the maximum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | -| MIN_VALUE | Find the minimum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | -| FIRST_VALUE | Find the value with the smallest timestamp. | All data types | / | Consistent with input data type | -| LAST_VALUE | Find the value with the largest timestamp. | All data types | / | Consistent with input data type | -| MAX_TIME | Find the maximum timestamp. | All data Types | / | Timestamp | -| MIN_TIME | Find the minimum timestamp. | All data Types | / | Timestamp | -| COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 | -| TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 | +| Function Name | Description | Allowed Input Series Data Types | Required Attributes | Output Series Data Type | +| ------------- | ------------------------------------------------------------ | ------------------------------- | ------------------------------------------------------------ | ----------------------------------- | +| SUM | Summation. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | +| COUNT | Counts the number of data points. | All types | / | INT | +| AVG | Average. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | +| EXTREME | Finds the value with the largest absolute value. Returns a positive value if the maximum absolute value of positive and negative values is equal. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | +| MAX_VALUE | Find the maximum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | +| MIN_VALUE | Find the minimum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | +| FIRST_VALUE | Find the value with the smallest timestamp. | All data types | / | Consistent with input data type | +| LAST_VALUE | Find the value with the largest timestamp. | All data types | / | Consistent with input data type | +| MAX_TIME | Find the maximum timestamp. | All data Types | / | Timestamp | +| MIN_TIME | Find the minimum timestamp. | All data Types | / | Timestamp | +| COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 | +| TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 | | MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type | -| MAX_BY | MAX_BY(x, y) returns the value of x corresponding to the maximum value of the input y. MAX_BY(time, x) returns the timestamp when x is at its maximum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | Consistent with the data type of the first input x. | -| MIN_BY | MIN_BY(x, y) returns the value of x corresponding to the minimum value of the input y. MIN_BY(time, x) returns the timestamp when x is at its minimum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | Consistent with the data type of the first input x. | For details and examples, see the document [Aggregate Functions](../Operators-Functions/Aggregation.md). diff --git a/src/UserGuide/latest/stage/Operators-Functions/Aggregation.md b/src/UserGuide/latest/stage/Operators-Functions/Aggregation.md index bf36b5b7..201fa0b3 100644 --- a/src/UserGuide/latest/stage/Operators-Functions/Aggregation.md +++ b/src/UserGuide/latest/stage/Operators-Functions/Aggregation.md @@ -27,24 +27,22 @@ All aggregate functions except `COUNT()`, `COUNT_IF()` ignore null values and re The aggregate functions supported by IoTDB are as follows: -| Function Name | Description | Allowed Input Series Data Types | Required Attributes | Output Series Data Type | -| ------------- | ------------------------------------------------------------ |-----------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------| -| SUM | Summation. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | -| COUNT | Counts the number of data points. | All data types | / | INT | -| AVG | Average. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | -| EXTREME | Finds the value with the largest absolute value. Returns a positive value if the maximum absolute value of positive and negative values is equal. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | -| MAX_VALUE | Find the maximum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | -| MIN_VALUE | Find the minimum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | -| FIRST_VALUE | Find the value with the smallest timestamp. | All data types | / | Consistent with input data type | -| LAST_VALUE | Find the value with the largest timestamp. | All data types | / | Consistent with input data type | -| MAX_TIME | Find the maximum timestamp. | All data Types | / | Timestamp | -| MIN_TIME | Find the minimum timestamp. | All data Types | / | Timestamp | -| COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 | -| TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 | -| MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type | -| COUNT_TIME | The number of timestamps in the query data set. When used with `align by device`, the result is the number of timestamps in the data set per device. | All data Types, the input parameter can only be `*` | / | INT64 | -| MAX_BY | MAX_BY(x, y) returns the value of x corresponding to the maximum value of the input y. MAX_BY(time, x) returns the timestamp when x is at its maximum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | / | Consistent with the data type of the first input x. | -| MIN_BY | MIN_BY(x, y) returns the value of x corresponding to the minimum value of the input y. MIN_BY(time, x) returns the timestamp when x is at its minimum value. | The first input x can be of any type, while the second input y must be of type INT32, INT64, FLOAT, or DOUBLE. | / | Consistent with the data type of the first input x. | +| Function Name | Description | Allowed Input Series Data Types | Required Attributes | Output Series Data Type | +| ------------- | ------------------------------------------------------------ |-----------------------------------------------------| ------------------------------------------------------------ | ----------------------------------- | +| SUM | Summation. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | +| COUNT | Counts the number of data points. | All data types | / | INT | +| AVG | Average. | INT32 INT64 FLOAT DOUBLE | / | DOUBLE | +| EXTREME | Finds the value with the largest absolute value. Returns a positive value if the maximum absolute value of positive and negative values is equal. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | +| MAX_VALUE | Find the maximum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | +| MIN_VALUE | Find the minimum value. | INT32 INT64 FLOAT DOUBLE | / | Consistent with the input data type | +| FIRST_VALUE | Find the value with the smallest timestamp. | All data types | / | Consistent with input data type | +| LAST_VALUE | Find the value with the largest timestamp. | All data types | / | Consistent with input data type | +| MAX_TIME | Find the maximum timestamp. | All data Types | / | Timestamp | +| MIN_TIME | Find the minimum timestamp. | All data Types | / | Timestamp | +| COUNT_IF | Find the number of data points that continuously meet a given condition and the number of data points that meet the condition (represented by keep) meet the specified threshold. | BOOLEAN | `[keep >=/>/=/!=/= threshold` if `threshold` is used alone, type of `threshold` is `INT64` `ignoreNull`：Optional, default value is `true`；If the value is `true`, null values are ignored, it means that if there is a null value in the middle, the value is ignored without interrupting the continuity. If the value is `true`, null values are not ignored, it means that if there are null values in the middle, continuity will be broken | INT64 | +| TIME_DURATION | Find the difference between the timestamp of the largest non-null value and the timestamp of the smallest non-null value in a column | All data Types | / | INT64 | +| MODE | Find the mode. Note: 1.Having too many different values in the input series risks a memory exception; 2.If all the elements have the same number of occurrences, that is no Mode, return the value with earliest time; 3.If there are many Modes, return the Mode with earliest time. | All data Types | / | Consistent with the input data type | +| COUNT_TIME | The number of timestamps in the query data set. When used with `align by device`, the result is the number of timestamps in the data set per device. | All data Types, the input parameter can only be `*` | / | INT64 | ## COUNT @@ -292,101 +290,4 @@ Result > 1. The parameter in count_time can only be *. > 2. Count_time aggregation cannot be used with other aggregation functions. > 3. Count_time aggregation used with having statement is not supported, and count_time aggregation can not appear in the having statement. -> 4. Count_time does not support use with group by level, group by tag. - - -### MAX_BY -#### Function Definition -max_by(x, y): Returns the value of x at the timestamp when y is at its maximum. -- max_by must have two input parameters x and y. -- Both x and y can use the keyword time, with max_by(time, x) returning the timestamp when x is at its maximum value. -- If x is null at the timestamp corresponding to the maximum value of y, null is returned. -- If y reaches its maximum value at multiple timestamps, the x value corresponding to the smallest timestamp among those maximum values is returned. -- Consistent with IoTDB max_value, only INT32, INT64, FLOAT, DOUBLE are supported as inputs for y, while all six types are supported as inputs for x. -- Direct numerical values are not allowed as inputs for either x or y. - -#### Grammar -```sql -select max_by(x, y) from root.sg -select max_by(time, x) from root.sg -``` - -#### Examples - -##### Input Data -```sql -IoTDB> select * from root.test -+-----------------------------+-----------+-----------+ -| Time|root.test.a|root.test.b| -+-----------------------------+-----------+-----------+ -|1970-01-01T08:00:00.001+08:00| 1.0| 10.0| -|1970-01-01T08:00:00.002+08:00| 2.0| 10.0| -|1970-01-01T08:00:00.003+08:00| 3.0| 10.0| -|1970-01-01T08:00:00.004+08:00| 10.0| 10.0| -|1970-01-01T08:00:00.005+08:00| 10.0| 12.0| -|1970-01-01T08:00:00.006+08:00| 6.0| 6.0| -+-----------------------------+-----------+-----------+ -``` -##### Query Example -Querying the timestamp corresponding to the maximum value: -```sql -IoTDB> select max_by(time, a), max_value(a) from root.test -+-------------------------+------------------------+ -|max_by(Time, root.test.a)| max_value(root.test.a)| -+-------------------------+------------------------+ -| 4| 10.0| -+-------------------------+------------------------+ -``` - -Finding the value of b when a is at its maximum: -```sql -IoTDB> select max_by(b, a) from root.test -+--------------------------------+ -|max_by(root.test.b, root.test.a)| -+--------------------------------+ -| 10.0| -+--------------------------------+ -``` - -Using with expressions: -```sql -IoTDB> select max_by(b + 1, a * 2) from root.test -+----------------------------------------+ -|max_by(root.test.b + 1, root.test.a * 2)| -+----------------------------------------+ -| 11.0| -+----------------------------------------+ -``` - -Using with group by clause： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.000+08:00| 3.0| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -``` - -Using with having clause： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) having max_by(b, a) > 4.0 -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -``` -Using with order by clause： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) order by time desc -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.000+08:00| 3.0| -+-----------------------------+--------------------------------+ -``` \ No newline at end of file +> 4. Count_time does not support use with group by level, group by tag. \ No newline at end of file diff --git a/src/zh/UserGuide/Master/Reference/Function-and-Expression.md b/src/zh/UserGuide/Master/Reference/Function-and-Expression.md index 65f16805..6b126e5c 100644 --- a/src/zh/UserGuide/Master/Reference/Function-and-Expression.md +++ b/src/zh/UserGuide/Master/Reference/Function-and-Expression.md @@ -29,24 +29,22 @@ IoTDB 支持的聚合函数如下： -| 函数名 | 功能描述 | 允许的输入类型 | 必要的属性参数 | 输出类型 | -|---------------|----------------------------------------------------------------------------------------------------------|-------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------| -| SUM | 求和。 | INT32 INT64 FLOAT DOUBLE | 无 | DOUBLE | -| COUNT | 计算数据点数。 | 所有类型 | 无 | INT64 | -| AVG | 求平均值。 | INT32 INT64 FLOAT DOUBLE | 无 | DOUBLE | -| EXTREME | 求具有最大绝对值的值。如果正值和负值的最大绝对值相等，则返回正值。 | INT32 INT64 FLOAT DOUBLE | 无 | 与输入类型一致 | -| MAX_VALUE | 求最大值。 | INT32 INT64 FLOAT DOUBLE | 无 | 与输入类型一致 | -| MIN_VALUE | 求最小值。 | INT32 INT64 FLOAT DOUBLE | 无 | 与输入类型一致 | -| FIRST_VALUE | 求时间戳最小的值。 | 所有类型 | 无 | 与输入类型一致 | -| LAST_VALUE | 求时间戳最大的值。 | 所有类型 | 无 | 与输入类型一致 | -| MAX_TIME | 求最大时间戳。 | 所有类型 | 无 | Timestamp | -| MIN_TIME | 求最小时间戳。 | 所有类型 | 无 | Timestamp | -| COUNT_IF | 求数据点连续满足某一给定条件，且满足条件的数据点个数（用keep表示）满足指定阈值的次数。 | BOOLEAN | `[keep >=/>/=/!=/= threshold`,`threshold`类型为`INT64`
`ignoreNull`：可选，默认为`true`；为`true`表示忽略null值，即如果中间出现null值，直接忽略，不会打断连续性；为`false`表示不忽略null值，即如果中间出现null值，会打断连续性 | INT64 | -| TIME_DURATION | 求某一列最大一个不为NULL的值所在时间戳与最小一个不为NULL的值所在时间戳的时间戳差 | 所有类型 | 无 | INT64 | -| MODE | 求众数。注意：
1.输入序列的不同值个数过多时会有内存异常风险;
2.如果所有元素出现的频次相同，即没有众数，则返回对应时间戳最小的值;
3.如果有多个众数，则返回对应时间戳最小的众数。 | 所有类型 | 无 | 与输入类型一致 | -| COUNT_TIME | 查询结果集的时间戳的数量。与 align by device 搭配使用时，得到的结果是每个设备的结果集的时间戳的数量。 | 所有类型，输入参数只能为* | 无 | INT64 | -| MAX_BY | MAX_BY(x, y) 求二元输入 x 和 y 在 y 最大时对应的 x 的值。MAX_BY(time, x) 返回 x 取最大值时对应的时间戳。 | 第一个输入 x 可以是任意类型，第二个输入 y 只能是 INT32 INT64 FLOAT DOUBLE | 无 | 与第一个输入 x 的数据类型一致 | -| MIN_BY | MIN_BY(x, y) 求二元输入 x 和 y 在 y 最小时对应的 x 的值。MIN_BY(time, x) 返回 x 取最小值时对应的时间戳。 | 第一个输入 x 可以是任意类型，第二个输入 y 只能是 INT32 INT64 FLOAT DOUBLE | 无 | 与第一个输入 x 的数据类型一致 | +| 函数名 | 功能描述 | 允许的输入类型 | 必要的属性参数 | 输出类型 | +|---------------|----------------------------------------------------------------------------------------------------------|--------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------| +| SUM | 求和。 | INT32 INT64 FLOAT DOUBLE | 无 | DOUBLE | +| COUNT | 计算数据点数。 | 所有类型 | 无 | INT64 | +| AVG | 求平均值。 | INT32 INT64 FLOAT DOUBLE | 无 | DOUBLE | +| EXTREME | 求具有最大绝对值的值。如果正值和负值的最大绝对值相等，则返回正值。 | INT32 INT64 FLOAT DOUBLE | 无 | 与输入类型一致 | +| MAX_VALUE | 求最大值。 | INT32 INT64 FLOAT DOUBLE | 无 | 与输入类型一致 | +| MIN_VALUE | 求最小值。 | INT32 INT64 FLOAT DOUBLE | 无 | 与输入类型一致 | +| FIRST_VALUE | 求时间戳最小的值。 | 所有类型 | 无 | 与输入类型一致 | +| LAST_VALUE | 求时间戳最大的值。 | 所有类型 | 无 | 与输入类型一致 | +| MAX_TIME | 求最大时间戳。 | 所有类型 | 无 | Timestamp | +| MIN_TIME | 求最小时间戳。 | 所有类型 | 无 | Timestamp | +| COUNT_IF | 求数据点连续满足某一给定条件，且满足条件的数据点个数（用keep表示）满足指定阈值的次数。 | BOOLEAN | `[keep >=/>/=/!=/= threshold`,`threshold`类型为`INT64`
`ignoreNull`：可选，默认为`true`；为`true`表示忽略null值，即如果中间出现null值，直接忽略，不会打断连续性；为`false`表示不忽略null值，即如果中间出现null值，会打断连续性 | INT64 | +| TIME_DURATION | 求某一列最大一个不为NULL的值所在时间戳与最小一个不为NULL的值所在时间戳的时间戳差 | 所有类型 | 无 | INT64 | +| MODE | 求众数。注意：
1.输入序列的不同值个数过多时会有内存异常风险;
2.如果所有元素出现的频次相同，即没有众数，则返回对应时间戳最小的值;
3.如果有多个众数，则返回对应时间戳最小的众数。 | 所有类型 | 无 | 与输入类型一致 | +| COUNT_TIME | 查询结果集的时间戳的数量。与 align by device 搭配使用时，得到的结果是每个设备的结果集的时间戳的数量。 | 所有类型，输入参数只能为* | 无 | INT64 | ### COUNT_IF @@ -278,107 +276,6 @@ select count_time(*) from root.db.** group by([0, 10), 2ms) align by device > 3. having语句里不支持使用count_time, 使用count_time聚合函数时不支持使用having语句。 > 4. count_time不支持与group by level, group by tag一起使用。 - - -### MAX_BY - -#### 功能定义 -max_by(x, y)： 返回 y 最大时对应时间戳下的 x 值。 - - max_by 必须有两个输入参数 x 和 y。 - - x 和 y 均可以为 time 关键字, max_by(time, x) 返回 x 取最大值时对应的时间戳。 - - 如果 y 最大时对应的时间戳下 x 为 null，则返回 null。 - - 如果 y 可以在多个时间戳下取得最大值，取最大值中最小时间戳对应的 x 值。 - - 与 IoTDB max_value 保持一致，仅支持 INT32、INT64、FLOAT、DOUBLE 作为 y 的输入，支持所有六种类型作为 x 的输入。 - - x, y 的输入均不允许为具体数值。 - - -#### 语法 -```sql -select max_by(x, y) from root.sg -select max_by(time, x) from root.sg -``` - -#### 使用示例 - -##### 原始数据 -```sql -IoTDB> select * from root.test -+-----------------------------+-----------+-----------+ -| Time|root.test.a|root.test.b| -+-----------------------------+-----------+-----------+ -|1970-01-01T08:00:00.001+08:00| 1.0| 10.0| -|1970-01-01T08:00:00.002+08:00| 2.0| 10.0| -|1970-01-01T08:00:00.003+08:00| 3.0| 10.0| -|1970-01-01T08:00:00.004+08:00| 10.0| 10.0| -|1970-01-01T08:00:00.005+08:00| 10.0| 12.0| -|1970-01-01T08:00:00.006+08:00| 6.0| 6.0| -+-----------------------------+-----------+-----------+ -``` -##### 查询示例 -查询最大值对应的时间戳： -```sql -IoTDB> select max_by(time, a), max_value(a) from root.test -+-------------------------+------------------------+ -|max_by(Time, root.test.a)| max_value(root.test.a)| -+-------------------------+------------------------+ -| 4| 10.0| -+-------------------------+------------------------+ -``` - -求 a 最大时对应的 b 值： -```sql -IoTDB> select max_by(b, a) from root.test -+--------------------------------+ -|max_by(root.test.b, root.test.a)| -+--------------------------------+ -| 10.0| -+--------------------------------+ -``` - -结合表达式使用： -```sql -IoTDB> select max_by(b + 1, a * 2) from root.test -+----------------------------------------+ -|max_by(root.test.b + 1, root.test.a * 2)| -+----------------------------------------+ -| 11.0| -+----------------------------------------+ -``` - -结合 group by time 子句使用： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.000+08:00| 3.0| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -``` - -结合 having 子句使用： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) having max_by(b, a) > 4.0 -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -``` -结合 order by 子句使用： -```sql -IoTDB> select max_by(b, a) from root.test group by ([0,7),4ms) order by time desc -+-----------------------------+--------------------------------+ -| Time|max_by(root.test.b, root.test.a)| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.004+08:00| 10.0| -+-----------------------------+--------------------------------+ -|1970-01-01T08:00:00.000+08:00| 3.0| -+-----------------------------+--------------------------------+ -``` - -