Merge pull request #750 from malongcn/develop
时间维度聚合的实例中 group by和fill 顺序写反了
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d5433a8172
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@ -359,9 +359,9 @@ SELECT function_list FROM tb_name
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SELECT function_list FROM stb_name
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[WHERE where_condition]
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[GROUP BY tags]
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[FILL ({ VALUE | PREV | NULL | LINEAR})]
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INTERVAL (interval)
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[FILL ({ VALUE | PREV | NULL | LINEAR})]</code></pre>
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[GROUP BY tags]</code></pre>
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<ul>
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<li>聚合时间段的长度由关键词INTERVAL指定,最短时间间隔10毫秒(10a)。聚合查询中,能够同时执行的聚合和选择函数仅限于单个输出的函数:count、avg、sum 、stddev、leastsquares、percentile、min、max、first、last,不能使用具有多行输出结果的函数(例如:top、bottom、diff以及四则运算)。</li>
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<li>WHERE语句可以指定查询的起止时间和其他过滤条件 </li>
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@ -54,7 +54,7 @@ STable从属于库,一个STable只属于一个库,但一个库可以有一
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说明:
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1. TAGS列总长度不能超过512 bytes;
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2. TAGS列的数据类型不能是timestamp和nchar类型;
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2. TAGS列的数据类型不能是timestamp;
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3. TAGS列名不能与其他列名相同;
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4. TAGS列名不能为预留关键字.
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@ -218,7 +218,7 @@ GROUP BY location, type
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```mysql
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SELECT COUNT(*), AVG(degree), MAX(degree), MIN(degree)
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FROM thermometer
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WHERE name<>'beijing' and ts>=now-1d
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WHERE location<>'beijing' and ts>=now-1d
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INTERVAL(10M)
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GROUP BY location, type
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```
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@ -23,7 +23,7 @@ New keyword "tags" is introduced, where tag_name is the tag name, and tag_type i
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Note:
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1. The bytes of all tags together shall be less than 512
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2. Tag's data type can not be time stamp or nchar
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2. Tag's data type can not be time stamp
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3. Tag name shall be different from the field name
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4. Tag name shall not be the same as system keywords
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5. Maximum number of tags is 6
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@ -102,7 +102,7 @@ List the number of records, average, maximum, and minimum temperature every 10 m
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```mysql
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SELECT COUNT(*), AVG(degree), MAX(degree), MIN(degree)
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FROM thermometer
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WHERE name='beijing' and type=10 and ts>=now-1d
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WHERE location='beijing' and type=10 and ts>=now-1d
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INTERVAL(10M)
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```
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@ -424,9 +424,9 @@ SELECT function_list FROM tb_name
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SELECT function_list FROM stb_name
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[WHERE where_condition]
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[GROUP BY tags]
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INTERVAL (interval)
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[FILL ({ VALUE | PREV | NULL | LINEAR})]
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[GROUP BY tags]
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```
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- 聚合时间段的长度由关键词INTERVAL指定,最短时间间隔10毫秒(10a)。聚合查询中,能够同时执行的聚合和选择函数仅限于单个输出的函数:count、avg、sum 、stddev、leastsquares、percentile、min、max、first、last,不能使用具有多行输出结果的函数(例如:top、bottom、diff以及四则运算)。
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@ -474,9 +474,9 @@ SELECT function_list FROM tb_name
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SELECT function_list FROM stb_name
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[WHERE where_condition]
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[GROUP BY tags]
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INTERVAL (interval)
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[FILL ({ VALUE | PREV | NULL | LINEAR})]
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[GROUP BY tags]
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```
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The downsampling time window is defined by `interval`, which is at least 10 milliseconds. The query returns a new series of downsampled data that has a series of fixed timestamps with an increment of `interval`.
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