1d9b3aeee7
The error format '##keyword' in a lot of docs. This pr is to repair document format. #4335
62 lines
1.5 KiB
Markdown
62 lines
1.5 KiB
Markdown
---
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{
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"title": "COUNT",
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"language": "en"
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}
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---
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<!--
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Licensed to the Apache Software Foundation (ASF) under one
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or more contributor license agreements. See the NOTICE file
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distributed with this work for additional information
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regarding copyright ownership. The ASF licenses this file
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to you under the Apache License, Version 2.0 (the
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"License"); you may not use this file except in compliance
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with the License. You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing,
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software distributed under the License is distributed on an
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"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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KIND, either express or implied. See the License for the
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specific language governing permissions and limitations
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under the License.
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-->
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# COUNT
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## Description
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### Syntax
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`COUNT([DISTINCT] expr)`
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Number of rows used to return the required rows
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## example
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```
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MySQL > select count(*) from log_statis group by datetime;
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+----------+
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| count(*) |
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+----------+
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| 28515903 |
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+----------+
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MySQL > select count(datetime) from log_statis group by datetime;
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+-------------------+
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| count(`datetime`) |
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+-------------------+
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| 28521682 |
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+-------------------+
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MySQL > select count(distinct datetime) from log_statis group by datetime;
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+-------------------------------+
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| count(DISTINCT `datetime`) |
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+-------------------------------+
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| 71045 |
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+-------------------------------+
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```
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## keyword
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COUNT
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