|
| 1 | +# 客户端基本操作 |
| 2 | + |
| 3 | +## 0 clickhouse-client |
| 4 | + |
| 5 | +一个原生的、基于TCP协议的命令行客户端。支持两种使用方式: |
| 6 | + |
| 7 | +- 交互式模式 |
| 8 | + |
| 9 | +- 非交互式模式(批模式) |
| 10 | + |
| 11 | + 通过--query参数执行数据的查询、插入等操作,执行完成后退出。非交互式模式下默认数据格式为TabSeparated(制表符),可用FORMAT指定格式 |
| 12 | + |
| 13 | +ClickHouse 数据库的命令行客户端工具。它允许用户通过命令行界面与 ClickHouse 交互。 |
| 14 | + |
| 15 | +## 1 登录 |
| 16 | + |
| 17 | +```bash |
| 18 | +[root@javaedge-clickhouse-test bin]# clickhouse-client --user default --password xxxxxx |
| 19 | +ClickHouse client version 22.9.3.18 (official build). |
| 20 | +Connecting to localhost:9000 as user default. |
| 21 | +Connected to ClickHouse server version 22.9.3 revision 54460. |
| 22 | + |
| 23 | +Warnings: |
| 24 | + * Linux transparent hugepages are set to "always". Check /sys/kernel/mm/transparent_hugepage/enabled |
| 25 | + |
| 26 | +javaedge-clickhouse-test :) |
| 27 | +``` |
| 28 | + |
| 29 | +可见,默认 9000 端口(可改)。 |
| 30 | + |
| 31 | +## 2 建表 |
| 32 | + |
| 33 | +```bash |
| 34 | +CREATE TABLE my_first_table |
| 35 | + ( |
| 36 | + user_id UInt32, |
| 37 | + message String, |
| 38 | + timestamp DateTime, |
| 39 | + metric Float32 |
| 40 | + ) |
| 41 | + ENGINE = MergeTree |
| 42 | + PRIMARY KEY (user_id, timestamp) |
| 43 | + |
| 44 | +CREATE TABLE my_first_table |
| 45 | +( |
| 46 | + `user_id` UInt32, |
| 47 | + `message` String, |
| 48 | + `timestamp` DateTime, |
| 49 | + `metric` Float32 |
| 50 | +) |
| 51 | +ENGINE = MergeTree |
| 52 | +PRIMARY KEY (user_id, timestamp) |
| 53 | + |
| 54 | +Query id: f96df3f3-8fb6-4f6e-a959-e18c151599c6 |
| 55 | + |
| 56 | +Ok. |
| 57 | + |
| 58 | +0 rows in set. Elapsed: 0.008 sec. |
| 59 | + |
| 60 | +javaedge-clickhouse-test :) |
| 61 | +``` |
| 62 | + |
| 63 | +使用CREATE TABLE定义一个新表。在ClickHouse中,通常的SQL DDL命令可以使用,只是需要加上ENGINE子句来指定表的引擎。使用MergeTree可充分利用ck的性能优势。 |
| 64 | + |
| 65 | +## 3 新增数据 |
| 66 | + |
| 67 | +可使用熟悉的INSERT INTO TABLE命令,但重要的是要理解,每次向MergeTree表插入数据都会在存储中创建一个**part**(文件夹)。为减少**part**的数量,建议一次性批量插入大量行(数万甚至数百万行)。 |
| 68 | + |
| 69 | +```bash |
| 70 | +INSERT INTO my_first_table (user_id, message, timestamp, metric) VALUES |
| 71 | + (101, 'Hello, ClickHouse!', now(), -1.0 ), |
| 72 | + (102, 'Insert a lot of rows per batch', yesterday(), 1.41421 ), |
| 73 | + (102, 'Sort your data based on your commonly-used queries', today(), 2.718 ), |
| 74 | + (101, 'Granules are the smallest chunks of data read', now() + 5, 3.14159 ) |
| 75 | + |
| 76 | +INSERT INTO my_first_table (user_id, message, timestamp, metric) FORMAT Values |
| 77 | + |
| 78 | +Query id: 46944361-de07-4b72-ac8c-61aa9fecb85d |
| 79 | + |
| 80 | +Ok. |
| 81 | + |
| 82 | +4 rows in set. Elapsed: 0.005 sec. |
| 83 | + |
| 84 | +javaedge-clickhouse-test :) |
| 85 | +``` |
| 86 | +
|
| 87 | +## 4 查询 |
| 88 | +
|
| 89 | +像常规SQL一样编写SELECT查询: |
| 90 | +
|
| 91 | +```sql |
| 92 | + SELECT * |
| 93 | + FROM my_first_table |
| 94 | + ORDER BY timestamp |
| 95 | +``` |
| 96 | +
|
| 97 | +响应表格: |
| 98 | +
|
| 99 | +```sql |
| 100 | +┌─user_id─┬─message────────────────────────────────────────────┬───────────timestamp─┬──metric─┐ |
| 101 | +│ 102 │ Insert a lot of rows per batch │ 2022-03-21 00:00:00 │ 1.41421 │ |
| 102 | +│ 102 │ Sort your data based on your commonly-used queries │ 2022-03-22 00:00:00 │ 2.718 │ |
| 103 | +│ 101 │ Hello, ClickHouse! │ 2022-03-22 14:04:09 │ -1 │ |
| 104 | +│ 101 │ Granules are the smallest chunks of data read │ 2022-03-22 14:04:14 │ 3.14159 │ |
| 105 | +└─────────┴────────────────────────────────────────────────────┴─────────────────────┴─────────┘ |
| 106 | + |
| 107 | +4 rows in set. Elapsed: 0.008 sec. |
| 108 | +``` |
| 109 | +
|
| 110 | +下一步是将你的现有数据导入ClickHouse。有许多表函数和集成可用于摄入数据。 |
| 111 | +
|
| 112 | +自定义查询格式: |
| 113 | +
|
| 114 | +```sql |
| 115 | +SELECT * |
| 116 | +FROM |
| 117 | + mysql( |
| 118 | + 'localhost:3306', |
| 119 | + 'my_database', |
| 120 | + 'my_table', |
| 121 | + 'postgresql_user', |
| 122 | + 'password') |
| 123 | +; |
| 124 | +``` |
| 125 | +
|
| 126 | +### 指定参数 |
| 127 | +
|
| 128 | +查询参数格式: |
| 129 | +
|
| 130 | +```bash |
| 131 | +{<name>:<data type>} |
| 132 | +``` |
| 133 | +
|
| 134 | +- name为参数名称 |
| 135 | +- data type为数据类型 |
| 136 | +
|
| 137 | +如:{parName:Array(Unt16)} |
| 138 | +
|
| 139 | +参数值通过命令行参数指定,格式: |
| 140 | +
|
| 141 | +```bash |
| 142 | +param_<name> = value |
| 143 | +``` |
| 144 | +
|
| 145 | +
|
| 146 | +
|
| 147 | +```bash |
| 148 | +clickhouse-client --param_myid=3 -q "SELECT * FROM table WHERE a = {myid:Ulnt8}" |
| 149 | +``` |
| 150 | +
|
| 151 | +## 5 其它 |
| 152 | +
|
| 153 | +历史的执行语句保存在操作系统文件 |
| 154 | +
|
| 155 | +```sql |
| 156 | +# 隐藏文件 |
| 157 | +[root@clickhouse-test bin]# ll ~/.clickhouse-client-history |
| 158 | +-rw------- 1 root root 6100 Feb 18 13:34 /root/.clickhouse-client-history |
| 159 | + |
| 160 | +# more |
| 161 | +CREATE TABLE default.local( ptcId String, ptcType String, dataSource String, deviceIdList String, timestamp |
| 162 | +String, lat String, lon String, region String, nodeId String, linkName String, posConfid String, heading String, motionCo |
| 163 | +nfid String, accelerationConfid String, width String, length String, height String, vehicleType String, ptcSizeConfid String, |
| 164 | + ptcTypeEx String)ENGINE = MergeTree()ORDER BY (ptcId, timestamp)SETTINGS index_granularity = 8192; |
| 165 | +``` |
| 166 | +
|
| 167 | +退出客户端的方式: |
| 168 | +
|
| 169 | +- 按Ctrl + D或Ctrl+℃ |
| 170 | +- 或执行命令exit、quit、logout、q、Q、:q |
| 171 | +
|
| 172 | +## 6 设置参数的方式 |
| 173 | +
|
| 174 | +- 命令行设置:通过命令行的选项设置参数 |
| 175 | +- 配置文件:在配置文件配置参数。命令行参数优先级高于配置文件参数 |
| 176 | +
|
| 177 | +clickhouse-client常用参数: |
| 178 | +
|
| 179 | +- --host,-h:主机名,默认为localhost |
| 180 | +- --port:TCP端口,默认为9000 |
| 181 | +- `--user/-u default` :使用默认用户名进行登录 |
| 182 | +- `--password xxxxxx` :使用指定的密码进行身份验证。将 `xxxxxx` 替换为实际密码 |
| 183 | +- --query,-q: 查询语句,在非交互式模式下使用 |
| 184 | +- --queries-file,-qf:查询语句的文件路径 |
| 185 | +- --multiline,-m:编写SQL语句,支持换行 |
| 186 | +- --multiquery,-n:同时执行多个查询,查询语句使用分号分隔 |
| 187 | +
|
| 188 | +### 通过配置文件传递参数 |
| 189 | +
|
| 190 | +clickhouse-client按顺序,使用如下第一个出现的配置文件: |
| 191 | +
|
| 192 | +- 通过--config-file参数指定的配置文件 |
| 193 | +- ./clickhouse-client.xml |
| 194 | +- ~/.clickhouse-client/config.xml |
| 195 | +- /etc/clickhouse-client/config.xml |
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