IoTDB 入门教程 基础篇⑥——数据库SQL操作 | 数据库管理和数据读写_iotdb sql

一、前文

IoTDB入门教程——导读

本博文主要讲述数据库管理和数据读写

二、数据库管理

2.1 创建数据库

CREATE DATABASE root.ln

IoTDB> CREATE DATABASE root.test
Msg: The statement is executed successfully.
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注意：必须是root.开头

这一点也是我一直吐槽的地方，为啥要限制必须root.开头呢？

全部都是root.开头不就等于全部都没有root.开头。意义何在呢。

IoTDB> CREATE DATABASE test
Msg: org.apache.iotdb.jdbc.IoTDBSQLException: 700: Error occurred while parsing SQL to physical plan: line 1:16 mismatched input 'test' expecting ROOT
IoTDB> CREATE DATABASE test.test
Msg: org.apache.iotdb.jdbc.IoTDBSQLException: 700: Error occurred while parsing SQL to physical plan: line 1:16 mismatched input 'test' expecting ROOT
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注意：Database的父子节点都不能再设置 database

IoTDB> CREATE DATABASE root.test.aa
Msg: org.apache.iotdb.jdbc.IoTDBSQLException: 501: root.test has already been created as database
IoTDB> CREATE DATABASE root.test1.aa
Msg: The statement is executed successfully.
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2.2 查询数据库

SHOW DATABASES;

IoTDB> SHOW DATABASES;
+----------------+----+-----------------------+---------------------+---------------------+
|        Database| TTL|SchemaReplicationFactor|DataReplicationFactor|TimePartitionInterval|
+----------------+----+-----------------------+---------------------+---------------------+
|      root.user1|null|                      1|                    1|            604800000|
|   root.test1.aa|null|                      1|                    1|            604800000|
|       root.test|null|                      1|                    1|            604800000|
|root.water_meter|null|                      1|                    1|            604800000|
+----------------+----+-----------------------+---------------------+---------------------+
Total line number = 4
It costs 0.010s
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2.3 删除数据库

DELETE DATABASE root.ln

IoTDB> DELETE DATABASE root.user1
Msg: The statement is executed successfully.
IoTDB> SHOW DATABASES;
+----------------+----+-----------------------+---------------------+---------------------+
|        Database| TTL|SchemaReplicationFactor|DataReplicationFactor|TimePartitionInterval|
+----------------+----+-----------------------+---------------------+---------------------+
|   root.test1.aa|null|                      1|                    1|            604800000|
|       root.test|null|                      1|                    1|            604800000|
|root.water_meter|null|                      1|                    1|            604800000|
+----------------+----+-----------------------+---------------------+---------------------+
Total line number = 3
It costs 0.006s
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IoTDB> DELETE DATABASE root.test1.aa
Msg: The statement is executed successfully.
IoTDB> SHOW DATABASES;
+----------------+----+-----------------------+---------------------+---------------------+
|        Database| TTL|SchemaReplicationFactor|DataReplicationFactor|TimePartitionInterval|
+----------------+----+-----------------------+---------------------+---------------------+
|       root.test|null|                      1|                    1|            604800000|
|root.water_meter|null|                      1|                    1|            604800000|
+----------------+----+-----------------------+---------------------+---------------------+
Total line number = 2
It costs 0.005s
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三、数据读写

3.1 查询数据

select status from root.test.test

IoTDB> select status from root.test.test
+-----------------------------+---------------------+
|                         Time|root.test.test.status|
+-----------------------------+---------------------+
|2024-05-03T19:18:07.573+08:00|                  1.0|
|2024-05-03T19:18:19.825+08:00|                  2.0|
|2024-05-03T19:18:21.893+08:00|                  3.0|
+-----------------------------+---------------------+
Total line number = 3
It costs 0.127s
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3.2 新增数据

• 新增单条数据

INSERT INTO root.test.test(status) values(1)

IoTDB> INSERT INTO root.test.test(status) values(1)
Msg: The statement is executed successfully.
IoTDB> INSERT INTO root.test.test(status) values(2)
Msg: The statement is executed successfully.
IoTDB> INSERT INTO root.test.test(status) values(3)
Msg: The statement is executed successfully.
IoTDB> select status from root.test.test
+-----------------------------+---------------------+
|                         Time|root.test.test.status|
+-----------------------------+---------------------+
|2024-05-03T19:18:07.573+08:00|                  1.0|
|2024-05-03T19:18:19.825+08:00|                  2.0|
|2024-05-03T19:18:21.893+08:00|                  3.0|
+-----------------------------+---------------------+
Total line number = 3
It costs 0.127s
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• 新增多条数据

注意：新增多条数据，需要传入时间戳参数

INSERT INTO root.test.test(timestamp,status) values(1,4),(2,5),(3,6)

IoTDB> INSERT INTO root.test.test(timestamp,status) values(1,4),(2,5),(3,6)
Msg: The statement is executed successfully.
IoTDB> select status from root.test.test
+-----------------------------+---------------------+
|                         Time|root.test.test.status|
+-----------------------------+---------------------+
|1970-01-01T08:00:00.001+08:00|                  4.0|
|1970-01-01T08:00:00.002+08:00|                  5.0|
|1970-01-01T08:00:00.003+08:00|                  6.0|
|2024-05-03T19:18:07.573+08:00|                  1.0|
|2024-05-03T19:18:19.825+08:00|                  2.0|
|2024-05-03T19:18:21.893+08:00|                  3.0|
+-----------------------------+---------------------+
Total line number = 6
It costs 0.012s
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3.3 修改数据

传入同样的时间戳，即可覆盖该时间戳的上一条数据

IoTDB> INSERT INTO root.test.test(timestamp,status) values(1,444)
Msg: The statement is executed successfully.
IoTDB> SELECT status FROM root.test.test
+-----------------------------+---------------------+
|                         Time|root.test.test.status|
+-----------------------------+---------------------+
|1970-01-01T08:00:00.001+08:00|                444.0|
|1970-01-01T08:00:00.002+08:00|                  5.0|
|1970-01-01T08:00:00.003+08:00|                  6.0|
|2024-05-03T19:18:07.573+08:00|                  1.0|
|2024-05-03T19:18:19.825+08:00|                  2.0|
|2024-05-03T19:18:21.893+08:00|                  3.0|
+-----------------------------+---------------------+
Total line number = 6
It costs 0.010s
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3.4 删除数据

DELETE FROM root.test.test.status where time < 4

IoTDB> DELETE FROM root.test.test.status where time < 4
Msg: The statement is executed successfully.
IoTDB> SELECT status FROM root.test.test
+-----------------------------+---------------------+
|                         Time|root.test.test.status|
+-----------------------------+---------------------+
|2024-05-03T19:18:07.573+08:00|                  1.0|
|2024-05-03T19:18:19.825+08:00|                  2.0|
|2024-05-03T19:18:21.893+08:00|                  3.0|
+-----------------------------+---------------------+
Total line number = 3
It costs 0.014s

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四、参考

SQL手册 | IoTDB Website

数据增删 | IoTDB Website

数据查询 | IoTDB Website

觉得好，就一键三连呗（点赞+收藏+关注）