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# Data Addition & Deletion

## 1. Data Insertion

**Syntax:**

```SQL
INSERT INTO <TABLE_NAME> [(COLUMN_NAME[, COLUMN_NAME]*)]? VALUES (COLUMN_VALUE[, COLUMN_VALUE]*)
```

[Detailed syntax reference](../Basic-Concept/Write-Updata-Data_timecho.md#_1-1-syntax)

**Example 1: Specified Columns Insertion**

```SQL
INSERT INTO table1(region, plant_id, device_id, time, temperature, humidity) VALUES ('Hamburg', '1001', '100', '2025-11-26 13:37:00', 90.0, 35.1);

INSERT INTO table1(region, plant_id, device_id, time, temperature) VALUES ('Hamburg', '1001', '100', '2025-11-26 13:38:00', 91.0);
```

**Example 2: NULL Value Insertion**

Equivalent to the example above
```SQL
INSERT INTO table1(region, plant_id, device_id, model_id, maintenance, time, temperature, humidity) VALUES ('Hamburg', '1001', '100', null, null, '2025-11-26 13:37:00', 90.0, 35.1);

INSERT INTO table1(region, plant_id, device_id, model_id, maintenance, time, temperature, humidity) VALUES ('Hamburg', '1001', '100', null, null, '2025-11-26 13:38:00', 91.0, null);
```

**Example 3: Multi-row Insertion**

```SQL
INSERT INTO table1
VALUES 
('2025-11-26 13:37:00', 'Frankfurt', '1001', '100', 'A', '180', 90.0, 35.1, true, '2025-11-26 13:37:34'),
('2025-11-26 13:38:00', 'Frankfurt', '1001', '100', 'A', '180', 90.0, 35.1, true, '2025-11-26 13:38:25');

INSERT INTO table1
(region, plant_id, device_id, model_id, maintenance, time, temperature, humidity, status, arrival_time) 
VALUES 
('Frankfurt', '1001', '100', 'A', '180', '2025-11-26 13:37:00', 90.0, 35.1, true, '2025-11-26 13:37:34'),
('Frankfurt', '1001', '100', 'A', '180', '2025-11-26 13:38:00', 90.0, 35.1, true, '2025-11-26 13:38:25');
```

**Example 4: Query Write-back**

```SQL
insert into target_table select time,region,device_id,temperature from table1 where region = 'bj';

insert into target_table(time,device_id,temperature) table table3;

insert into target_table (select t1.time, t1.region as region, t1.device_id as device_id, t1.temperature as temperature from table1 t1 where t1.time in (select t2.time from table2 t2 where t2.region = 'shh'));
```


## 2. Data Update

**Syntax:**

```SQL
UPDATE <TABLE_NAME> SET updateAssignment (',' updateAssignment)* (WHERE where=booleanExpression)?

updateAssignment
    : identifier EQ expression
    ;
```

[Detailed syntax reference](../Basic-Concept/Write-Updata-Data_timecho.md#_2-1-syntax)

**Example:**

```SQL
update table1 set b = a where substring(a, 1, 1) like '%';
```

## 3. Data Deletion

**Syntax:**

```SQL
DELETE FROM <TABLE_NAME> [WHERE_CLAUSE]?

WHERE_CLAUSE:
    WHERE DELETE_CONDITION

DELETE_CONDITION:
    SINGLE_CONDITION
    | DELETE_CONDITION AND DELETE_CONDITION
    | DELETE_CONDITION OR DELETE_CONDITION

SINGLE_CODITION:
    TIME_CONDITION | ID_CONDITION

TIME_CONDITION:
    time TIME_OPERATOR LONG_LITERAL

TIME_OPERATOR:
    < | > | <= | >= | =

ID_CONDITION:
    identifier = STRING_LITERAL
```

**Example 1: Full Table Deletion**

```SQL
DELETE FROM table1;
```

**Example 2: Time-range Deletion**

Single time range
```SQL
DELETE FROM table1 WHERE time <= 2024-11-29 00:00:00;
```
Multiple time ranges
```sql
DELETE FROM table1  WHERE time >= 2024-11-27 00:00:00  and time <= 2024-11-29 00:00:00;
```

**Example 3: Device-Specific Deletion**

Delete data for specific device
```SQL
DELETE FROM table1 
WHERE device_id='101' AND model_id = 'B';
```
Delete data for device within time range
```sql
DELETE FROM table1 
WHERE time >= '2024-11-27 16:39:00' AND time <= '2024-11-29 16:42:00'
    AND device_id='101' AND model_id = 'B';
```    
Delete data for specific device model
```sql
DELETE FROM table1 WHERE model_id = 'B';
```

## 4. Device Deletion

**Syntax:**

```SQL
DELETE DEVICES FROM tableName=qualifiedName (WHERE booleanExpression)?
```

**Example: Delete specified device and all associated data**

```SQL
DELETE DEVICES FROM table1 WHERE device_id = '101';
```