mirror of
https://gitee.com/rulego/streamsql.git
synced 2026-04-14 08:08:16 +00:00
rulego-team
120 lines
3.7 KiB
Go
120 lines
3.7 KiB
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"time"
|
|
|
|
"github.com/rulego/streamsql"
|
|
"github.com/rulego/streamsql/functions"
|
|
"github.com/rulego/streamsql/utils/cast"
|
|
)
|
|
|
|
func main() {
|
|
fmt.Println("=== StreamSQL 高级函数示例 ===")
|
|
|
|
// 1. 注册自定义函数：温度华氏度转摄氏度
|
|
err := functions.RegisterCustomFunction("fahrenheit_to_celsius", functions.TypeCustom, "温度转换", "华氏度转摄氏度", 1, 1,
|
|
func(ctx *functions.FunctionContext, args []interface{}) (interface{}, error) {
|
|
fahrenheit, err := cast.ToFloat64E(args[0])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
celsius := (fahrenheit - 32) * 5 / 9
|
|
return celsius, nil
|
|
})
|
|
if err != nil {
|
|
panic(fmt.Sprintf("注册自定义函数失败: %v", err))
|
|
}
|
|
fmt.Println("✓ 注册自定义函数：fahrenheit_to_celsius")
|
|
|
|
// 2. 创建 StreamSQL 实例
|
|
ssql := streamsql.New()
|
|
defer ssql.Stop()
|
|
|
|
// 3. 定义包含高级函数的 SQL
|
|
sql := `
|
|
SELECT
|
|
device,
|
|
AVG(abs(temperature - 20)) as avg_deviation,
|
|
AVG(fahrenheit_to_celsius(temperature)) as avg_celsius,
|
|
MAX(sqrt(humidity)) as max_sqrt_humidity
|
|
FROM stream
|
|
GROUP BY device, TumblingWindow('2s')
|
|
WITH (TIMESTAMP='ts', TIMEUNIT='ss')
|
|
`
|
|
|
|
// 4. 执行 SQL
|
|
err = ssql.Execute(sql)
|
|
if err != nil {
|
|
panic(fmt.Sprintf("执行SQL失败: %v", err))
|
|
}
|
|
fmt.Println("✓ SQL执行成功")
|
|
|
|
// 5. 添加结果监听器
|
|
ssql.AddSink(func(result []map[string]interface{}) {
|
|
fmt.Printf("📊 聚合结果: %v\n", result)
|
|
})
|
|
|
|
// 6. 模拟传感器数据
|
|
baseTime := time.Now()
|
|
sensorData := []map[string]interface{}{
|
|
{"device": "sensor1", "temperature": 68.0, "humidity": 25.0, "ts": baseTime.UnixMicro()}, // 20°C, 湿度25%
|
|
{"device": "sensor1", "temperature": 86.0, "humidity": 36.0, "ts": baseTime.Unix()}, // 30°C, 湿度36%
|
|
{"device": "sensor2", "temperature": 32.0, "humidity": 49.0, "ts": baseTime.Unix()}, // 0°C, 湿度49%
|
|
{"device": "sensor2", "temperature": 104.0, "humidity": 64.0, "ts": baseTime.Unix()}, // 40°C, 湿度64%
|
|
{"device": "temperature_probe", "temperature": 212.0, "humidity": 81.0, "ts": baseTime.Unix()}, // 100°C, 湿度81%
|
|
}
|
|
|
|
fmt.Println("\n🌡️ 发送传感器数据:")
|
|
for _, data := range sensorData {
|
|
fmt.Printf(" 设备: %s, 温度: %.1f°F, 湿度: %.1f%%\n",
|
|
data["device"], data["temperature"], data["humidity"])
|
|
ssql.Emit(data)
|
|
}
|
|
|
|
// 7. 等待处理完成
|
|
fmt.Println("\n⏳ 等待窗口处理...")
|
|
time.Sleep(3 * time.Second)
|
|
|
|
// 8. 演示内置函数
|
|
fmt.Println("\n🔧 内置函数演示:")
|
|
|
|
// 数学函数
|
|
fmt.Printf(" abs(-15.5) = %.1f\n", callFunction("abs", -15.5))
|
|
fmt.Printf(" sqrt(16) = %.1f\n", callFunction("sqrt", 16.0))
|
|
|
|
// 字符串函数
|
|
fmt.Printf(" concat('Hello', ' ', 'World') = %s\n", callFunction("concat", "Hello", " ", "World"))
|
|
fmt.Printf(" upper('streamsql') = %s\n", callFunction("upper", "streamsql"))
|
|
fmt.Printf(" length('StreamSQL') = %d\n", callFunction("length", "StreamSQL"))
|
|
|
|
// 转换函数
|
|
fmt.Printf(" hex2dec('ff') = %d\n", callFunction("hex2dec", "ff"))
|
|
fmt.Printf(" dec2hex(255) = %s\n", callFunction("dec2hex", 255))
|
|
|
|
// 时间函数
|
|
fmt.Printf(" now() = %d\n", callFunction("now"))
|
|
|
|
// 9. 显示已注册的函数
|
|
fmt.Println("\n📋 已注册的函数:")
|
|
allFunctions := functions.ListAll()
|
|
for name, fn := range allFunctions {
|
|
fmt.Printf(" %s (%s): %s\n", name, fn.GetType(), fn.GetDescription())
|
|
}
|
|
|
|
fmt.Println("\n✅ 示例完成!")
|
|
}
|
|
|
|
// 辅助函数：调用函数并返回结果
|
|
func callFunction(name string, args ...interface{}) interface{} {
|
|
ctx := &functions.FunctionContext{
|
|
Data: make(map[string]interface{}),
|
|
}
|
|
|
|
result, err := functions.Execute(name, ctx, args)
|
|
if err != nil {
|
|
return fmt.Sprintf("Error: %v", err)
|
|
}
|
|
return result
|
|
}
|