61 lines
1.8 KiB
Go
61 lines
1.8 KiB
Go
package main
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import (
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"context"
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"database/sql"
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"fmt"
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"log"
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"time"
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_ "github.com/taosdata/driver-go/v3/taosSql"
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)
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func main() {
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taosDSN := "root:taosdata@tcp(localhost:6030)/"
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db, err := sql.Open("taosSql", taosDSN)
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if err != nil {
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log.Fatalln("Failed to connect to " + taosDSN + ", ErrMessage: " + err.Error())
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}
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defer db.Close()
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initEnv(db)
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// ANCHOR: query_id
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// use context to set request id
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reqId := int64(3)
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ctx := context.WithValue(context.Background(), "taos_req_id", reqId)
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// execute query with context
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querySql := "SELECT ts, current, location FROM power.meters limit 1"
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rows, err := db.QueryContext(ctx, querySql)
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if err != nil {
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log.Fatalf("Failed to execute sql with reqId: %d, url: %s, sql: %s, ErrMessage: %s\n", reqId, taosDSN, querySql, err.Error())
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}
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for rows.Next() {
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// Add your data processing logic here
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var (
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ts time.Time
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current float32
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location string
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)
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err = rows.Scan(&ts, ¤t, &location)
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if err != nil {
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log.Fatalf("Failed to scan data, reqId: %d, url:%s, sql: %s, ErrMessage: %s\n", reqId, taosDSN, querySql, err)
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}
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fmt.Printf("ts: %s, current: %f, location: %s\n", ts, current, location)
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}
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// ANCHOR_END: query_id
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}
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func initEnv(conn *sql.DB) {
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_, err := conn.Exec("CREATE DATABASE IF NOT EXISTS power")
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if err != nil {
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log.Fatal("Create database power error: ", err)
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}
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_, err = conn.Exec("CREATE STABLE IF NOT EXISTS power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (groupId INT, location BINARY(24))")
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if err != nil {
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log.Fatal("Create stable meters error: ", err)
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}
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_, err = conn.Exec("INSERT INTO power.d1001 USING power.meters TAGS (2, 'California.SanFrancisco') VALUES (NOW , 10.2, 219, 0.32)")
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if err != nil {
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log.Fatal("Insert data to power.meters error: ", err)
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}
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}
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