homework-jianmu/docs/examples/go/sqlquery/main.go

87 lines
2.9 KiB
Go

package main
import (
"database/sql"
"fmt"
"log"
"time"
_ "github.com/taosdata/driver-go/v3/taosSql"
)
func main() {
var taosDSN = "root:taosdata@tcp(localhost:6030)/"
db, err := sql.Open("taosSql", taosDSN)
if err != nil {
log.Fatalln("Failed to connect to " + taosDSN + ", ErrMessage: " + err.Error())
}
defer db.Close()
// ANCHOR: create_db_and_table
// create database
res, err := db.Exec("CREATE DATABASE IF NOT EXISTS power")
if err != nil {
log.Fatalln("Failed to create database power, ErrMessage: " + err.Error())
}
rowsAffected, err := res.RowsAffected()
if err != nil {
log.Fatalln("Failed to get create database rowsAffected, ErrMessage: " + err.Error())
}
// you can check rowsAffected here
fmt.Println("Create database power successfully, rowsAffected: ", rowsAffected)
// create table
res, err = db.Exec("CREATE STABLE IF NOT EXISTS power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (groupId INT, location BINARY(24))")
if err != nil {
log.Fatalln("Failed to create stable meters, ErrMessage: " + err.Error())
}
rowsAffected, err = res.RowsAffected()
if err != nil {
log.Fatalln("Failed to get create stable rowsAffected, ErrMessage: " + err.Error())
}
// you can check rowsAffected here
fmt.Println("Create stable power.meters successfully, rowsAffected:", rowsAffected)
// ANCHOR_END: create_db_and_table
// ANCHOR: insert_data
// insert data, please make sure the database and table are created before
insertQuery := "INSERT INTO " +
"power.d1001 USING power.meters TAGS(2,'California.SanFrancisco') " +
"VALUES " +
"(NOW + 1a, 10.30000, 219, 0.31000) " +
"(NOW + 2a, 12.60000, 218, 0.33000) " +
"(NOW + 3a, 12.30000, 221, 0.31000) " +
"power.d1002 USING power.meters TAGS(3, 'California.SanFrancisco') " +
"VALUES " +
"(NOW + 1a, 10.30000, 218, 0.25000) "
res, err = db.Exec(insertQuery)
if err != nil {
log.Fatalf("Failed to insert data to power.meters, sql: %s, ErrMessage: %s\n", insertQuery, err.Error())
}
rowsAffected, err = res.RowsAffected()
if err != nil {
log.Fatalf("Failed to get insert rowsAffected, sql: %s, ErrMessage: %s\n", insertQuery, err.Error())
}
// you can check affectedRows here
fmt.Printf("Successfully inserted %d rows to power.meters.\n", rowsAffected)
// ANCHOR_END: insert_data
// ANCHOR: select_data
// query data, make sure the database and table are created before
sql := "SELECT ts, current, location FROM power.meters limit 100"
rows, err := db.Query(sql)
if err != nil {
log.Fatalf("Failed to query data from power.meters, sql: %s, ErrMessage: %s\n", sql, err.Error())
}
for rows.Next() {
// Add your data processing logic here
var (
ts time.Time
current float32
location string
)
err = rows.Scan(&ts, &current, &location)
if err != nil {
log.Fatalf("Failed to scan data, sql: %s, ErrMessage: %s\n", sql, err)
}
fmt.Printf("ts: %s, current: %f, location: %s\n", ts, current, location)
}
// ANCHOR_END: select_data
}