postgres操作

 

package postgres

import (
    "database/sql"
    "sync"

_ "github.com/lib/pq"

)

var (
    db  *sql.DB
    oncePg  sync.Once
)


func InitPostgres(host, user, password, dbname string, port pool int) *sql.DB{
    var err error
    if pool == 0 {
        pool = 10
    }
    ens := "host=%s port=%d user=%s password=%s dbname=%s sslmode=disable"
    pgEns := fmt.Sprintf(ens, host, port, user, password, dbname)

    oncePg.Do(func(){
        db, err = sql.Open("postgres")
        db.SetMaxOpenConns(pool)
    })
    if err != nil {
        panic(err)
    }
    // defer  db.Close()//defer关闭数据库连接
    return db
}

func UpdateCache() {
    rows, err := db.Query("select a,b,c,d::varchar,e,f,g,h::varchar from hero_info " +
        "join e_setting on c=ccc where b::varchar = '1'")
    if err != nil {
        panic(err)
    }
    defer rows.Close()
    for rows.Next() {
        var (
            id, n, pr                                  int
            r1, rw, re, re, r5         string
            state                                              bool
        )
        err := rows.Scan(&id, &r1, &r2, &pr, &n, &r3, &r4, &r5)
        if err != nil {
            panic(err)
        }
    err = rows.Err()
    if err != nil {
        panic(err)
    }
}