postgresql

1、记得要开启服务

pg_ctl -D /usr/local/var/postgres start

不然会出现

➜  bin psql book
psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

2、在terminal中运行的SQL语句用的双引号是' '。

然后关于sqlx包

db.Exec，执行的Query只是那些insert多。因为其是没返回值的。

返回一个lastInsertIndex-----这个在postgresql中是没用的，还有一个就是rowsAffect。所以，恩。

stmt, err := db.Prepare()也是一样，stmt.Exec是返回sql.result的 

    //pg不支持这个函数，因为他没有类似MySQL的自增ID
    // id, err := res.LastInsertId()
    // checkErr(err)
    // fmt.Println(id)

    var lastInsertId int
    err = db.QueryRow("INSERT INTO userinfo(username,departname,created) VALUES($1,$2,$3) returning uid;", "astaxie", "研发部门", "2012-12-09").Scan(&lastInsertId)
    checkErr(err)
    fmt.Println("最后插入id =", lastInsertId)

3、用sql.Query就不是了，返回的是sql.rows

还可以用来执行insert呢

4、一个模板

package main

import (
    "fmt"
    "log"

    "github.com/jmoiron/sqlx"
    _ "github.com/lib/pq"
)

func connDatabase(databaseTypeName string, user string, password string, databaseName string) *sqlx.DB {
    db, err := sqlx.Open(databaseTypeName, "user="+user+" password="+password+" dbname="+databaseName+" sslmode=disable")
    checkError(err, "open database")
    return db
}

func main() {
    db := connDatabase("postgres", "vimi", "stupidone", "test")
    defer db.Close()

    result, err := db.Exec("select * from story")
    fmt.Println(result.RowsAffected())
    checkError(err, "select")

    rows, err := db.Queryx("select * from story")
    checkError(err, "Queryx")

    for rows.Next() {
        var createUser, url, createDate string
        err := rows.Scan(&createUser, &url, &createDate)
        checkError(err, "rows")
        fmt.Println(createUser)
        fmt.Println(url)
        fmt.Println(createDate)
    }

    // stmt, err := db.Prepare("select * from story")
    // defer stmt.Close()
    // checkError(err, "stmt")

    //and also can this
    rr, err := db.Queryx("insert into story(create_user, url, create_date) values($1, $2, $3)", "jack", "google.com", "yesterday")
    fmt.Println(rr)
    checkError(err, "insert")
}

func checkError(err error, name string) {
    if err != nil {
        log.Fatal(err.Error() + " ---- " + name)
    }
}