使用Golang操作PostgreSQL資料庫的增刪改查 CRUD Of PostgreSQL By Golang
摘要：
PG驅動庫包github.com/lib/pq
該驅動包沒有提供建立PG表結構的函式，因此需要手動建立。SQL檔案如下：
node_infos.sql
---------------------------
---postgresql SQL by Chen Jian
------...
PG驅動庫包github.com/lib/pq
該驅動包沒有提供建立PG表結構的函式，因此需要手動建立。SQL檔案如下：
node_infos.sql
---------------------------
---postgresql SQL by Chen Jian
---------------------------
drop table if exists "node_infos";
CREATE TABLE "node_infos"(
"node_name" varchar(45) PRIMARY KEY,
"node_ip" varchar(45) NOT NULL,
"node_port" varchar(45) NOT NULL,
"node_username" varchar(45) NOT NULL,
"node_password" varchar(255) NOT NULL
);
COMMENT ON COLUMN "node_infos"."node_name" is '節點名稱';
COMMENT ON COLUMN "node_infos"."node_ip" is '節點IP地址';
COMMENT ON COLUMN "node_infos"."node_port" is '節點埠號';
COMMENT ON COLUMN "node_infos"."node_username" is '節點使用者名稱';
COMMENT ON COLUMN "node_infos"."node_password" is '節點密碼';
INSERT INTO node_infos(node_name, node_ip, node_port, node_username, node_password)
VALUES ('chen', '10.16.11.92', '22', 'root', 'xxxx');
INSERT INTO node_infos(node_name, node_ip, node_port, node_username, node_password)
VALUES ('jian', '10.16.11.94', '22', 'root', 'xxxx');
INSERT INTO node_infos(node_name, node_ip, node_port, node_username, node_password)
VALUES ('blabla', '10.16.11.95', '22', 'root', 'xxxx');
PGs資料庫的簡單操作
# 進入PG資料庫 psql -U postgres # 檢視當前資料庫： \l; <<'COMMENT' List of databases Name|Owner| Encoding |Collate|Ctype|Access privileges -----------+----------+----------+------------+------------+----------------------- postgres| postgres | UTF8| en_US.utf8 | en_US.utf8 | template0 | postgres | UTF8| en_US.utf8 | en_US.utf8 | =c/postgres+ ||||| postgres=CTc/postgres template1 | postgres | UTF8| en_US.utf8 | en_US.utf8 | =c/postgres+ ||||| postgres=CTc/postgres (3 rows) COMMENT # 連結資料庫postgres \c postgres; <<'COMMENT' You are now connected to database "postgres" as user "postgres". COMMENT # 建立表 \i node_infos.sql; # 結果輸出 psql:node_infos.sql:4: NOTICE:table "node_infos" does not exist, skipping DROP TABLE CREATE TABLE COMMENT COMMENT COMMENT COMMENT COMMENT INSERT 0 1 INSERT 0 1 INSERT 0 1 # 檢視當前表 \dt; <<'COMMENT' List of relations Schema |Name| Type|Owner --------+------------+-------+---------- public | node_infos | table | postgres (1 row) COMMENT # 查看錶結構 \d node_infos; <<'COMMENT' Table "public.node_infos" Column|Type| Modifiers ---------------+------------------------+----------- node_name| character varying(45)| not null node_ip| character varying(45)| not null node_port| character varying(45)| not null node_username | character varying(45)| not null node_password | character varying(255) | not null Indexes: "node_infos_pkey" PRIMARY KEY, btree (node_name) COMMENT # 查看錶中所有資料 select * from node_infos; <<'COMMENT' node_name |node_ip| node_port | node_username | node_password -----------+-------------+-----------+---------------+--------------- chen| 10.16.11.92 | 22| root| xxxx jian| 10.16.11.94 | 22| root| xxxx blabla| 10.16.11.95 | 22| root| xxxx (3 rows) COMMENT # 刪除表 drop table node_infos; <<'COMMENT' DROP TABLE COMMENT # 退出PG資料庫 \q;
CRUD程式碼
package main
/*
Author: Chen Jian
Blog:https://www.o-my-chenjian.com
Date:2018-11-20
*/
import (
"fmt"
"log"
"database/sql"
_ "github.com/lib/pq"
)
var db *sql.DB
var err error
// PGs資料庫資訊
const (
pg_host= "10.16.11.95"
pg_port= 5432
pg_user= "postgres"
pg_password = "postgres"
pg_dbname= "postgres"
)
func InsertNodeInfo() error {
stmt, err := db.Prepare("INSERT INTO \"node_infos\"(\"node_name\", \"node_ip\", \"node_port\", \"node_username\", \"node_password\") VALUES ($1, $2, $3, $4, $5)")
if err != nil {
log.Fatal("PG Statements Wrong: ", err)
}
res, err := stmt.Exec("nicai", "10.51.42.66", "9999", "nicai", "gophdddeer")
if err != nil {
log.Fatal("PG Statements Exec Wrong: ", err)
}
id, err := res.RowsAffected()
if err != nil {
log.Fatal("PG Affecte Wrong: ", err)
}
fmt.Println(id)
return nil
}
func DeleteNodeInfo() error {
stmt, err := db.Prepare("DELETE FROM \"node_infos\" WHERE \"node_name\" = $1")
if err != nil {
log.Fatal("PG Statements Wrong: ", err)
}
res, err := stmt.Exec("nicai")
if err != nil {
log.Fatal("PG Statements Exec Wrong: ", err)
}
id, err := res.RowsAffected()
if err != nil {
log.Fatal("PG Affecte Wrong: ", err)
}
fmt.Println(id)
return nil
}
func SelectAllNodeInfo() error {
rows, err := db.Query("SELECT * FROM\"node_infos\"")
if err != nil {
log.Fatal("PG Statements Wrong: ", err)
}
for rows.Next() {
var nodename string
var nodeip string
var nodeport string
var nodeusername string
var nodepassword string
if err := rows.Scan(&nodename, &nodeip, &nodeport, &nodeusername, &nodepassword); err != nil {
log.Fatal("PG Rows Scan Failed: ", err)
}
fmt.Printf("node_name = \"%s\", "+
"node_ip = \"%s\", "+
"node_port = \"%s\", "+
"node_username = \"%s\", "+
"node_password = \"%s\"\n", nodename, nodeip, nodeport, nodeusername, nodepassword)
}
if err := rows.Err(); err != nil {
log.Fatal("PG Query Failed: ", err)
}
rows.Close()
db.Close()
return nil
}
func UpdateNodeInfo() error {
stmt, err := db.Prepare("UPDATE \"node_infos\" SET \"node_username\" = $1 WHERE \"node_name\" = $2")
if err != nil {
log.Fatal("PG Statements Wrong: ", err)
}
res, err := stmt.Exec("blabla", "blabla")
if err != nil {
log.Fatal("PG Statements Exec Wrong: ", err)
}
id, err := res.RowsAffected()
if err != nil {
log.Fatal("PG Affecte Wrong: ", err)
}
fmt.Println(id)
return nil
}
func main() {
// 連結PostgreSQL資料庫
log.Println("Connecting PostgreSQL....")
psqlInfo := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=%s sslmode=disable", pg_host, pg_port, pg_user, pg_password, pg_dbname)
db, err = sql.Open("postgres", psqlInfo)
if err != nil {
log.Fatal("Connect PG Failed: ", err)
}
db.SetMaxOpenConns(2000)
db.SetMaxIdleConns(1000)
defer db.Close()
err = db.Ping()
if err != nil {
log.Fatal("Ping GP Failed: ", err)
}
fmt.Println("PG Successfull Connected!")
// 插入資料
//err := InsertNodeInfo()
//if err != nil {
//log.Fatal("Insert Data Failed: ", err)
//}
// 刪除資料
//err := DeleteNodeInfo()
//if err != nil {
//log.Fatal("Delete Data Failed: ", err)
//}
// 查詢所有資料
//err := SelectAllNodeInfo()
//if err != nil {
//log.Fatal("Select All Data Failed: ", err)
//}
// 更新某一資料
err := UpdateNodeInfo()
if err != nil {
log.Fatal("Update Data Failed: ", err)
}
}
PG驅動庫包github.com/lib/pq
採用github.com/lib/pq
主要是其提供建立資料庫表的方法。
package main
/*
Author: Chen Jian
Blog:https://www.o-my-chenjian.com
Date:2018-11-20
*/
import (
"fmt"
"log"
"github.com/go-pg/pg"
"github.com/go-pg/pg/orm"
)
// PGs資料庫資訊
const (
pg_addr= "10.16.11.95:5432"
pg_user= "postgres"
pg_password = "postgres"
pg_dbname= "postgres"
)
// 定義表結構
type NodeInfo struct {
NodeNamestring `sql:"type:varchar(45),unique,notnull,pk"`
NodeIpstring `sql:"type:varchar(45),notnull"`
NodePortstring `sql:"type:varchar(45),notnull"`
NodeUsername string `sql:"type:varchar(45),notnull"`
NodePassword string `sql:"type:varchar(255),notnull"`
}
func CreateTable(db *pg.DB) error {
for _, model := range []interface{}{(*NodeInfo)(nil)} {
err := db.CreateTable(model, &orm.CreateTableOptions{
IfNotExists:true,
FKConstraints: true,
})
if err != nil {
return err
}
}
return nil
}
func DeleteTable(db *pg.DB) error {
err := db.DropTable(&NodeInfo{}, &orm.DropTableOptions{
IfExists: true,
Cascade:true,
})
return err
}
func InsertNodeInfo(db *pg.DB) error {
// 插入資料方法一
//nodeinfodata := &NodeInfo{
//NodeName:"chenjian",
//NodeIp:"10.0.0.5",
//NodePort:"2222",
//NodeUsername: "chenjian",
//NodePassword: "1234321",
//}
//err := db.Insert(nodeinfodata)
//if err!=nil {
//return err
//}
// 插入資料方法二
err := db.Insert(&NodeInfo{
NodeName:"chenjian",
NodeIp:"10.0.0.5",
NodePort:"2222",
NodeUsername: "chenjian",
NodePassword: "1234321",
})
if err != nil {
return err
}
return nil
}
func SelectAllNodeInfo(db *pg.DB) error {
var nodeinfodata []NodeInfo
err := db.Model(&nodeinfodata).Select()
if err != nil {
return err
}
fmt.Println(nodeinfodata)
return nil
}
func SelectNodeInfo(db *pg.DB) error {
nodeinfodata := &NodeInfo{
NodeName: "chenjian",
}
err := db.Select(nodeinfodata)
if err != nil {
return err
}
fmt.Println(nodeinfodata)
return nil
}
func UpdateNodeInfo(db *pg.DB) error {
var nodeinfodata []NodeInfo
updatedata := &NodeInfo{
NodeName:"chenjian",
NodeIp:"10.0.0.5",
NodePort:"3333",
NodeUsername: "chenjian",
NodePassword: "1234321",
}
_, err := db.Model(&nodeinfodata).
Set("node_port = ?", updatedata.NodePort).
Where("node_name = ?", updatedata.NodeName).
Returning("*").
Update()
if err != nil {
return err
}
return nil
}
func main() {
// 連結PostgreSQL資料庫
log.Println("Connecting PostgreSQL....")
db := pg.Connect(&pg.Options{
Addr:pg_addr,
User:pg_user,
Password: pg_password,
Database: pg_dbname,
})
defer db.Close()
fmt.Println("Successfull Connected!")
// 建立表
//err := CreateTable(db)
//if err != nil {
//log.Fatal("Create Table Failed: ",err)
//}
// 刪除表
//err := DeleteTable(db)
//if err != nil {
//log.Fatal("Delete Table Failed: ", err)
//}
// 插入資料
//err := InsertNodeInfo(db)
//if err != nil {
//log.Fatal("Insert Data Failed: ", err)
//}
// 查詢所有資料
//err := SelectAllNodeInfo(db)
//if err != nil {
//log.Fatal("Select All Data Failed: ", err)
//}
// 查詢某一資料
//err := SelectNodeInfo(db)
//if err != nil {
//log.Fatal("Select Data Failed: ", err)
//}
// 更新某一資料
err := UpdateNodeInfo(db)
if err != nil {
log.Fatal("Update Data Failed: ", err)
}
}
govendor依賴管理工具
通過govendor
可以很方便的管理專案中所有的依賴包。例如將依賴包放到專案路徑下，便於專案的傳遞，從而不需再一次下載依賴包。
govendor的安裝
go get -u github.com/kardianos/govendor
# 無法下載成功，可以下載原始碼，進行編譯
mkdir -p ${GOPATH}/src/github.com/kardianos
cd ${GOPATH}/src/github.com/kardianos
git clone https://github.com/kardianos/govendor.git govendor
govendor的操作
# 進入專案路徑 cd ${GOPATH}/src/chenjian # 初始化govendor。隨後會生成一個vender資料夾，裡面有個vender.json，記錄著依賴包的資訊 govendor init # 檢視專案中所需依賴列表，狀態內容如下 govendor list # 檢視正在使用的依賴包 govendor list -v fmt # 下載missing的依賴包，下載完後，+missing變為+external狀態 govendor get k8s.io/klog # 下載特定版本的依賴包 govendor fetch golang.org/x/net/[email protected] # Get latest v1.*.* tag or branch. govendor fetch golang.org/x/net/[email protected] # Get the tag or branch named "v1". govendor fetch golang.org/x/net/[email protected]=v1 # 將+external狀態的依賴包歸到govender管理 govendor add k8s.io/klog # 批量add govendor add +e
- vender.json
{
"comment": "",
"ignore": "test",
"package": [
{
"checksumSHA1": "asksIwylfIjaYsF2nMY69jTyxC0=",
"path": "github.com/lib/pq",
"revision": "9eb73efc1fcc404148b56765b0d3f61d9a5ef8ee",
"revisionTime": "2018-10-16T16:26:27Z"
}
],
"rootPath": "chenjian"
}
- 依賴包狀態
| 狀態 | 縮寫 | 含義 |
|---|---|---|
| +local | l | 在專案中的包 |
| +external | e | 外部包，即被 $GOPATH 管理，但不在 vendor 目錄下 |
| +vendor | v | 已被 govendor 管理，即在 vendor 目錄下 |
| +std | s | 標準庫中的包 |
| +unused | u | 未使用的包，即包在 vendor 目錄下，但專案並沒有用到 |
| +missing | m | 程式碼引用了依賴包，但該包並沒有找到 |
| +program | p | 主程式包，意味著可以編譯為執行檔案 |
| +outside | 外部包和缺失的包 | |
| +all | 所有的包 |