/
db.go
169 lines (151 loc) · 3.39 KB
/
db.go
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package main
import (
"database/sql"
"fmt"
"log"
maps "github.com/mitchellh/mapstructure"
)
// User model
type User struct {
ID int `db:"id"`
Name string `db:"name"`
Age int `db:"age"`
}
// InsertUser insert
func InsertUser(db *sql.DB, name string, age int) int64 {
str := `insert into user1 (name, age) values(:1, :2)`
res, err := sqlExec(db, str, name, age)
if err != nil {
log.Fatal(err)
}
lastInsertID, err := res.LastInsertId()
if err != nil {
log.Fatal(err)
}
return lastInsertID
}
// DeleteUser delete
func DeleteUser(db *sql.DB, id int) int64 {
str := `delete from user1 where id = :1`
res, err := sqlExec(db, str, id)
if err != nil {
log.Fatal(err)
}
rowsAffected, err := res.RowsAffected()
if err != nil {
log.Fatal(err)
}
return rowsAffected
}
// UpdateUser update
func UpdateUser(db *sql.DB, name string, age int, id int) int64 {
str := `update user1 set name=:1, age=:2 where id = :1`
res, err := sqlExec(db, str, name, age, id)
if err != nil {
log.Fatal(err)
}
rowsAffected, err := res.RowsAffected()
if err != nil {
log.Fatal(err)
}
return rowsAffected
}
// SelectUserByCondition selectone
func SelectUserByCondition(db *sql.DB, id int) int {
str := `select id, name, age from user1 where id = :1`
users, err := sqlQuery(db, str, id)
if err != nil {
log.Fatal(err)
}
for _, u := range users {
fmt.Printf("%d\t%s\t%d\n", u.ID, u.Name, u.Age)
}
return len(users)
}
// SelectAllUser selectall
func SelectAllUser(db *sql.DB) int {
str := `select id, name, age from user1`
users, err := sqlQuery(db, str)
if err != nil {
log.Fatal(err)
}
for _, u := range users {
fmt.Printf("%d\t%s\t%d\n", u.ID, u.Name, u.Age)
}
return len(users)
}
// SelectCount selectall
func SelectCount(db *sql.DB) int64 {
str := `select count(*) from user1`
count, err := sqlQueryCount(db, str)
if err != nil {
log.Fatal(err)
}
return count
}
func sqlQuery(db *sql.DB, sqlStmt string, args ...interface{}) (users []*User, err error) {
rows, err := db.Query(sqlStmt, args...)
if err != nil {
return
}
defer rows.Close()
// get columns
columns, err := rows.Columns()
values := make([]interface{}, len(columns))
scanArgs := make([]interface{}, len(columns))
// generate scanArgs
for i := range values {
scanArgs[i] = &values[i]
}
for rows.Next() {
if err = rows.Scan(scanArgs...); err != nil {
return
}
record := make(map[string]interface{})
for i, col := range values {
if col != nil {
record[columns[i]] = col
}
}
u := new(User)
convertMapToUser(&record, u)
users = append(users, u)
//log.Printf("row[%d], name=[%s], age=[%d]\n", u.ID, u.Name, u.Age)
}
err = rows.Err()
if err != nil {
return
}
//log.Println("SQL Query success rows queried")
return
}
func sqlQueryCount(db *sql.DB, sqlStmt string) (int64, error) {
var count int64
err := db.QueryRow(sqlStmt).Scan(&count)
if err != nil {
return 0, err
}
return count, nil
}
func sqlExec(db *sql.DB, sqlStmt string, params ...interface{}) (sql.Result, error) {
stmt, err := db.Prepare(sqlStmt)
if err != nil {
return nil, err
}
defer stmt.Close()
res, err := stmt.Exec(params...)
if err != nil {
fmt.Println(err)
return nil, err
}
return res, nil
}
func convertMapToUser(data *map[string]interface{}, out interface{}) {
cfg := &maps.DecoderConfig{
Metadata: nil,
Result: out,
TagName: "db",
}
decoder, _ := maps.NewDecoder(cfg)
decoder.Decode(*data)
}