sql构建
最后更新于：2022-04-02 04:52:50
## SQL构建
### 1. 执行原生SQL
~~~
db.Exec("DROP TABLE users;")
db.Exec("UPDATE orders SET shipped_at=? WHERE id IN (?)", time.Now, []int64{11,22,33})
// Scan
type Result struct {
Name string
Age int
}
var result Result
db.Raw("SELECT name, age FROM users WHERE name = ?", 3).Scan(&result)
~~~
### 2. sql.Row & sql.Rows
获取查询结果为`*sql.Row`或`*sql.Rows`
~~~
row := db.Table("users").Where("name = ?", "jinzhu").Select("name, age").Row() // (*sql.Row)
row.Scan(&name, &age)
rows, err := db.Model(&User{}).Where("name = ?", "jinzhu").Select("name, age, email").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
...
rows.Scan(&name, &age, &email)
...
}
// Raw SQL
rows, err := db.Raw("select name, age, email from users where name = ?", "jinzhu").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
...
rows.Scan(&name, &age, &email)
...
}
~~~
### 3. 迭代中使用sql.Rows的Scan
~~~
rows, err := db.Model(&User{}).Where("name = ?", "jinzhu").Select("name, age, email").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
var user User
db.ScanRows(rows, &user)
// do something
}
~~~
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