Raw Query
Most of the time, you should not use raw queries. Raw queries should only be considered when there is no other choice.
- Using Raw SQL to query doesn’t require an ORM definition
- Multiple databases support
?
as placeholders and auto convert. - The params of query support Model Struct, Slice and Array
Example:
o := orm.NewOrm()
ids := []int{1, 2, 3}
var r RawSter
r = o.Raw("SELECT name FROM user WHERE id IN (?, ?, ?)", ids)
Exec
Run sql query and return sql.Result object
res, err := o.Raw("UPDATE user SET name = ?", "your").Exec()
if err == nil {
num, _ := res.RowsAffected()
fmt.Println("mysql row affected nums: ", num)
}
QueryRow And QueryRows
API:
QueryRow(containers ...interface{}) error
QueryRows(containers ...interface{}) (int64, error)
They will use the returned values to initiate container
。
Example:
var name string
var id int
// id==2 name=="slene"
dORM.Raw("SELECT 'id','name' FROM `user`").QueryRow(&id,&name)
In this example, QueryRow
will query to get two columns and only one row. In this case, the values of the two columns are assigned to id
and name
respectively.
QueryRows Example:
var ids []int
var names []int
query = "SELECT 'id','name' FROM `user`"
// ids=>{1,2},names=>{"nobody","slene"}
num, err = dORM.Raw(query).QueryRows(&ids,&names)
Similarly, QueryRows
is also returned by column, so you can notice that in the example we have declared two slices corresponding to the columns id
and name
respectively。
SetArgs
Changing args param in Raw(sql, args…) can return a new RawSeter:
SetArgs(...interface{}) RawSeter
Example:
var name string
var id int
query := "SELECT 'id','name' FROM `user` WHERE `id`=?"
// id==2 name=="slene"
// 等效于"SELECT 'id','name' FROM `user` WHERE `id`=1"
dORM.Raw(query).SetArgs(1).QueryRow(&id,&name)
It can also be used in a single sql statement, reused, replacing parameters and then executed.
res, err := r.SetArgs("arg1", "arg2").Exec()
res, err := r.SetArgs("arg1", "arg2").Exec()
Values / ValuesList / ValuesFlat
Values(container *[]Params, cols ...string) (int64, error)
ValuesList(container *[]ParamsList, cols ...string) (int64, error)
ValuesFlat(container *ParamsList, cols ...string) (int64, error)
More details refer:
RowsToMap
RowsToMap(result *Params, keyCol, valueCol string) (int64, error)
SQL query results
name | value |
---|---|
total | 100 |
found | 200 |
map rows results to map
res := make(orm.Params)
nums, err := o.Raw("SELECT name, value FROM options_table").RowsToMap(&res, "name", "value")
// res is a map[string]interface{}{
// "total": 100,
// "found": 200,
// }
RowsToStruct
RowsToStruct(ptrStruct interface{}, keyCol, valueCol string) (int64, error)
SQL query results
name | value |
---|---|
total | 100 |
found | 200 |
map rows results to struct
type Options struct {
Total int
Found int
}
res := new(Options)
nums, err := o.Raw("SELECT name, value FROM options_table").RowsToStruct(res, "name", "value")
fmt.Println(res.Total) // 100
fmt.Println(res.Found) // 200
support name conversion: snake -> camel, eg: SELECT user_name … to your struct field UserName.
Prepare
Prepare once and exec multiple times to improve the speed of batch execution.
p, err := o.Raw("UPDATE user SET name = ? WHERE name = ?").Prepare()
res, err := p.Exec("testing", "slene")
res, err = p.Exec("testing", "astaxie")
...
...
p.Close() // Don't forget to close the prepare statement.