I have code like this:
func o(){
var obj []struct {
Field1 string `json:"field1"`
Field2 string `json:"field2"`
Field3 string `json:"field3"`
}
}
I want to insert this []struct into database using another concurrent function which is being declared outside of this function.
how do I insert this type of data using gorm?
Related
I have the following table schema:
user
-----
id uuid
name string
user_model
------
id uuid
user_id uuid
model_id uuid
role int
model
_____
id uuid
name string
model_no string
I have the following code which fetches the data from the "model" table.
underlyingModel = &model{}
var model IModel
model = underlyingModel
role := 0
db.Table("model").Joins('INNER JOIN user_model ON user.id = user_model.uuid')
.Joins('INNER JOIN model ON user.id = model_id').Find(&model);
In my actual code, the model can be many different struct types with different fields, they're all behind the IModel interface.
What I want to do is to fetch that extra role field from the user_model in one query. Something like .Find(&model, &role).
Is it possible using Gorm?
One possible solution is to create an anonymous struct to put the results in, with a combination of the Select() method.
var selectModel struct {
ID string //I'm assuming uuid matches the string
Name string
ModelNo string
Role int
}
db.Table("model").
Joins("INNER JOIN user_model ON user.id = user_model.uuid").
Joins("INNER JOIN model ON user.id = model_id").
Select("model.id, model.name, model.model_no, user_model.role").
Find(&selectModel);
Basically, you create an anonymous struct with selectModel variable, containing all the fields you want to return. Then, you need to do a select statement because you need some fields that are not part of the model table.
Here you can find more info on Smart Select Fields in form.
EDIT:
Based on additional info from the comments, there is a solution that might work.
Your IModel interface could have two methods in its signature, one to extract a string for the SELECT part of the SQL query, and the other one to get a pointer of the selectModel that you would use in the Find method.
type IModel interface {
SelectFields() string
GetSelectModel() interface{}
}
The implementation would go something like this:
func (m *model) SelectFields() string {
return "model.id, model.name, model.model_no, user_model.role"
}
func (m *model) GetSelectModel() interface{} {
return &m.selectModel
}
type model struct {
selectModel
ID uint64
Age int
}
type selectModel struct {
Name string
Email string
}
Then, your query could look something like this:
var m IModel
m = model{}
db.Table("model").
Joins("INNER JOIN user_model ON user.id = user_model.uuid").
Joins("INNER JOIN model ON user.id = model_id").
Select(m.GetSelectFields()).
Find(m.GetSelectModel());
I am using Sequelize query for postgrsql db.
I have one field in table, that's type is JSONB. I would like to get data from table like not contain particular value from that field.
For example:
I have field 'field1' JSONB type.
field1 :[8,10,23] values
No need to fetch particular row, if the field1 have value 8. Those rows don't have field1 with 8 i need to fetch those rows.
{
[Op.not]:{
field1:
{
[Op.contains]: [8]
}
}
}
I tried above query but its not getting.
Try this:
{
field1:
{
[Op.not]:{
[Op.contains]: [8]
}
}
}
I'm using go-pg (https://github.com/go-pg/pg) and this code:
type Book struct {
id int
name string
}
var books []Book
err := db.Model(&books).Select()
and everything works good but I need to add a "virtual" column like this:
concat ('info:', 'id:', id, '...') AS info
and I tried to use:
query.ColumnExpr("concat ('info:', 'id:', id, '...') AS info")
but:
go-pg complains with: error="pg: can't find column=info in model=Book (try discard_unknown_columns)"
go-pg doesn't include anymore columns id and name in query: concat... ONLY!
I can understand that because now go-pg doesn't know how to bind data, but I really need that string which I can retrieve from DB only.
Is there a way?
Can I use a custom type like this below?
type CustomBook struct {
Info string
Book
}
Does this make sense?
this approach could work for you:
type Book struct {
ID int
Name string
Info string `pg:"-"`
}
...
db.Model(&books).ColumnExpr("book.*").ColumnExpr("CONCAT('id:', id, 'name:', name) AS info").Select()
pg:"-" ignores the struct field and it is not created nor it produces any errors
this ignored column is documented here: https://pg.uptrace.dev/models/
another approach, depending on your requirements could be like this:
var r []struct {
Name string
Info string
}
db.Model((*Book)(nil)).Column("name").ColumnExpr("CONCAT('id:', id, 'name:', name) AS info").Select(&r)
this second one is documented here: https://pg.uptrace.dev/queries/
local users = {}
table.insert(users, {['uid']= 'xxx'})
How to insert object into table in Lua script. When I try to insert, Lua returns empty array, with empty array inside "[[]]".
table.insert(users, 'xxx')
When I insert string, it is properly returned. "['xxx']"
I'm running Lua inside redis. In node.
JavaScript example would be:
const arr = []
arr.push({uid: 'xxx'})
try this method to get element : users[1].uid or users[1].['uid']
local users = {}
table.insert(users, { ['uid'] = 'xxx'})
table.insert(users, { uid = 'yyy'})
print(users[1].uid)
print(users[2].uid)
output:
xxx
yyy
I'm trying to concatenate the element of int array to one string in hive.
The function concat_ws works only for string arrays, so I tried cast(my_int_array as string) but it's not working.
Any suggestion?
Try to transform using /bin/cat:
from mytable select transform(my_int_array) using '/bin/cat' as (my_int_array);
Second option is to alter table and replace delimiters:
1) ALTER TABLE mytable CHANGE COLUMN my_int_array = my_int_array_string string;
2) SELECT REPLACE(my_int_array_string, '\002', ', ') FROM mytable;
It seems that the easiest way is to write a custom UDF to perform this specific task:
public class ConcatIntArray extends UDF {
public String evaluate(ArrayList<Integer> in, final String delimiter){
return in.stream().map(u-> String.valueOf(u)).collect(Collectors.joining(delimiter));
}
}