#Model
class You(models.Model):
Name = models.TextField(null=False)
Age = models.IntegerField(null=False)
# What i want to do
data = [["john", 16] ,["jax", 18]]
for d in data:
You(*d)
Then it tries to override id.
i set to editable=False but it can't help too
Any way to skip id field ?
Assign it with named parameters:
# What i want to do
data = [['john', 16], ['jax', 18]]
for name, age in data:
You(Name=name, Age=age)
Another option is to pass DEFERRED for the primary key, so:
from django.db.models import DEFERRED
for d in data:
You(DEFERRED, *d)
Note: normally the name of the fields in a Django model are written in snake_case, not PascalCase, so it should be: age instead of Age.
Note: Specifying null=False [Django-doc] is not necessary: fields are by default not NULLable.
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 have a very big model in models.py:
simplified version is:
class MyModel(models.Model):
item_1 = models.FloatField(null=True, blank=True)
...
item_20 = models.FloatField(null=True, blank=True)
in views.py:
def form_valid(self, form_class):
instance = form_class.save(commit=False)
for i in range(1, 20):
name = 'item_' + str(i)
instance.name = i
With this the field name 'item_1' ... to 'item_20' in instance is not recogniced. Instead 'name' is added to instance like other new field...
How can I iterate and save my model?
Any suggestion?
Thanks!!!
You should probably use setattr in order to loop through the fields and set the values in them. Try this:
def form_valid(self, form_class):
instance = form_class.save(commit=False)
for i in range(1, 20):
name = 'item_' + str(i)
setattr(instance, name, value) # Where value is the data you wanted to save in the field `name`
Similary user getattr() to get the data by looping through the class instance.
So I have SQLite database using Slick and I want to add and remove tables from it.
Here is what I have now:
Here is the database element class:
class Data(tag: Tag)
extends Table[(Int, String)](tag, "myDB") {
// This is the primary key column:
def id = column[Int]("ID", O.PrimaryKey)
def name = column[String]("NAME")
// Every table needs a * projection with the same type as the table's type parameter
def * : ProvenShape[(Int, String)] = (id, name)
}
I need to be able to create multiple tables using the class above. Something like this:
def addTable(name:String){
db withSession { implicit session =>
val newTable = TableQuery[Data]
newTable.ddl.create
}
}
Problem is that I cant create new table because one already exists with name "myDB". I tried to add a parameter for the name of the Table in the class Data like so:
class Data(tag: Tag,tableName:String)
But then I couldn't create a table at all and got an error
unspecified value parameter tableName
And how can I query a specific table from the database given the table name?
I tried to Implement this using Map with table name pointing to a table, but it doesnt work because the Map is not saved anywhere and is reset everytime the program starts.
This is what I had for querying a table:
def getDataFromTable(tableName:String)
{
var res = ""
db withSession { implicit session =>
tables(tableName) foreach{
case (id,name)=>
res += id + " " + name + " "
}
}
res
}
Any help is appreciated!
Thanks!
Definition
class Data(tag: Tag, tableName: String)
extends Table[(Int, String)](tag, tableName){
...
Usage
(new TableQuery(Data(_,"table_1"))).ddl.create
(new TableQuery(Data(_,"table_2"))).ddl.create
...
According to the Dapper documentation, you can get a dynamic list back from dapper using below code :
var rows = connection.Query("select 1 A, 2 B union all select 3, 4");
((int)rows[0].A)
.IsEqualTo(1);
((int)rows[0].B)
.IsEqualTo(2);
((int)rows[1].A)
.IsEqualTo(3);
((int)rows[1].B)
.IsEqualTo(4);
What is however the use of dynamic if you have to know the field names and datatypes of the fields.
If I have :
var result = Db.Query("Select * from Data.Tables");
I want to be able to do the following :
Get a list of the field names and data types returned.
Iterate over it using the field names and get back data in the following ways :
result.Fields
["Id", "Description"]
result[0].values
[1, "This is the description"]
This would allow me to get
result[0].["Id"].Value
which will give results 1 and be of type e.g. Int 32
result[0].["Id"].Type --- what datattype is the value returned
result[0].["Description"]
which will give results "This is the description" and will be of type string.
I see there is a results[0].table which has a dapperrow object with an array of the fieldnames and there is also a result.values which is an object[2] with the values in it, but it can not be accessed. If I add a watch to the drilled down column name, I can get the id. The automatically created watch is :
(new System.Collections.Generic.Mscorlib_CollectionDebugView<Dapper.SqlMapper.DapperRow>(result as System.Collections.Generic.List<Dapper.SqlMapper.DapperRow>)).Items[0].table.FieldNames[0] "Id" string
So I should be able to get result[0].Items[0].table.FieldNames[0] and get "Id" back.
You can cast each row to an IDictionary<string, object>, which should provide access to the names and the values. We don't explicitly track the types currently - we simply don't have a need to. If that isn't enough, consider using the dapper method that returns an IDataReader - this will provide access to the raw data, while still allowing convenient call / parameterization syntax.
For example:
var rows = ...
foreach(IDictionary<string, object> row in rows) {
Console.WriteLine("row:");
foreach(var pair in row) {
Console.WriteLine(" {0} = {1}", pair.Key, pair.Value);
}
}
I'm writing several Solr Custom Query Components.
Each component run different kinds of queries:
Component A: does a group by query field A
Component B: does a group by on a different fild B
Each component will send it's the documents from it's result to the next component.
In my "process" function, I'm donig the following after the result is set by grouping:
IndexSchema schema = searcher.getSchema();
DocListAndSet s = result.getDocListAndSet();
DocSet s3 = s.docSet;
DocIterator dit = s3.iterator()
while (dit.hasNext())
{
SolrDocument doc = new SolrDocument();
int docid = dit.nextDoc();
//float score = dit.score();<--This does not get the score
Document luceneDoc = searcher.doc(docid);//get the document using the doc id
for( Fieldable field : luceneDoc.getFields())
{
SchemaField sf = schema.getField( field.name() );
doc.addField( field.name(), sf.getType().toObject( field ) );
......
}
And then iterating through the Set and createing SolrDocument.
The SolrDocumentes are entered into a SolDocumentList and end I send it off to the next Component:
rb.req.getContext().put("TAG", list);
I also want to add a field called "score" SolrDocument, this field will contain the actual score. I've tried getting the score using:
float score = dit.score()
But the above does not get the score of the document. How do I get the "score" of the document using the document id?
Is there a particular reason you are getting the docSet instead of the docList?
I would try (condensing a bit) getting s.docList.iterator() instead of s.docSet.iterator(). The latter states specifically in the documentation here that you can't get meaningful scores from it, where the docList states it may contains valid scores.
Well you have to set GET_Scores in getDocList(query,List,Lsort,offset,maxnoofdocs,1)
Here
`
query is your query obj
List<Query> your filters could be null
lsort could be null
offset
maxnoofdocs integer
1 means get score with documents`