How to return a select query from jpa repository with foreign key type

I am try to do this:

@Query(value = "SELECT DISTINCT comarca_id FROM debito_negativacao WHERE 
debito_negativacao.status= :status", nativeQuery = true)
List<Comarca> findDistinctComarcaIdByStatus(@Param("status") String status);

But i have this error:

No converter found capable of converting from type [java.math.BigInteger] to type [com.hc.projects.model.Comarca]]

#java #spring-boot #hibernate

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How model queries work in Django

How model queries work in Django

Welcome to my blog, hey everyone in this article we are going to be working with queries in Django so for any web app that you build your going to want to write a query so you can retrieve information from your database so in this article I’ll be showing you all the different ways that you can write queries and it should cover about 90% of the cases that you’ll have when you’re writing your code the other 10% depend on your specific use case you may have to get more complicated but for the most part what I cover in this article should be able to help you so let’s start with the model that I have I’ve already created it.

**Read More : **How to make Chatbot in Python.

Read More : Django Admin Full Customization step by step

let’s just get into this diagram that I made so in here:

Describe each parameter in Django querset

we’re making a simple query for the myModel table so we want to pull out all the information in the database so we have this variable which is gonna hold a return value and we have our myModel models so this is simply the myModel model name so whatever you named your model just make sure you specify that and we’re gonna access the objects attribute once we get that object’s attribute we can simply use the all method and this will return all the information in the database so we’re gonna start with all and then we will go into getting single items filtering that data and go to our command prompt.

Here and we’ll actually start making our queries from here to do this let’s just go ahead and run** Python manage.py shell** and I am in my project file so make sure you’re in there when you start and what this does is it gives us an interactive shell to actually start working with our data so this is a lot like the Python shell but because we did manage.py it allows us to do things a Django way and actually query our database now open up the command prompt and let’s go ahead and start making our first queries.

#django #django model queries #django orm #django queries #django query #model django query #model query #query with django

SQL Foreign Key Constraint | Foreign Key In SQL Example

SQL foreign key is used to form a link between two tables, which makes it a referencing key.  The foreign key is a constraint, which is a column or a combination of the column which is used to point the  primary key of another table. If the table has the primary key defined on any field(s), then a user cannot have the two records having the same value of that field(s).

SQL Foreign Key Constraint

The primary purpose of the foreign key is that only those values will appear in the columns which are present in the primary key table and a foreign key is a referencing key in one table, the foreign key must match an existing primary key in the referenced table. This enforcement of foreign key is known as referential integrity.

Let’s understand the use of a foreign key with an example.

We are going to create a foreign key with create keyword.

See the following syntax.

Create table table_name(
Column1 datatype,
Column2 datatype,
……..,
Column(n) datatype,
Constraint (constraint name)
FOREIGN KEY [column1, column2…]
REFERENCES [primary_key_table] (column_list_of_primary_key_table) ….);

#sql #sql foreign key #foreign key

How to return a select query from jpa repository with foreign key type

I am try to do this:

@Query(value = "SELECT DISTINCT comarca_id FROM debito_negativacao WHERE 
debito_negativacao.status= :status", nativeQuery = true)
List<Comarca> findDistinctComarcaIdByStatus(@Param("status") String status);

But i have this error:

No converter found capable of converting from type [java.math.BigInteger] to type [com.hc.projects.model.Comarca]]

#java #spring-boot #hibernate

Understanding JPA and Other Query Construction Frameworks

Hibernate vs. JPA: several frameworks are available to generate the request or the command, but only some options are the most relevant. Let’s explore which.

JPA is the standard that guides the developer towards an object conceptualization of his application and provides him with an abstraction of the relational model. However, once the model is in place, several frameworks are available to generate the request or the command. Which choices are the most relevant? Let’s explore.

#java #spring data #querydsl #understanding jpa and other query construction frameworks #jpa #query construction frameworks

Basic Data Types in Python | Python Web Development For Beginners

At the end of 2019, Python is one of the fastest-growing programming languages. More than 10% of developers have opted for Python development.

In the programming world, Data types play an important role. Each Variable is stored in different data types and responsible for various functions. Python had two different objects, and They are mutable and immutable objects.

Table of Contents  hide

I Mutable objects

II Immutable objects

III Built-in data types in Python

Mutable objects

The Size and declared value and its sequence of the object can able to be modified called mutable objects.

Mutable Data Types are list, dict, set, byte array

Immutable objects

The Size and declared value and its sequence of the object can able to be modified.

Immutable data types are int, float, complex, String, tuples, bytes, and frozen sets.

id() and type() is used to know the Identity and data type of the object

a**=25+**85j

type**(a)**

output**:<class’complex’>**

b**={1:10,2:“Pinky”****}**

id**(b)**

output**:**238989244168

Built-in data types in Python

a**=str(“Hello python world”)****#str**

b**=int(18)****#int**

c**=float(20482.5)****#float**

d**=complex(5+85j)****#complex**

e**=list((“python”,“fast”,“growing”,“in”,2018))****#list**

f**=tuple((“python”,“easy”,“learning”))****#tuple**

g**=range(10)****#range**

h**=dict(name=“Vidu”,age=36)****#dict**

i**=set((“python”,“fast”,“growing”,“in”,2018))****#set**

j**=frozenset((“python”,“fast”,“growing”,“in”,2018))****#frozenset**

k**=bool(18)****#bool**

l**=bytes(8)****#bytes**

m**=bytearray(8)****#bytearray**

n**=memoryview(bytes(18))****#memoryview**

Numbers (int,Float,Complex)

Numbers are stored in numeric Types. when a number is assigned to a variable, Python creates Number objects.

#signed interger

age**=**18

print**(age)**

Output**:**18

Python supports 3 types of numeric data.

int (signed integers like 20, 2, 225, etc.)

float (float is used to store floating-point numbers like 9.8, 3.1444, 89.52, etc.)

complex (complex numbers like 8.94j, 4.0 + 7.3j, etc.)

A complex number contains an ordered pair, i.e., a + ib where a and b denote the real and imaginary parts respectively).

String

The string can be represented as the sequence of characters in the quotation marks. In python, to define strings we can use single, double, or triple quotes.

# String Handling

‘Hello Python’

#single (') Quoted String

“Hello Python”

# Double (") Quoted String

“”“Hello Python”“”

‘’‘Hello Python’‘’

# triple (‘’') (“”") Quoted String

In python, string handling is a straightforward task, and python provides various built-in functions and operators for representing strings.

The operator “+” is used to concatenate strings and “*” is used to repeat the string.

“Hello”+“python”

output**:****‘Hello python’**

"python "*****2

'Output : Python python ’

#python web development #data types in python #list of all python data types #python data types #python datatypes #python types #python variable type