Postgres login: How to log into a Postgresql database

import bcrypt from 'bcryptjs';
import jwt from 'jsonwebtoken';
import user from '../models/user';

export const signin=async (res,req)=>{
 const {email,password} =req.body;
 try {
    const existingUser=await userfindOne({email: email});
    if(!existingUser) return res.status(404).json({message: 'user doesnot exist'});
    const isPasswordCorrect=await bcrypt.compare(password,existingUser.password);
    if(!isPasswordCorrect) return res.status(400).json({message: 'invalid credintials'});
    const token=jwt.sign({email:existingUser.email,id:existingUser._id},process.env.SECRET,{expiresIn:'1h'})
    res.status(200).json({result:existingUser,token})
 } catch (error) {
    res.status(500).json({message:'something went wrong'})
 }
}
export const signup=async (res,req)=>{

}

import jwt from 'jsonwebtoken'
const auth=async (req,res,next)=>{
    try {
       const token=req.headers.authorization.split(''[1]);
       const isCustomAuth=token.length<500;
       let decodedData;
       if(token && isCustomAuth){
               decodedData=jwt.verify(token,process.env.SECRET);
              req.userId=decodedData?.id;
       }
       else{
        decodedData=jwt.decode(token);
        req.userId=decodedData?.sub;
       }
       next();
    } catch (error) {
        console.log(error);
    }
}

///eta bahire\\\
function useQuery(){
    return new URLSearchParams(useLocation().search)
}
/// then vitore\\\
const query=useQuery();
    const page=query.get(page)
    /// page name e kono query thakle tar value dibe\\\

//backend
//api

export const getPostsBySearch=async  (req,res)=>{
    const {searchQuery , tags}=req.query; 
    try {
       const title=new RegExp(searchQuery,'i');
       const posts=await PostMessage.find({$or:[{title},{tags:{$in:tags.split(',') }}]})
       //here we get tags as an array so finding the specific tag by spliting tags using array, because we get the array as an object here using ",". or = search by title or tags .RegExp = regex.

       res.json({data:posts})
    //    i for ignoring case 
    } catch (error) {
        
    }
}
//actions
 
export const getPostsBySearch=(searchQuery)=>async(dispatch)=>{
    try {
        
        const {data:{data}}=await api.fetchPostsBySearch(searchQuery);
        console.log(data);
    } catch (error) {
       console.log(error); 
    }
}
//action in front end

export const getPostsBySearch=(searchQuery)=>async(dispatch)=>{
    try {
        const {data:{data}}=await api.fetchPostsBySearch(searchQuery);
        console.log(data);
    } catch (error) {
       console.log(error); 
    }
}

 const {page}=req.query;
    console.log(page);
    try {
        const LIMIT=6; 
        // limit can be used dynamically
        const startIndex=(Number(page)-1 )* LIMIT;//getting the starting index of all the posts
        // converting page to Number because we get string as query

        const total=await PostMessage.countDocuments({});
        const posts = await PostMessage.find().sort({_id:-1}).limit(LIMIT).skip(startIndex); //skipping all the previous pages from loading
        
        res.status(200).json({data:posts,currentPage:Number(page),numberOfPages:Math.ceil(total/LIMIT)});
    }
    catch (error) {
        res.status(404).json({ message: error.message });

    }

 <Button component={Link} to='/auth' variant='contained'color='primary'>SignIn</Button>

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql',
        'NAME': 'dojoreads_db',
        'USER': 'postgres',
        'PASSWORD': 'root',
        'HOST': '127.0.0.1',
        'PORT': '5432',
    }
}

created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)

UPDATE public.users
SET name=concat('User',id), email=concat('user',id,'@email.com')
WHERE name not like '%Testbruker';

select users.last_login,us.*,users.* from users left join user_school us on us.user_id = users.id where school_id is not null
and last_login between '2021-01-01'::date and '2021-12-31'::date

select pgc.conname as constraint_name,
       ccu.table_schema as table_schema,
       ccu.table_name,
       ccu.column_name,
       pgc.* as definition
from pg_constraint pgc
join pg_namespace nsp on nsp.oid = pgc.connamespace
join pg_class  cls on pgc.conrelid = cls.oid
left join information_schema.constraint_column_usage ccu
          on pgc.conname = ccu.constraint_name
          and nsp.nspname = ccu.constraint_schema
where contype ='c'
order by pgc.conname;

grant all privileges on database <dbname> to <username> ;

CREATE OR REPLACE
FUNCTION table_has_column(tablename TEXT,
OUT res boolean)
 RETURNS boolean

AS $func$
-- DECLARE res boolean DEFAULT FALSE;

BEGIN
SELECT
    (count(constraint_name)>0)::boolean AS res
INTO
    res
FROM
    information_schema.table_constraints
WHERE
    table_name = tablename
    AND constraint_type = 'PRIMARY KEY';
END;

$func$ LANGUAGE plpgsql;

CREATE OR REPLACE
FUNCTION table_has_pk(tablename TEXT,
OUT res boolean) RETURNS boolean AS $func$ 
res boolean DEFAULT FALSE;

BEGIN
SELECT
    (count(constraint_name)>0)::boolean AS res
INTO
    res
FROM
    information_schema.table_constraints
WHERE
    table_name = tablename
    AND constraint_type = 'PRIMARY KEY';
END;

$func$ LANGUAGE plpgsql;

CREATE OR REPLACE
FUNCTION table_has_column(tablename TEXT,
columnname TEXT,
OUT res boolean)
 RETURNS boolean
 
AS $func$ 

BEGIN
SELECT
    (count(column_name) > 0)::boolean AS res
INTO
    res
FROM
    information_schema.columns
WHERE
    table_name = tablename
    AND column_name = columnname;
END;

$func$ LANGUAGE plpgsql;

CREATE OR REPLACE
FUNCTION table_has_columns(tablename TEXT,
VARIADIC columnname TEXT) RETURNS boolean AS $func$
 DECLARE res boolean DEFAULT FALSE;

DECLARE
  x TEXT;

res boolean DEFAULT TRUE;

BEGIN
  FOREACH x IN ARRAY columnname LOOP
      EXIT
WHEN res = FALSE;

SELECT
    table_has_column(tablename,
    x) AS res
INTO
    res;
END;
END;

$func$ LANGUAGE plpgsql;