sonus21

func doesOrderExist(ctx context.Context, db *sql.DB, req *OrderCreateRequest) (bool, error) {
	cntResult := db.QueryRowContext(ctx, "SELECT COUNT(id) from orders WHERE merchant_id=? AND merchant_order_id=?", req.MerchantId, req.MerchantOrderId)
	err := cntResult.Err()
	if err != nil {
		return false, err
	}
	var count int
	err = cntResult.Scan(&count)
	if err != nil {
		return false, err

sonus21

// determineDbName this method is used to determine the actual database name from request method and path
// here more complex logic can be placed like for this path, path regex, header parameters etc
func determineDbName(method, path string, header http.Header) string {
	if method == http.MethodGet {
		return Secondary
	}
	// add any other logic
	return Primary
}

sonus21

// Middleware a middleware that is used in chi to set the database context
func Middleware() func(next http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		fn := func(w http.ResponseWriter, r *http.Request) {
			// identify database name from request
			name := dbNameFromRequest(r)
			// set db name in the context
			ctx := SetDb(r.Context(), name)
			// call next handler with database context
			next.ServeHTTP(w, r.WithContext(ctx))

sonus21

const (
	_dbCtxKey = "DBCtx"
)

var (
	_dbs       map[string]*sql.DB
	_defaultDB string
)

// Init initialize the database context internal state

sonus21

// MySqlConfig this is used to store the different MySQL configuration
type MySqlConfig struct {
	Host                 string
	Port                 int
	Database             string
	Username             string
	Password             string
	MaxConnectionRetries int
	MaxOpenConnection    int
	MaxIdleConnection    int

sonus21

from .constants import SECONDARY, PRIMARY
from CoreApp.middlewares import db_wrapper


@db_wrapper(PRIMARY)
def reserve_driver(request):
    # logic goes here
    pass

sonus21

from functools import wraps

from .utils import db_from_the_request
from .db_router import set_db_for_router, clear_db_for_router


class DatabaseMiddleware(object):
    """
    DatabaseMiddleware sets the db in the thread local context and used
    across multiple calls to handle the DB calls.

sonus21

INSTALLED_APPS = [
    # ...
    "CoreApp"
    # ...
]



MIDDLEWARE = [

sonus21

import threading

threadLocal = threading.local()


def get_current_db_name():
    return getattr(threadLocal, "DB", None)


def set_db_for_router(db):

sonus21

def _determine_db_name(method, path):
    # If you have multiple read databases, you can use DNS to direct them to one database.
    # Alternatively, you can randomly select a database from the list if you prefer not to
    # use DNS.
    if method in ["GET"]:
        return SECONDARY
    # in many cases POST method can be read only as well
    # and in some cases GET method can be performing CUD operations as well
    # in these cases we can add a check on the path
    return PRIMARY