fixed account query to change the updateAccount func

db/query/account.sql

@@ -1,21 +1,40 @@
 -- name: CreateAccount :one
-insert into accounts(
+INSERT INTO accounts (
   owner,
   balance,
   currency
-)values( 
-$1,$2,$3
+) VALUES (
+  $1, $2, $3
 ) RETURNING *;
 
-
 -- name: GetAccount :one
-select * from accounts where id=$1 limit 1;
+SELECT * FROM accounts
+WHERE id = $1 LIMIT 1;
+
+-- name: GetAccountForUpdate :one
+SELECT * FROM accounts
+WHERE id = $1 LIMIT 1
+FOR NO KEY UPDATE;
 
 -- name: ListAccounts :many
-select * from accounts order by id limit $1 offset 2;
+SELECT * FROM accounts
+WHERE owner = $1
+ORDER BY id
+LIMIT $2
+OFFSET $3;
+
+-- name: UpdateAccount :one
+UPDATE accounts
+SET balance = $2
+WHERE id = $1
+RETURNING *;
 
--- name: UpdateAccount :exec
-update accounts set balance= $2 where id =$1;
+-- name: AddAccountBalance :one
+UPDATE accounts
+SET balance = balance + sqlc.arg(amount)
+WHERE id = sqlc.arg(id)
+RETURNING *;
 
 -- name: DeleteAccount :exec
-delete from accounts where id = $1;
+DELETE FROM accounts
+WHERE id = $1;

db/sqlc/store.go

@@ -60,6 +60,8 @@ func (store *Store) TransferTX(ctx context.Context, arg TransferTXParams) (Trans
 
 	err := store.execTX(ctx, func(q *Queries) error {
 		var err error
+
+		// create transfer record
 		result.Transfer, err = q.CreateTransfer(ctx, CreateTransferParams{
 			FromAccountID: arg.FromAccountID,
 			ToAccountID:   arg.ToAccountID,
@@ -68,22 +70,55 @@ func (store *Store) TransferTX(ctx context.Context, arg TransferTXParams) (Trans
 		if err != nil {
 			return err
 		}
+
+		// substract money from 'Fromaccount/senders account'
 		result.FromEntry, err = q.CreateEntry(ctx, CreateEntryParams{
 			AccountID: arg.FromAccountID,
 			Amount:    -arg.Amount,
 		})
 		if err != nil {
 			return err
 		}
+
+		// Add money to 'ToAccount/reciever's account'
 		result.ToEntry, err = q.CreateEntry(ctx, CreateEntryParams{
 			AccountID: arg.ToAccountID,
 			Amount:    arg.Amount,
 		})
 		if err != nil {
 			return err
 		}
+
 		// TODO: create update account and implement locking mechanism to handle deadlock
 
+		// transfer/move money from account 1
+		account1, err := q.GetAccount(ctx, arg.FromAccountID)
+		if err != nil {
+			return nil
+		}
+
+		result.FromAccount, err = q.UpdateAccount(ctx, UpdateAccountParams{
+			ID:      arg.FromAccountID,
+			Balance: account1.Balance - arg.Amount,
+		})
+		if err != nil {
+			return err
+		}
+
+		// add money to account 2
+		account2, err := q.GetAccount(ctx, arg.FromAccountID)
+		if err != nil {
+			return nil
+		}
+
+		result.ToAccount, err = q.UpdateAccount(ctx, UpdateAccountParams{
+			ID:      arg.ToAccountID,
+			Balance: account2.Balance + arg.Amount,
+		})
+		if err != nil {
+			return err
+		}
+
 		return nil
 	})
 	return result, err