feat: refactor db handling to use db-wrapper package; enhance connection management and result handling for MSSQL and Postgres

internal/app/db-wrapper/mssql.go

@@ -15,15 +15,23 @@ func init() {
 }
 
 type mssqlRowResult struct {
+	row *sql.Row
+}
+
+func (mr *mssqlRowResult) Scan(dest ...any) error {
+	return mr.row.Scan(dest...)
+}
+
+type mssqlRowsResult struct {
 	columns []string
 	rows    *sql.Rows
 }
 
-func (mr *mssqlRowResult) Close() error {
+func (mr *mssqlRowsResult) Close() error {
 	return mr.rows.Close()
 }
 
-func (mr *mssqlRowResult) Columns() ([]string, error) {
+func (mr *mssqlRowsResult) Columns() ([]string, error) {
 	if mr.columns != nil {
 		return mr.columns, nil
 	}
@@ -31,19 +39,19 @@ func (mr *mssqlRowResult) Columns() ([]string, error) {
 	return mr.rows.Columns()
 }
 
-func (mr *mssqlRowResult) Err() error {
+func (mr *mssqlRowsResult) Err() error {
 	return mr.rows.Err()
 }
 
-func (mr *mssqlRowResult) Next() bool {
+func (mr *mssqlRowsResult) Next() bool {
 	return mr.rows.Next()
 }
 
-func (mr *mssqlRowResult) Scan(dest ...any) error {
+func (mr *mssqlRowsResult) Scan(dest ...any) error {
 	return mr.rows.Scan(dest...)
 }
 
-func (mr *mssqlRowResult) Values() ([]any, error) {
+func (mr *mssqlRowsResult) Values() ([]any, error) {
 	columns, err := mr.Columns()
 	if err != nil {
 		return nil, err
@@ -112,7 +120,12 @@ func (mw *mssqlDbWrapper) Query(ctx context.Context, query string, args ...any)
 		return nil, err
 	}
 
-	return &mssqlRowResult{columns: nil, rows: rows}, nil
+	return &mssqlRowsResult{columns: nil, rows: rows}, nil
+}
+
+func (mw *mssqlDbWrapper) QueryRow(ctx context.Context, query string, args ...any) RowResult {
+	row := mw.db.QueryRowContext(ctx, query, args...)
+	return &mssqlRowResult{row: row}
 }
 
 func (mw *mssqlDbWrapper) SaveMassive(ctx context.Context, schema string, table string, columnNames []string, rows [][]any) (int64, error) {