sql_transformer 0.0.4

Dart package with useful transformers for SQL queries. Splitting SQL statements from a single file, and replacing variables in them.

SQL Transformer

Useful transformers to be used with Dart's streams when reading SQL files.

At the time of this writing, there are only two available SQL transformers

1. SqlSplitterTransformer. Splits a stream of SQL statements into a stream of individual SQL statements.
2. SqlValuesTransformer. Replaces all values in a stream of SQL statements with a question mark.

Usage

Replacing / setting values to variables in SQL files

To do this, you must use the SqlValuesTransformer class, and pass as an argument a map with the values you'd like to replace.

For using and replacing variables with the transformer, you must use the SqlValuesTransformer class, and pass as an argument a map with the values you'd like to replace. For this to work, you must use the colon in front of the variable name in the SQL file.

Example SQL file:

select * from users where name = :name and last_name = :last_name;

Example Dart code:

import 'dart:convert';
import 'dart:io';

import 'package:sql_transformer/sql_transformer.dart';

void main(List<String> args) async {
  final file = File('get_users_and_purchases.sql');
  // The values you'd like to replace in the SQL file.
  final values = {'name': 'John', 'last_name': 'Doe'};

  final lines = utf8.decoder
      .bind(file.openRead())
      .transform(const SqlValuesTransformer(values));
  }
  

Splitting SQL file into individual SQL statements

import 'dart:convert';
import 'dart:io';

import 'package:sql_transformer/sql_transformer.dart';

void main(List<String> args) async {
  var file = File('get_users_and_purchases.sql');
  var lines = utf8.decoder
      .bind(file.openRead())
      .transform(const SqlSplitterTransformer());
}

You can also chain the transformers together

import 'dart:convert';
import 'dart:io';

import 'package:sql_transformer/sql_transformer.dart';

void main(List<String> args) async {
  var file = File('example.sql');
  var lines = utf8.decoder
      .bind(file.openRead())
      .transform(const SqlSplitterTransformer())
      .transform(const SqlValuesTransformer({'name': 'John', 'last_name': 'Doe'}));
}

License

BSD 3-Clause License (see LICENSE file)