Description:

sql transformer

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

SqlSplitterTransformer. Splits a stream of SQL statements into a stream of individual SQL statements.
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;
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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));
}


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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());
}
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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'}));
}
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License #
BSD 3-Clause License (see LICENSE file)

License

For personal and professional use. You cannot resell or redistribute these repositories in their original state.

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