OneQuery

COMMENTED FEATURE: Support for DELETE Statements

openarrow — Sun, 16 Dec 2007 22:09:01 GMT

Support for DELETE Statements should be added to OneQuery.
Comments: Associated with changeset 14547.

COMMENTED FEATURE: Support for UPDATE Statements

openarrow — Sun, 16 Dec 2007 22:09:01 GMT

Support for UPDATE Statements should be added to OneQuery
Comments: Associated with changeset 14547.

COMMENTED FEATURE: Support for INSERT Statements

openarrow — Sun, 16 Dec 2007 22:09:00 GMT

Support for INSERT statements should be added to OneQuery
Comments: Associated with changeset 14547.

Source code checked in

openarrow — Sun, 16 Dec 2007 22:08:58 GMT

Added initial work on INSERT, UPDATE, DELETE

UPDATED WIKI: Home

openarrow — Thu, 13 Dec 2007 02:04:50 GMT

More Info
Check out Andrew's personal blog for more information and updates.

Project Description

One Query, Any Database - Write one Query and have it run on multiple Database Engines. OneQuery is a Database-agnostic query engine that focuses on allowing developers to write queries that will run on multiple database engines. It is not an Object/Relational Mapper, at least not in its current incarnation.

December 2007 Preview Release

The December 2007 Preview Release has been posted. This version contains a working query engine that supports simple queries of the form "SELECT * FROM Table WHERE Conditions ORDER BY Columns". Download it, try it out and discuss it in the Discussions section.

Syntax

OneQuery uses a Fluent Interface to provide a simple, but powerful, query tool. The current release only supports simple SELECT queries, but there are plans to support INSERT, UPDATE and DELETE commands in the next release and more advanced queries as time moves on.

Examples

Common Code
The code below creates a class containing some helper fields. In the next few releases I'm hoping to develop a code generator that will create this for you. Of course, if anyone wants to contribute some time to work on that, please post in the Discussions section :).

public class Products
{
    public static readonly ColumnReference UnitPrice = new ColumnReference(Table, "UnitPrice")
    // ... repeat for each column in the table
    public const string Table = "Products"
    public static Query Query() { return Query.From(Table); }
}

"Fetch All" Query
The following query retrieves all records from a table in the database and returns an IDataReader containing those records.

IDataReader rdr = Products.Query().ExecuteReader();

"Fetch By ID" Query
The following query retrieves a specific record by its ID (in this case 4), and returns an IDataReader containing the record.

IDataReader rdr = Products.Query().Where(Products.ProductID == 4).ExecuteReader()

"Fetch By Conditions" Query
The following query retrieves all records matching a set of conditions and returns an IDataReader containing the records.

IDataReader rdr = Products.Query().Where(Products.UnitPrice > 10 & Products.UnitPrice < 20).ExecuteReader()

Operator Overloading

As the examples above show, Operator Overloading is a key part of the cleanliness of the interface. However, there is one important note to be made: The "&&" and "||" operators should NOT be used in OneQuery expressions since the short-circuit evalutation features may cause issues during query translation. Instead, the "&" and "|" operators will have the same effect.

CREATED FEATURE: Support for DELETE Statements

openarrow — Wed, 12 Dec 2007 05:07:27 GMT

Support for DELETE Statements should be added to OneQuery.

CREATED FEATURE: Support for UPDATE Statements

openarrow — Wed, 12 Dec 2007 05:06:31 GMT

Support for UPDATE Statements should be added to OneQuery

CREATED FEATURE: Support for INSERT Statements

openarrow — Tue, 11 Dec 2007 17:38:42 GMT

Support for INSERT statements should be added to OneQuery

CREATED FEATURE: Support for SELECT Expressions

openarrow — Tue, 11 Dec 2007 05:49:01 GMT

SELECT Query support already exists in the current system, but it only supports "SELECT *" queries. Support for SELECT Expressions (such as Column Names, Aggregates, Functions, Aliases, etc.) should be added to the existing support.

CREATED FEATURE: Simple Code Generator

openarrow — Tue, 11 Dec 2007 05:46:46 GMT

In order to speed up development time, a code generator that generates the helper "Schema Classes" would be useful. The tool could be pointed at a database and would produce a class like this:

public class Table
{
    public static readonly ColumnReference Column1 = new ColumnReference(TableName, "Column1");
    public static readonly ColumnReference Column2 = new ColumnReference(TableName, "Column2");
    ...
    public const string TableName = "Table";
    public static Query Query() { return Query.From(TableName); }
}

UPDATED WIKI: Home

openarrow — Tue, 11 Dec 2007 05:30:51 GMT

Project Description

December 2007 Preview Release

Syntax

Examples

public class Products
{
    public static readonly ColumnReference UnitPrice = new ColumnReference(Table, "UnitPrice")
    // ... repeat for each column in the table
    public const string Table = "Products"
    public static Query Query() { return Query.From(Table); }
}

"Fetch All" Query
The following query retrieves all records from a table in the database and returns an IDataReader containing those records.

IDataReader rdr = Products.Query().ExecuteReader();

"Fetch By ID" Query
The following query retrieves a specific record by its ID (in this case 4), and returns an IDataReader containing the record.

IDataReader rdr = Products.Query().Where(Products.ProductID == 4).ExecuteReader()

"Fetch By Conditions" Query
The following query retrieves all records matching a set of conditions and returns an IDataReader containing the records.

IDataReader rdr = Products.Query().Where(Products.UnitPrice > 10 & Products.UnitPrice < 20).ExecuteReader()

Operator Overloading

UPDATED WIKI: Home

openarrow — Tue, 11 Dec 2007 05:30:02 GMT

Project Description

December 2007 Preview Release

Syntax

Examples

public class Products
{
    public static readonly ColumnReference UnitPrice = new ColumnReference(Table, "UnitPrice")
    // ... repeat for each column in the table
    public const string Table = "Products"
    public static Query Query() { return Query.From(Table); }
}

"Fetch All" Query
The following query retrieves all records from a table in the database and returns an IDataReader containing those records.

IDataReader rdr = Products.Query().ExecuteReader();

"Fetch By ID" Query
The following query retrieves a specific record by its ID (in this case 4), and returns an IDataReader containing the record.

IDataReader rdr = Products.Query().Where(Products.ProductID == 4).ExecuteReader()

"Fetch By Conditions" Query
The following query retrieves all records matching a set of conditions and returns an IDataReader containing the records.

IDataReader rdr = Products.Query().Where(Products.UnitPrice > 10 & Products.UnitPrice < 20).ExecuteReader()

Operator Overloading

CREATED RELEASE: December 2007 Preview (Dec 10, 2007)

Tue, 11 Dec 2007 05:10:02 GMT

This is the December 2007 Preview release. Featureset is a bit light, but its a start. Download it, try it out, and contribute to the development by posting feature requests and asking questions!

Source code checked in

openarrow — Tue, 11 Dec 2007 05:01:12 GMT

Updated AssemblyInfo.cs

Source code checked in

openarrow — Tue, 11 Dec 2007 05:01:12 GMT

Updated AssemblyInfo.cs

Source code checked in

openarrow — Tue, 11 Dec 2007 04:56:35 GMT

Fixed DatabaseServiceTests

Source code checked in

openarrow — Tue, 11 Dec 2007 04:39:25 GMT

* Removed overloads of ExecuteReader/Scalar/NonQuery from Command * Removed OneQueryConfigurationSectionGroup * Added XML Doc Comments

Source code checked in

openarrow — Tue, 11 Dec 2007 00:12:49 GMT

* Minor Configuration Tweaks * Added support for ORDER BY * Tweaked TestApp to demonstrate current functionality

Source code checked in

openarrow — Mon, 10 Dec 2007 08:40:33 GMT

Changed thrown ConfigurationException to new EngineInitializationException and configured project to treat warnings as errors

UPDATED WIKI: Home

openarrow — Mon, 10 Dec 2007 08:30:08 GMT

Project Description
One Query, Any Database - Write one Query and have it run on multiple Database Engines. OneQuery is a Database-agnostic query engine that focuses on allowing developers to write queries that will run on multiple database engines. It is not an Object/Relational Mapper!

UPDATE
I'm getting close to a release now. I've been working on Unit Tests and the last few features over this weekend. No promises, but I think I'll have something ready early this week. Once the initial release is going, I'm going to write up a few tutorials and then start using the Issue Tracker to plan the next steps, feel free to ask any questions in the Discussions section!

Syntax
So, I'm getting close to having some form of working system, though it won't be much. I've got support for generating SQL Server queries for simple "SELECT * FROM tableName WHERE conditions" queries. Here's some sample code to wet your appetite :)

// First, some helpful static methods/fields. Eventually there will be a codegen tool for this
public class Products
{
    public static readonly ColumnReference UnitPrice = new ColumnReference("UnitPrice");
    public static Query Query() { return Query.From("Products"); }
}
 
// .. snipped out the boilerplate console application code ...
 
IDataReader rdr = Products.Where(Products.UnitPrice > 10 & Products.UnitPrice < 20).ExecuteReader();
while(rdr.Read())
    Console.WriteLine("Price of {0} is between 10 and 20", rdr["ProductName"]);
 
// .. end ..

The exact code may change before I release it, but this kind of functionality will be working in the upcoming v0.1 release. The next step will be working in "SELECT Expressions" so that you aren't forced to use "SELECT *", you could use more complex expressions like "SELECT MAX(UnitPrice) AS 'MaxPrice'" or just "SELECT Foo, Bar, Baz FROM Table". I see the code looking something like this:

Query qry = Products.Where(Products.UnitPrice > 10).Select(Products.UnitPrice.Max)
Query qry = Products.Where(...).Select(Products.ProductID, Products.ProductName, Products.UnitPrice.As("MyUnitPrice"))

From there I hope to add support for JOINs, GROUP BY and more!

Note
OneQuery is still in early development, but feel free to check out the code that's available in the Source Code section and ask questions in the Discussions section!