HyperNetDatabase

M L Viñas Livschitz

Rate me:

4.11/5 (16 votes)

21 Mar 20044 min read

123.2K

819

HyperNetDatabase is a single process multithreading and blackout safe database

Sample Image - maximum width is 600 pixels

Introduction

This project was developed in order to help users that use databases like commercial ACCESS for small projects and then are subject to commercial laws. This is a simple solution for a database engine that can supply a good power to normal database tasks. This driver is free (GPL).

Using the code

Link the two DLLs HyperNetDatabase.DLL and NetFrmExts.DLL to your project and you'll be linked. Note use R2 Only, R1 is older and unstable.

To open a database and make a select:

using HyperNetDatabase.R2;
...
Database db = new Database();
db.Open("file.hnd"); // creates or opens database
...
..
DataTable result = db.Select(
    new string[]{"SEQNAME"}, // fields as an array of strings
    "$Sequences", // Name of the table
    new object[,]{ {"SEQNAME","=",myseq} } 
  // pairs of filter conditions : ... WHERE SEQNAME=myseq AND ...
    );
..
db.Close();

Public Static Methods

DataRow2NameAndValue Converts a DataRow in a NameAndValue object with skipRows.

Public Instance Constructors

Database Constructor

Default constructor

Public Instance Properties

`Filename`	Filename of the database
<IMG src="MlVlHyperNetDatabase/pubproperty.gif">Lock	Global lock, used to lock other thread to make concurrent queries. Example: Read and then insert.
<IMG src="MlVlHyperNetDatabase/pubproperty.gif">State	Connection state

Public Instance Methods

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">AddField

Adds a field

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">AddFieldIfNotExist

Adds a field if it not exists

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">AddTable

Adds a table

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">AddTableIfNotExist

Adds a table if it not exists

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Close

Closes a database

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Delete

SQL DELETE query <example>Example:

using HyperNetDatabase.R2;
...
Database db = new Database();
db.Open("file.hnd");
 // creates or opens database
...
string StockName = "peppers";
DataTable result = db.Delete("Stock",
new object[,]{ {"NAME","=",StockName} }
);
...

Is the same as: DELETE Stock WHERE NAME=@StockName

WHERE expression: Is an C# expresion for making a where as a filter.

new object[,]{ {"{FIELDNAME}",{operand},{parameter}},... } Is the same as "field operand parameter AND ..."
null Means the same as no where condition.

Operand	Effect
=	Equality
>	Value of left field name is greater than right constant value variable
>=	Value of left field name is greater or equal than right constant value variable
<	Value of left field name is less than right constant value variable
<=	Value of left field name is less or equal than right constant value variable
!=	Value of left field name is different than right constant value variable

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">DropTable

Removes a table

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">DropTableIfExists

Drops a table if the table exists

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Dump

Dumps pages state

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">ExistsTable

Returns true if the table exists

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">FlushIndexes

Destroys in memory indexes. Do this if your were walking for many tables and you memory resources are low.

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">ForcedInsert

Overloaded. More known as Update or Insert (Sets values by a keyfield) Inserts if the condition does not match or updates if the condition matches.<example>

db.ForcedInsert( "Stock", "NAME",
  "Peppers", "Qty", 0.5m );

Is the same as:

SQL

SELECT Count(*) FROM STOCK WHERE NAME="Peppers";
if count > 0 then
UPDATE STOCK SET Qty=0.5 WHERE NAME="Peppers";
else
INSERT INTO STOCK (NAME,Qty)
   VALUES ("Peppers",0.5);

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">ForcedSelect

Obtains a value and if it not exists obtains it's default value

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">GetTableNames

Gets all tables in this database

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">GetUserFields

Fields for users

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Insert

Inserts data into a Table <example>Example:

 using HyperNetDatabase.R2;
 ...
 Database db = new Database();
 db.Open("file.hnd");
  // creates or opens database
 ...
 string StockName = "peppers";
 DataTable result = db.Insert(
  "Stock", new object[,]
{ {"NAME",StockName}, {"QTY",0.5m} } );
 ...

Is the same as: INSERT INTO Stock (NAME,QTY) VALUES (@StockName,0.5);

SET expression: Is an C# expresion for indicate a FIELD with its VALUE.new object[,]{ {"{FIELDNAME}",{parameter}},... } Is the same as "SET field = parameter, ..."<example>Example 1:

new object[,]{ {"QTY",0.5m} }

<example>Example 2:

new object[,]{ {"STRNAME","peppers"},
 {"QTY",0.5m} }

LogToFile (inherited from LogSupport) Saves a string in the log file

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Open

Open

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">PreloadIndexes

Preloads indexes for table to make reads faster

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Select

SQL Select query. <example>Example:

using HyperNetDatabase.R2;
...
Database db = new Database();
db.Open("file.hnd"); // creates or opens database
...
string StockName = "peppers";
DataTable result = db.Select(null,"Stock",
new object[,]{ {"NAME","=",StockName} }
);
...
result = db.Select(new string[]{"NAME"},"Stock",
new object[,]{ {"NAME","=",StockName} }
);
...

Is the same as:

SELECT * FROM Stock WHERE NAME=@StockName
SELECT NAME FROM Stock WHERE NAME=@StockName

WHERE expression: Is an C# expresion for making a where as a filter.

new object[,]{ {"{FIELDNAME}", {operand},{parameter}},... } Is the same as "field operand parameter AND ..."
null Means the same as no where condition.

Operand	Effect
=	Equality
>	Value of left field name is greater than right constant value variable
>=	Value of left field name is greater or equal than right constant value variable
<	Value of left field name is less than right constant value variable
<=	Value of left field name is less or equal than right constant value variable
!=	Value of left field name is different than right constant value variable

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">seqCreate

Overloaded. Creates a sequence.

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">seqCurrentValue

Current sequence value

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">seqDrop

Sequence drop

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">seqExists

Sequence exists?

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">seqNextValue

Next sequence value (and autoincrement)

<IMG 
src="MlVlHyperNetDatabase/pubmethod.gif">Update

SQL UPDATE query <example>Example:

using HyperNetDatabase.R2;
...
Database db = new Database();
db.Open("file.hnd"); // creates or opens database
...
string StockName = "peppers";
DataTable result = db.Update("Stock",
new object[,]{ {"NAME",StockName}, {"QTY",0.5m} },
new object[,]{ {"NAME","=","pepperoni"} }
);
...

Is the same as: UPDATE Stock SET NAME=@StockName, QTY=0.5 WHERE NAME=pepperoni

WHERE expression: Is an C# expresion for making a where as a filter.

new object[,]{ {"{FIELDNAME}",{operand},{parameter}},... } Is the same as "field operand parameter AND ..."
null Means the same as no where condition.

Operand	Effect
=	Equality
>	Value of left field name is greater than right constant value variable
>=	Value of left field name is greater or equal than right constant value variable
<	Value of left field name is less than right constant value variable
<=	Value of left field name is less or equal than right constant value variable
!=	Value of left field name is different than right constant value variable

SET expression: Is an C# expresion for indicate a FIELD with its VALUE.

new object[,]{ {"{FIELDNAME}",{parameter}},... } is the same as "SET field = parameter, ..."

<example>Example 1:

new object[,]{ {"QTY",0.5m} }

<example>Example 2:

new object[,]{ {"STRNAME","peppers"},
 {"QTY",0.5m} }

Points of Interest

Support all SQL basic functions.
Additional features.
Protect from Blackouts
Multithreading-safe

History

RELEASE VERSION 2.0.0 NOTES - 2004-03-17

Features:

First stable version
Support all SQL basic functions.
Additional features.
Protect from Blackouts
Multithreading-safe

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

Written By

M L Viñas Livschitz

Web Developer

Spain

This member has not yet provided a Biography. Assume it's interesting and varied, and probably something to do with programming.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

HyperNetDatabase

Introduction

Using the code

Public Static Methods

Public Instance Constructors

Public Instance Properties

Public Instance Methods

Points of Interest

History

RELEASE VERSION 2.0.0 NOTES - 2004-03-17

Features:

License

Comments and Discussions