DbUtility

DbUtility is a light database access tool

How to use

execute a query

db.T( "SELECT * FROM Members" ).ExecuteDataTable();

execute a query with parameter and return first row

db.T( "SELECT FirstName, LastName FROM Members WHERE Username = {0}", username ).ExecuteFirstRow();

execute a query as async.

await db.T( "SELECT FirstName, LastName FROM Members WHERE Username = {0}", username ).ExecuteFirstRowAsync();

Basic concept

db.T( "SELECT FirstName, LastName FROM Members WHERE Username = {0}", username ).ExecuteFirstRow();

In the code above, db is called database executor,
T( "SELECT FirstName, LastName FROM Members WHERE Username = {0}", username ) is called query definition,
and ExecuteFirstRow() is called result definition

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The following code creates a database executor

var db = SqlServer.FromConfiguration( "connection-string-name" );

Or

var db = SqlServer.Connect( "connection-string" );

database executor is responsible for createing connection and executing queries.

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A typical query definition like this below

db.T( "query-text-template", params parameters );

The query text is SQL command to be executed. and you can use parameter placehold inside like string.Format syntax. like this below:

db.T( "SELECT MemberID FROM Members WHERE Username = {0} AND Password = {1}", username, password )

it will create a SQL query like this below:

DECLARE @Param0 AS nvarchar = 'text of username';
DECLARE @Param1 AS nvarchar = 'text of password';
SELECT MemberID FROM Members WHERE Username = @Param0 AND Password = @Param1;

the method name T means Template, so we can also write code like below:

db.Template( "SELECT MemberID FROM Members WHERE Username = {0} AND Password = {1}", username, password )

and the T is an extension method, you can customize another query definition method as you like.

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In the end, we talk about the result definition. like same as the query definition, result definition are also en extension method. we have many result definition method, and all of they have asynchronous version. the popular result definition method under this:

ExecuteNonQuery, execute query, and return the number of rows affected.
ExecuteScaler, execute query and return the first column of the first row.
ExecuteDataTable, execute query and fill a DataTable and return.
ExecuteFirstRow, execute query and return ths first row.
ExecuteEntity, execute query and return the first row to fill the specified type of entity
and more, and customize as you like