Recently completed a small hospital information automation management system, I want to write a summary of this development. Because it was developed from the first time, some places wrote a little naive. If there is an incorrect place, please ask your high-end fingertips!
Let me talk about my overall development process.
1. According to the system's expected function, first create a good database. Now the entire project is completely completed, and the total feelings are very important for the database establishment.
2. Write a DataAccess (data layer). The code is accurate and can't bring trouble for later development.
3. Write the businessRules (Business Layer) based on the specific function. My idea is to return a DataSet from DataAccess, then accept this DataSet in the function block in the specific business layer, create a DataTable in BusinessRules, populate DataSet into the DataTable, and then return to DataTable. For Indicates the layer to use the DataTable it needs.
4. Return to the design on the interface based on the pre-thoughtable function. Since I am very poor, the interface is very general, just dragging the control.
The expected features are 3 parts, namely: outpatient management, hospital equipment management and pharmacy management.
From 3 to the functional requirements of the database: employees, patients, equipment, departments, department, ward, bed, outpatient business. Attributes and relational tables associated with these entities. Now the database is built! Then start writing the data layer (DataAccess), the program is as follows:
1. A class that gets the connection string.
Public Class Constr
Private constr as string
Public Sub New ()
Constr = "Server = localhost; database = The hospital message manager; user ID = sa; password =;"
End Sub
Public function getconstr () AS String
GetConstr = constr
END FUNCTION
END CLASS
2. A database operation class with returning plants, ie query.
Imports system.data.sqlclient
Public Class Querydata
'This function is an operation of the SQL statement.
Public Function QueryDataInsentence (Byval Sqlstr As String) AS Dataset
DIM Constr As New Constr
Dim Adpter AS New SqldataAdapter
DIM DS AS New DataSet
DIM COM AS New SQLCommand
DIM Con As New SqlConnection (Constr.getConstr)
Adpter.selectCommand = COM
Adpter.selectCommand.connection = con
Adpter.selectCommand.commandType = CommandType.Text
Adpter.selectCommand.comMandText = SQLSTR
Con.open ()
Try
Adpter.Fill (DS)
Return DS
Catch exception
MSGBOX (ex.Message)
Finally
Con. close ()
END TRY
END FUNCTION
'This function is a pair of stored procedures.
Public Function QueryDataInProc (Byval Sqlprocname As String) AS Dataset
DIM Constr As New Constr
Dim Adpter AS New SqldataAdapter
DIM DS AS New DataSet
DIM COM AS New SQLCommand
DIM Con As New SqlConnection (Constr.getConstr)
Adpter.selectCommand = COM
Adpter.selectCommand.connection = con
Adpter.selectcommand.commandtype = commandtype.storedProcedure
Adpter.selectCommand.commandtext = SQLPROCNAME
Con.open ()
Try
Adpter.Fill (DS)
Return DS
Catch exception
MSGBOX (ex.Message)
Finally
Con. close ()
END TRY
END FUNCTION
END CLASS
3. A data operation class that has not returned values, ie fills, deletes, and modifications. Because the needs of the program, the method in this class has a boolean return value.
Imports system.data.sqlclient
Public Class Unquerydata, PUBLIC CLASS UNQUERYDATA
'This function is an operation of the SQL statement.
Public Function Changeinsence (Byval Sqlstr As String) AS Boolean
DIM Constr As New Constr
DIM COM AS New SQLCommand
DIM Con As New SqlConnection (Constr.getConstr)
com.connection = con
com.CommandType = commandtype.text
com.commandtext = SQLSTR
Con.open ()
Try
com.executenonquery ()
Return True
Catch exception
Return False
MSGBOX (ex.Message)
Finally
Con. close ()
END TRY
END FUNCTION
'This function is a pair of stored procedures.
Public Function ChangeinProc (Byval SqlProcname As String) AS Boolean
DIM Constr As New Constr
DIM COM AS New SQLCommand
DIM Con As New SqlConnection
com.connection = con
com.commandtype = commandtype.storedProcedure
com.commandtext = SQLPROCNAME
Con.open ()
Try
com.executenonquery ()
Return True
Catch exception
Return False
MSGBOX (ex.Message)
Finally
Con. close ()
END TRY
END FUNCTION
END CLASS
The operation of the data layer mainly pays attention to the life cycle of each SqlClient object. In order not to enable the BusinessRules layer to access this layer, I will define the definition of no objects in the method, so that the life cycle of the object is very short.
