Generate C# Class Code for Table in Visual Studio

Question

I have multiple tables in my Server Explore database file. I want to generate auto code of Classes for tables, so all classes with their attributes, constructor and getter setter methods automatically generate.

Kindly tell me steps to do so.

Answer 1

Not autogenerate, but it's not hard to use sql and information_schema to output a class definition, with the class named after the table and the columns being mappped to properties. From there you can have it generate create, updates and deletes (I like to use merge for crate/updates under SQL Server 2008).

Do them one at a time and it's mainly string concatination. The below should get you started....

declare @class varchar(max);

; with typemapping as (
 Select 'varchar' as DATA_TYPE, 'string' ctype
 union
 Select 'int', 'int'
)
select @class = isnull(@class + char(10), '') + 'public ' +
       tm.ctype +' ' + column_name +
       ' { get; set; }'
from information_schema.columns sc
   inner join typemapping tm on sc.data_type = tm.data_type
where table _name ='yourtbl'

print @class;

The rest is left as an exercise for the reader as they say mainly because the details are up to you, instead of auto properties you could use backing variables, put standard logic in the properties, make the value types nullable, when making your own code generator, make it fit your patterns/styles/needs.

Answer 2

If you use Entity Framework check the steps this article:

Generating EF Code First model classes from an existing database

Answer 3

I have modified the class above and included all missing methods

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;

using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Data.SqlClient;
using System.Configuration;
using System.Data.Common;

namespace CodeGenerator

{
    public partial class Form1 : Form
    {

    public Form1()
    {
        InitializeComponent();
    }

    private void btnGenerateCode_Click(object sender, EventArgs e)
    {
        string conStrJobsDB = ConfigurationSettings.AppSettings["jobsDBConStrKey"].ToString();
        CreateEntitiesFromDBTables(GetDataReader(conStrJobsDB));
    }

    private void CreateEntitiesFromDBTables(SqlDataReader dr)
    {
        if (dr != null)
        {
            string lstrOldTableName = string.Empty;
            StreamWriter swClassWriter = null;
            System.Text.StringBuilder sbFileName = null;
            System.Text.StringBuilder sbConstructorCode = null;
            System.Text.StringBuilder sbClassCode = null;
            FileInfo tableClassFile = null;

            while (dr.Read())
            {
                string lstrTableName = dr.GetString(0);
                string lstrAttributeName = dr.GetString(1);
                string lstrAttributeType = GetDotNetType(dr.GetString(2));

                //If table name is changed...
                if (lstrOldTableName != lstrTableName)
                {
                    //and stream writer is already opened so close this class generation...
                    if (swClassWriter != null)
                    {
                        CreateClassBottom(swClassWriter);
                        swClassWriter.Close();
                    }

                    sbFileName = new System.Text.StringBuilder(lstrTableName);
                    sbFileName.Append("Entity.cs");
                    tableClassFile = new FileInfo(tbPath.Text + "\\" + sbFileName.ToString());
                    swClassWriter = tableClassFile.CreateText();
                    CreateClassTop(swClassWriter, lstrTableName);

                    //sbConstructorCode = new System.Text.StringBuilder("\r\n\t/// \r\n\t" +
                    //     "/// User defined Contructor\r\n\t/// \r\n\tpublic ");
                    //sbConstructorCode = new System.Text.StringBuilder();
                    //sbConstructorCode.Append(lstrTableName);
                    //sbConstructorCode.Append("(");
                }
                else
                {
                    this.CreateClassBody(swClassWriter, lstrAttributeType, lstrAttributeName);
                    //sbConstructorCode.AppendFormat("{0} {1}, \r\n\t\t",
                    //   new object[] { lstrAttributeType, lstrAttributeName });
                    //sbConstructorCode.AppendFormat("\r\n\t\tthis._{0} = {0};",
                    //   new object[] { lstrAttributeName });
                }

                lstrOldTableName = lstrTableName;
                this.pBarMain.Increment(1);
            }

            MessageBox.Show("All classes generated.", "Done");
        }
    }

    private SqlDataReader GetDataReader(string conStrJobsDB)
    {
        SqlConnection connection = null;
        try
        {
            connection = new SqlConnection(conStrJobsDB);
            if (connection == null)
                return null;
            connection.Open();
            SqlCommand command = new System.Data.SqlClient.SqlCommand("exec spGenerateEntitiesFromTables", connection);
            SqlDataReader dr = command.ExecuteReader();
            if (dr.HasRows)
                return dr;
            else
                return null;
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
            return null;
        }
    }

    private string GetDotNetType(string dbColumnType)
    {
        string returnType = string.Empty;
        if (dbColumnType.Equals("nvarchar"))
            returnType = "string";
        else if (dbColumnType.Equals("varchar"))
            returnType = "string";
        else if (dbColumnType.Equals("int"))
            returnType = "int";
        else if (dbColumnType.Equals("bit"))
            returnType = "bool";
        else if (dbColumnType.Equals("bigint"))
            returnType = "long";
        else if (dbColumnType.Equals("binary"))
            returnType = "byte[]";
        else if (dbColumnType.Equals("char"))
            returnType = "string";
        else if (dbColumnType.Equals("date"))
            returnType = "DateTime";
        else if (dbColumnType.Equals("datetime"))
            returnType = "DateTime";
        else if (dbColumnType.Equals("datetime2"))
            returnType = "DateTime";
        else if (dbColumnType.Equals("datetimeoffset"))
            returnType = "DateTimeOffset";
        else if (dbColumnType.Equals("decimal"))
            returnType = "decimal";
        else if (dbColumnType.Equals("float"))
            returnType = "float";
        else if (dbColumnType.Equals("image"))
            returnType = "byte[]";
        else if (dbColumnType.Equals("money"))
            returnType = "decimal";
        else if (dbColumnType.Equals("nchar"))
            returnType = "char";
        else if (dbColumnType.Equals("ntext"))
            returnType = "string";
        else if (dbColumnType.Equals("numeric"))
            returnType = "decimal";
        else if (dbColumnType.Equals("nvarchar"))
            returnType = "string";
        else if (dbColumnType.Equals("real"))
            returnType = "double";
        else if (dbColumnType.Equals("smalldatetime"))
            returnType = "DateTime";
        else if (dbColumnType.Equals("smallint"))
            returnType = "short";
        else if (dbColumnType.Equals("smallmoney"))
            returnType = "decimal";
        else if (dbColumnType.Equals("text"))
            returnType = "string";
        else if (dbColumnType.Equals("time"))
            returnType = "TimeSpan";
        else if (dbColumnType.Equals("timestamp"))
            returnType = "DateTime";
        else if (dbColumnType.Equals("tinyint"))
            returnType = "byte";
        else if (dbColumnType.Equals("uniqueidentifier"))
            returnType = "Guid";
        else if (dbColumnType.Equals("varbinary"))
            returnType = "byte[]";

        return returnType;
    }

    private void CreateClassTop(StreamWriter sw, string lstrTableName)
    {
        System.Text.StringBuilder sb = null;
        sb = new StringBuilder("public class " + lstrTableName +"Entity\n{");
        sw.Write(sb.ToString());
    }

    private void CreateClassBody(StreamWriter sw, string lstrAttributeType, string lstrAttributeName)
    {
        System.Text.StringBuilder sb = null;
        sb = new StringBuilder("\n\rpublic " + lstrAttributeType + " " + lstrAttributeName + " { get; set; }");
        sw.Write(sb.ToString());
    }

    private void CreateClassBottom(StreamWriter sw)
    {
        System.Text.StringBuilder sb = null;
        sb = new StringBuilder("\n\n}");
        sw.Write(sb.ToString());
    }



}

}

Answer 4

you could try something like this...

Create one main class with the name ModelCreator.cs that does all the key operations. Entry point to this application is the Connect and Create button click event. It will fire a CreateConnectionString() method, which basically gets the input from the user and dynamically creates the connection string

private void lbtnConnect_Click(object sender, System.EventArgs e)
{
   if (CreateConnectionString())
  CreateModelClassFiles(tcGetDataReader());
}

// <summary>
/// Get the SqlDataReader object
/// SqlDataReader
/// </summary>

public SqlDataReader tcGetDataReader()
{
SqlConnection connection = null;
try
{
  connection = GetConnection(SQL_CONN_STRING);
  if (connection == null)
  return null;
  SqlDataReader dr = SqlHelper.ExecuteReader(
         connection,
         CommandType.StoredProcedure,
         "getData");
if (dr.HasRows)
  return dr;
else
  return null;
 }
 catch(Exception ex)
 {
  MessageBox.Show(ex.Message);
  return null;
 }   
}

Get Table Names, Attributes and their types from the database

 CREATE PROCEDURE getData AS 
 select table_name, column_name, data_type
  from information_schema.columns
  where table_name in
  (
   select table_name
   from Information_Schema.Tables
   where Table_Type='Base Table'
  ) order by table_name
GO

Main Method, CreateModelClassFiles

  /// <summary>
 /// Create the Model class list iterating through the tables
/// </summary>
/// <param name="dr">Sql Data reader for the database schema</param>

    private void CreateModelClassFiles(SqlDataReader dr)
    {
     if (dr != null)
    {
    string lstrOldTableName = string.Empty;
    StreamWriter sw = null;
    System.Text.StringBuilder sb = null;
    System.Text.StringBuilder sbAttr = null;
    while(dr.Read())
    {
      string lstrTableName = dr.GetString(0);
      string lstrAttributeName = dr.GetString(1);
      string lstrAttributeType = GetSystemType(dr.GetString(2));
      if (lstrOldTableName != lstrTableName)
      {
        if (sw != null)
        {
          this.CreateClassBottom(sw, sb.ToString().TrimEnd(
                     new char[]{',', ' ', '\r', '\t', '\n'}),
                     sbAttr.ToString());
            sw.Close();
        }
        sb = new System.Text.StringBuilder(lstrTableName);
        sb.Append(".cs");
        FileInfo lobjFileInfo = new FileInfo(sb.ToString());
        sw = lobjFileInfo.CreateText();
        this.CreateClassTop(sw, lstrTableName);
        sb = new System.Text.StringBuilder("\r\n\t/// \r\n\t" + 
             "/// User defined Contructor\r\n\t/// \r\n\tpublic ");
        sbAttr = new System.Text.StringBuilder();
        sb.Append(lstrTableName);
        sb.Append("(");
      }
      else
      {
        this.CreateClassBody(sw, lstrAttributeType, lstrAttributeName);
        sb.AppendFormat("{0} {1}, \r\n\t\t", 
           new object[]{lstrAttributeType, lstrAttributeName});
        sbAttr.AppendFormat("\r\n\t\tthis._{0} = {0};", 
           new object[]{lstrAttributeName});
      }
      lstrOldTableName = lstrTableName;
      this.progressBarMain.Increment(1); 
    }
    MessageBox.Show("Done !!");
  }
}

Once this method is called, it does every thing for you.

i hope it will helps you....

Answer 5

i think the easiest way to generate cs class from table is query on your database , for example in SQL server you can use this query:

declare @tblName sysname = 'SetYourTableName'
declare @ResultText varchar(max) = 'public class ' + @tblName + '
{'

select @ResultText = @ResultText + '
    public ' + ColumnType + NullableSign + ' ' + ColumnName + ' { get; set; }
'
from
(
    select 
        replace(col.name, ' ', '_') ColumnName,
        column_id ColumnId,
        case typ.name 
            when 'bigint' then 'long'
            when 'binary' then 'byte[]'
            when 'bit' then 'bool'
            when 'char' then 'string'
            when 'date' then 'DateTime'
            when 'datetime' then 'DateTime'
            when 'datetime2' then 'DateTime'
            when 'datetimeoffset' then 'DateTimeOffset'
            when 'decimal' then 'decimal'
            when 'float' then 'float'
            when 'image' then 'byte[]'
            when 'int' then 'int'
            when 'money' then 'decimal'
            when 'nchar' then 'string'
            when 'ntext' then 'string'
            when 'numeric' then 'decimal'
            when 'nvarchar' then 'string'
            when 'real' then 'double'
            when 'smalldatetime' then 'DateTime'
            when 'smallint' then 'short'
            when 'smallmoney' then 'decimal'
            when 'text' then 'string'
            when 'time' then 'TimeSpan'
            when 'timestamp' then 'DateTime'
            when 'tinyint' then 'byte'
            when 'uniqueidentifier' then 'Guid'
            when 'varbinary' then 'byte[]'
            when 'varchar' then 'string'
            else 'UNKNOWN_' + typ.name
        end ColumnType,
        case 
            when col.is_nullable = 1 and typ.name in ('bigint', 'bit', 'date', 'datetime', 'datetime2', 'datetimeoffset', 'decimal', 'float', 'int', 'money', 'numeric', 'real', 'smalldatetime', 'smallint', 'smallmoney', 'time', 'tinyint', 'uniqueidentifier') 
            then '?' 
            else '' 
        end NullableSign
    from sys.columns col
        join sys.types typ on
            col.system_type_id = typ.system_type_id AND col.user_type_id = typ.user_type_id
    where object_id = object_id(@tblName)
) t
order by ColumnId

set @ResultText = @ResultText  + '
}'

print @ResultText

then Run this query and copy printed Result text in New Class in Visual Studio

i hope works for you

good luck