在项目中经常要手动创建和数据库对应的实体类，如果数据库表比较多或者表字段比较多，那会是一个工作量非常大的事情，所以我根据自己的需求写了一个简单的代码生成工具，工具使用Easy4net框架开发。
下面是代码目录结构：
项目开始预备步骤：
1. 创建项目EntityCodeBuilder
2. 引入Easy4net项目源码
3. 创建Entity类库
4. 创建TableName和TableColumn类
5. 在App.config配置文件中配置数据库连接信息
TableName源码：
using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace EntityCodeBuilder.Entity
{ public class TableName
{ public string Name { get; set; }
}
}
TableColumn源码：
using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace EntityCodeBuilder.Entity
{ public class TableColumn
{ public string Name { get; set; } public string Type { get; set; } public string IsIdentity { get; set; } public string IsPrimaryKey { get; set; } public string IsNull { get; set; }
}
}
App.config配置文件代码：
<appSettings> <add key="DbType" value="sqlserver"/> <add key="connectionString" value="Data Source=.;Initial Catalog=test;User ID=test;Password=test123;Trusted_Connection=no;Min Pool Size=10;Max Pool Size=100;"/> <!--<add key="DbType" value="mysql"/> <add key="connectionString" value="Data Source=.;port=8001;User ID=test;Password=123456;DataBase=test;Min Pool Size=10;Max Pool Size=100;"/>--> </appSettings>
UI上的代码不细说了，主要是有几个类的代码：
TableHelper中的代码，获取数据库所有表名：
/// <summary>
/// 获取数据库所有表名
/// </summary>
/// <param name="connection"></param>
/// <returns></returns>
public static List<TableName> GetTables()
{
SqlConnection connection = (SqlConnection)DbFactory.CreateDbConnection(AdoHelper.ConnectionString);
List<TableName> tablelist = new List<TableName>(); try
{ if (connection.State == ConnectionState.Closed)
{
connection.Open();
DataTable objTable = connection.GetSchema("Tables"); foreach (DataRow row in objTable.Rows)
{
TableName tb = new TableName();
tb.Name = row[2].ToString();
tablelist.Add(tb);
}
}
} catch(Exception e)
{ throw e;
} finally
{ if (connection != null && connection.State == ConnectionState.Closed)
{
connection.Dispose();
}
} return tablelist;
}
TableHelper中的代码，根据表名获取所有列：
/// <summary>
/// 获取字段
/// </summary>
/// <param name="connection"></param>
/// <param name="TableName"></param>
/// <returns></returns>
public static List<TableColumn> GetColumnField(string TableName)
{
StringBuilder sb = new StringBuilder();
sb.Append(" SELECT a.name,");
sb.Append(" b.name as type,");
sb.Append(" CASE COLUMNPROPERTY(a.id,a.name,‘IsIdentity‘) WHEN 1 THEN ‘√‘ ELSE ‘‘ END as IsIdentity, ");
sb.Append(" CASE WHEN EXISTS ( SELECT * FROM sysobjects WHERE xtype=‘PK‘ AND name IN ( SELECT name FROM sysindexes WHERE id=a.id AND indid IN ( SELECT indid FROM sysindexkeys ");
sb.Append(" WHERE id=a.id AND colid IN ( SELECT colid FROM syscolumns WHERE id=a.id AND name=a.name ) ) ) ) THEN ‘√‘ ELSE ‘‘ END as IsPrimaryKey,");
sb.Append(" CASE a.isnullable WHEN 1 THEN ‘√‘ ELSE ‘‘ END as IsNull ");
sb.Append(" FROM syscolumns a ");
sb.Append(" LEFT JOIN systypes b ON a.xtype=b.xusertype ");
sb.Append(" INNER JOIN sysobjects c ON a.id=c.id AND c.xtype=‘U‘ AND c.name<>‘dtproperties‘ ");
sb.Append(" LEFT JOIN syscomments d ON a.cdefault=d.id ");
sb.Append(" WHERE c.name = ‘").Append(TableName).Append("‘ ");
sb.Append(" ORDER BY c.name, a.colorder"); //使用Easy4net框架查询数据
List<TableColumn> list = db.FindBySql<TableColumn>(sb.ToString()); return list;
}
知道表名，字段名称，字段类型后，要生成实体类，需要根据数据库中的数据类型转换为C#中的类型：
using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace WindowsDemo
{ public class TypeHelper
{ public static string GetType(string type)
{ string newType = "String"; switch (type)
{ case "varchar": case "varchar2": case "nvarchar": case "char":
newType = "String"; break; case "int": case "integer": case "bit": case "smallint":
newType = "int"; break; case "long": case "bitint":
newType = "long"; break; case "date": case "datetime": case "datetime2": case "datetimeoffset":
newType = "DateTime"; break; case "decimal": case "number": case "money": case "numeric":
newType = "Decimal"; break; case "double":
newType = "double"; break; case "float":
newType = "float"; break;
} return newType;
}
}
}
下面就是生成代码的具体步骤了：
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.IO;using EntityCodeBuilder.Entity;namespace WindowsDemo
{ public class CreateFileHelper
{ /// <summary>
/// 创建类文件目录和文件 /// </summary>
/// <param name="tables">所有表</param>
/// <param name="fileDir">文件目录</param>
public static void Create(List<TableName> tables, string fileDir)
{
CreateDirectory(fileDir); foreach (TableName table in tables)
{ //实体类名称
string entityName = GenVarName(table.Name); //实体类文件名
string filePath = fileDir + entityName + ".cs"; //文件是否存在
bool exists = File.Exists(filePath); //创建文件
FileStream fs = new FileStream(filePath, exists ? FileMode.Open : FileMode.Create, FileAccess.Write);
StreamWriter sw = new StreamWriter(fs); //生成代码
string code = CreateFileHelper.BuilderCode(table.Name); //写入代码到文件 sw.WriteLine(code);
sw.Close();
fs.Close();
}
} /// <summary>
/// 创建文件目录 /// </summary>
/// <param name="targetDir"></param>
private static void CreateDirectory(string targetDir)
{
DirectoryInfo dir = new DirectoryInfo(targetDir); if (!dir.Exists)
dir.Create();
} /// <summary>
/// 根据表名，生成代码 /// </summary>
/// <param name="tableName">表名</param>
/// <returns></returns>
public static string BuilderCode(string tableName)
{ string entityName = GenVarName(tableName);
StringBuilder sb = new StringBuilder();
sb.Append("using System;").Append("\n");
sb.Append("using System.Collections.Generic; ").Append("\n");
sb.Append("using System.Linq; ").Append("\n");
sb.Append("using System.Text; ").Append("\n");
sb.Append("using System.Text; ").Append("\n");
sb.Append("namespace Easy4net.Entity ").Append("\n");
sb.Append("{ ").Append("\n");
sb.Append("\t [Table(Name = \"").Append(tableName).Append("\")] ").Append("\n");
sb.Append("\t public class ").Append(entityName).Append("\n");
sb.Append("\t { ").Append("\n");
List<TableColumn> columns = TableHelper.GetColumnField(tableName); foreach (TableColumn column in columns)
{ string type = TypeHelper.GetType(column.Type); if (column.IsPrimaryKey == "√")
{ //[Id(Name = "UserID", Strategy = GenerationType.INDENTITY)]
string strategy = "GUID"; if (column.IsIdentity == "√")
{
strategy = "INDENTITY";
}
sb.Append("\t\t").Append("[Id(Name = \"").Append(column.Name).Append("\", Strategy = GenerationType.").Append(strategy).Append(")]").Append("\n");
} else
{
sb.Append("\t\t").Append("[Column(Name = \"").Append(column.Name).Append("\")]").Append("\n");
} string fieldName = GenVarName(column.Name);
sb.Append("\t\t").Append("public ").Append(type).Append(" ").Append(fieldName).Append("{ get; set; } \n\n");
}
sb.Append("\t } ").Append("\n");
sb.Append("} ").Append("\n"); return sb.ToString();
} /// <summary>
/// 将数据库中变量名改为驼峰命名 /// 如 user_name 改为 UserName /// </summary>
/// <param name="name">变量名</param>
/// <returns></returns>
public static string GenVarName(string name)
{ string first = name.Substring(0, 1);
name = name.Substring(1, name.Length - 1);
name = first.ToUpper() + name; int index = name.IndexOf("_"); while (index != -1)
{ if (name.Length >= index + 2)
{
first = name.Substring(index + 1, 1); string start = name.Substring(0, index); string end = name.Substring(index + 2, name.Length - index - 2);
name = start + first.ToUpper() + end;
index = name.IndexOf("_");
}
}
name = name.Replace("_", ""); return name;
}
}
}
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使用Easy4net编写代码生成器,布布扣,bubuko.com
原文地址：http://nibao.blog.51cto.com/4681998/1437860
