利用T4模板，可以很方便的从数据库映射成Model模型，相当于动软等功效。但动软是可以直接生成三层，抽象工厂的，T4没那么牛叉，所以我们一般只用作生成Modle或者Server等指定方法了。
废话少说，切入正题：
下面我将讲解的有两部分，一部分是根据T4将方法属性等生成到一个类里面，另一个是分配生成到不同类里面。
一.根据T4将方法生成到一个类里面
代码如下:
Customers.tt
<#@ assembly name="System.Core.dll" #>
<#@ assembly name="System.Data.dll" #>
<#@ assembly name="System.Data.DataSetExtensions.dll" #>
<#@ assembly name="System.Xml.dll" #>
<#@ import namespace="System" #>
<#@ import namespace="System.Xml" #>
<#@ import namespace="System.Linq" #>
<#@ import namespace="System.Data" #>
<#@ import namespace="System.Data.SqlClient" #>
<#@ import namespace="System.Collections.Generic" #>
<#@ import namespace="System.IO" #>
<#@ include file="$(ProjectDir)DbHelper.ttinclude" #>
using System;
namespace T4ConsoleApplication.Entities
{
public class <#=config.TableName#>
{
<# foreach(DbColumn column in DbHelper.GetDbColumns(config.ConnectionString, config.DbDatabase, config.TableName)){#>
public <#= column.CSharpType#><# if(column.CommonType.IsValueType && column.IsNullable){#>?<#}#> <#=column.ColumnName#> { get; set; }
<#}#>
}
}
<#+
public class config
{
//修改要生成的数据库表
public static readonly string ConnectionString="Data Source=.;Integrated Security=true;";
public static readonly string DbDatabase="Inferno";
public static readonly string TableName="RepositoryModel";
}
#>
DbHelper.ttinclude
<#+
public class DbHelper
{
#region GetDbTables
public static List<DbTable> GetDbTables(string connectionString, string database, string tables = null)
{
if (!string.IsNullOrEmpty(tables))
{
tables = string.Format(" and obj.name in ('{0}')", tables.Replace(",", "','"));
}
#region SQL
string sql = string.Format(@"SELECT
obj.name tablename,
schem.name schemname,
idx.rows,
CAST
(
CASE
WHEN (SELECT COUNT(1) FROM sys.indexes WHERE object_id= obj.OBJECT_ID AND is_primary_key=1) >=1 THEN 1
ELSE 0
END
AS BIT) HasPrimaryKey
from {0}.sys.objects obj
inner join {0}.dbo.sysindexes idx on obj.object_id=idx.id and idx.indid<=1
INNER JOIN {0}.sys.schemas schem ON obj.schema_id=schem.schema_id
where type='U' {1}
order by obj.name", database, tables);
#endregion
DataTable dt = GetDataTable(connectionString, sql);
return dt.Rows.Cast<DataRow>().Select(row => new DbTable
{
TableName = row.Field<string>("tablename"),
SchemaName = row.Field<string>("schemname"),
Rows = row.Field<int>("rows"),
HasPrimaryKey = row.Field<bool>("HasPrimaryKey")
}).ToList();
}
#endregion
#region GetDbColumns
public static List<DbColumn> GetDbColumns(string connectionString, string database, string tableName, string schema = "dbo")
{
#region SQL
string sql = string.Format(@"
WITH indexCTE AS
(
SELECT
ic.column_id,
ic.index_column_id,
ic.object_id
FROM {0}.sys.indexes idx
INNER JOIN {0}.sys.index_columns ic ON idx.index_id = ic.index_id AND idx.object_id = ic.object_id
WHERE idx.object_id =OBJECT_ID(@tableName) AND idx.is_primary_key=1
)
select
colm.column_id ColumnID,
CAST(CASE WHEN indexCTE.column_id IS NULL THEN 0 ELSE 1 END AS BIT) IsPrimaryKey,
colm.name ColumnName,
systype.name ColumnType,
colm.is_identity IsIdentity,
colm.is_nullable IsNullable,
cast(colm.max_length as int) ByteLength,
(
case
when systype.name='nvarchar' and colm.max_length>0 then colm.max_length/2
when systype.name='nchar' and colm.max_length>0 then colm.max_length/2
when systype.name='ntext' and colm.max_length>0 then colm.max_length/2
else colm.max_length
end
) CharLength,
cast(colm.precision as int) Precision,
cast(colm.scale as int) Scale,
prop.value Remark
from {0}.sys.columns colm
inner join {0}.sys.types systype on colm.system_type_id=systype.system_type_id and colm.user_type_id=systype.user_type_id
left join {0}.sys.extended_properties prop on colm.object_id=prop.major_id and colm.column_id=prop.minor_id
LEFT JOIN indexCTE ON colm.column_id=indexCTE.column_id AND colm.object_id=indexCTE.object_id
where colm.object_id=OBJECT_ID(@tableName)
order by colm.column_id", database);
#endregion
SqlParameter param = new SqlParameter("@tableName", SqlDbType.NVarChar, 100) { Value = string.Format("{0}.{1}.{2}", database, schema, tableName) };
DataTable dt = GetDataTable(connectionString, sql, param);
return dt.Rows.Cast<DataRow>().Select(row => new DbColumn()
{
ColumnID = row.Field<int>("ColumnID"),
IsPrimaryKey = row.Field<bool>("IsPrimaryKey"),
ColumnName = row.Field<string>("ColumnName"),
ColumnType = row.Field<string>("ColumnType"),
IsIdentity = row.Field<bool>("IsIdentity"),
IsNullable = row.Field<bool>("IsNullable"),
ByteLength = row.Field<int>("ByteLength"),
CharLength = row.Field<int>("CharLength"),
Scale = row.Field<int>("Scale"),
Remark = row["Remark"].ToString()
}).ToList();
}
#endregion
#region GetDataTable
public static DataTable GetDataTable(string connectionString, string commandText, params SqlParameter[] parms)
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
SqlCommand command = connection.CreateCommand();
command.CommandText = commandText;
command.Parameters.AddRange(parms);
SqlDataAdapter adapter = new SqlDataAdapter(command);
DataTable dt = new DataTable();
adapter.Fill(dt);
return dt;
}
}
#endregion
}
#region DbTable
/// <summary>
/// 表结构
/// </summary>
public sealed class DbTable
{
/// <summary>
/// 表名称
/// </summary>
public string TableName { get; set; }
/// <summary>
/// 表的架构
/// </summary>
public string SchemaName { get; set; }
/// <summary>
/// 表的记录数
/// </summary>
public int Rows { get; set; }
/// <summary>
/// 是否含有主键
/// </summary>
public bool HasPrimaryKey { get; set; }
}
#endregion
#region DbColumn
/// <summary>
/// 表字段结构
/// </summary>
public sealed class DbColumn
{
/// <summary>
/// 字段ID
/// </summary>
public int ColumnID { get; set; }
/// <summary>
/// 是否主键
/// </summary>