获取数据库表及表结构

原文：http://www.cnblogs.com/StrangeCity/p/4352753.html

此例子，博主将使用SQL Server 2008 R2 做数据库，使用Winform做工具的UI展示。

1、执行以下sql，即可从SQL server 数据库得到相关表和字段的基础信息（SQL Server 2008 R2 亲测有效）

1 SELECT *
2 FROM master..sysdatabases

 1 select  
 2     [表名]=c.Name, 
 3     [表说明]=isnull(f.[value],''),  
 4     [列序号]=a.Column_id,  
 5     [列名]=a.Name,  
 6     [列说明]=isnull(e.[value],''),  
 7     [数据库类型]=b.Name,    
 8     [类型]= case when b.Name = 'image' then 'byte[]'
 9                  when b.Name in('image','uniqueidentifier','ntext','varchar','ntext','nchar','nvarchar','text','char') then 'string'
10                  when b.Name in('tinyint','smallint','int','bigint') then 'int'
11                  when b.Name in('datetime','smalldatetime') then 'DateTime'
12                  when b.Name in('float','decimal','numeric','money','real','smallmoney') then 'decimal'
13                  when b.Name ='bit' then 'bool' else b.name end ,
14     [标识]= case when is_identity=1 then '是' else '' end,  
15     [主键]= case when exists(select 1 from sys.objects x join sys.indexes y on x.Type=N'PK' and x.Name=y.Name  
16                         join sysindexkeys z on z.ID=a.Object_id and z.indid=y.index_id and z.Colid=a.Column_id)  
17                     then '是' else '' end,      
18     [字节数]=case when a.[max_length]=-1 and b.Name!='xml' then 'max/2G'  
19                   when b.Name='xml' then '2^31-1字节/2G' 
20                   else rtrim(a.[max_length]) end,  
21     [长度]=case when ColumnProperty(a.object_id,a.Name,'Precision')=-1 then '2^31-1' 
22                 else rtrim(ColumnProperty(a.object_id,a.Name,'Precision')) end,  
23     [小数位]=isnull(ColumnProperty(a.object_id,a.Name,'Scale'),0),  
24     [是否为空]=case when a.is_nullable=1 then '是' else '' end,      
25     [默认值]=isnull(d.text,'')      
26 from  
27     sys.columns a  
28 left join 
29     sys.types b on a.user_type_id=b.user_type_id  
30 inner join 
31     sys.objects c on a.object_id=c.object_id and c.Type='U' 
32 left join 
33     syscomments d on a.default_object_id=d.ID  
34 left join 
35     sys.extended_properties e on e.major_id=c.object_id and e.minor_id=a.Column_id and e.class=1   
36 left join 
37     sys.extended_properties f on f.major_id=c.object_id and f.minor_id=0 and f.class=1 
38 
39 获取数据库所有表字段信息

2、构建自定义模板，然后替换模板中的标识符

说到自定义模板，无非就是一堆字符串，那这一堆字符串究竟是用XML存储还是TXT文本存储还是其他方式呢？好吧，咱不纠结到底采用哪种存储介质了。基于本文的“30分钟”，博主决定短平快，直接硬编码写死吧！用字符串对象存储起来。 

 1 string modelTmp = @"
 2 using System;
 3 
 4 namespace #ModelNamespace#
 5 {
 6     /// <summary>
 7     /// #ModelClassDescription#
 8     /// Create By Tool #CreateDateTime#
 9     /// </summary>
10     public class #ModelClassName#
11     {
12 #PropertyInfo#
13     }
14 }";
15 
16 实体类模板

1 string modelPropertyTmp = @"
2          /// <summary>
3          /// #PropertyDescription#
4          /// </summary>
5          public  #PropertyType# #PropertyName# { get; set; }";

 1 propertyInfo += modelPropertyTmp.Replace(" #PropertyDescription#", propertyDescription)
 2                                                         .Replace(" #PropertyType#", propertyType)
 3                                                         .Replace("#PropertyName#", propertyName);
 4 
 5 
 6 modelTmp = modelTmp.Replace("#ModelClassDescription#", this.treeView1.SelectedNode.Tag.ToString())
 7                                        .Replace("#CreateDateTime#", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"))
 8                                        .Replace("#ModelNamespace#", modelNamespace)
 9                                        .Replace("#ModelClassName#", modelClassName)
10                                        .Replace("#PropertyInfo#", propertyInfo);
11 
12 标识符替换

3、采用文本控件将生成的代码打印出来

由于本文旨在让各位读者了解代码生成的原理，故博主花了10多分钟写了一个简单的代码生成器，代码自然有些粗糙，请各位见谅！

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Data;
  4 using System.Data.SqlClient;
  5 using System.Linq;
  6 using System.Windows.Forms;
  7 
  8 namespace WindowsTest
  9 {
 10     public partial class CodeCreate : Form
 11     {
 12         private static string S_conStr = "Data Source=127.0.0.1;Initial Catalog=master;Integrated Security=False;user=sa;password=******;";
 13 
 14         public CodeCreate()
 15         {
 16             InitializeComponent();
 17         }
 18 
 19         public static DataTable ExcuteQuery(string connectionString, string cmdText, List<SqlParameter> pars = null)
 20         {
 21             using (SqlConnection conn = new SqlConnection(connectionString))
 22             {
 23                 using (SqlCommand cmd = new SqlCommand(cmdText, conn))
 24                 {
 25                     if (pars != null && pars.Count > 0) cmd.Parameters.AddRange(pars.ToArray());
 26                     using (SqlDataAdapter adp = new SqlDataAdapter(cmd))
 27                     {
 28                         DataTable dt = new DataTable();
 29                         adp.Fill(dt);
 30                         return dt;
 31                     }
 32                 }
 33             }
 34         }
 35 
 36         private void CodeCreate_Load(object sender, EventArgs e)
 37         {
 38             #region 获取所有数据库的信息
 39             string sql = @" SELECT *
 40                             FROM master..sysdatabases
 41                             where dbid>6
 42                             ORDER BY dbid";
 43             #endregion
 44 
 45             DataTable dt = ExcuteQuery(S_conStr, sql);
 46             this.treeView1.Nodes.Add("192.168.30.69");
 47             foreach (DataRow dr in dt.Rows)
 48             {
 49                 this.treeView1.Nodes[0].Nodes.Add(dr["name"].ToString());
 50             }
 51 
 52             this.treeView1.ExpandAll();
 53         }
 54 
 55         private void treeView1_AfterSelect(object sender, TreeViewEventArgs e)
 56         {
 57             this.tabControl1.SelectedIndex = 0;
 58 
 59             if (e.Node.Level == 0) return;
 60 
 61             #region 获取数据库所有表字段信息的sql
 62             string sql = @"
 63 select  
 64     [表名]=c.Name, 
 65     [表说明]=isnull(f.[value],''),  
 66     [列序号]=a.Column_id,  
 67     [列名]=a.Name,  
 68     [列说明]=isnull(e.[value],''),  
 69     [数据库类型]=b.Name,    
 70     [类型]= case when b.Name = 'image' then 'byte[]'
 71                  when b.Name in('image','uniqueidentifier','ntext','varchar','ntext','nchar','nvarchar','text','char') then 'string'
 72                  when b.Name in('tinyint','smallint','int','bigint') then 'int'
 73                  when b.Name in('datetime','smalldatetime') then 'DateTime'
 74                  when b.Name in('float','decimal','numeric','money','real','smallmoney') then 'decimal'
 75                  when b.Name ='bit' then 'bool' else b.name end ,
 76     [标识]= case when is_identity=1 then '是' else '' end,  
 77     [主键]= case when exists(select 1 from sys.objects x join sys.indexes y on x.Type=N'PK' and x.Name=y.Name  
 78                         join sysindexkeys z on z.ID=a.Object_id and z.indid=y.index_id and z.Colid=a.Column_id)  
 79                     then '是' else '' end,      
 80     [字节数]=case when a.[max_length]=-1 and b.Name!='xml' then 'max/2G'  
 81                   when b.Name='xml' then '2^31-1字节/2G' 
 82                   else rtrim(a.[max_length]) end,  
 83     [长度]=case when ColumnProperty(a.object_id,a.Name,'Precision')=-1 then '2^31-1' 
 84                 else rtrim(ColumnProperty(a.object_id,a.Name,'Precision')) end,  
 85     [小数位]=isnull(ColumnProperty(a.object_id,a.Name,'Scale'),0),  
 86     [是否为空]=case when a.is_nullable=1 then '是' else '' end,      
 87     [默认值]=isnull(d.text,'')      
 88 from  
 89     sys.columns a  
 90 left join 
 91     sys.types b on a.user_type_id=b.user_type_id  
 92 inner join 
 93     sys.objects c on a.object_id=c.object_id and c.Type='U' 
 94 left join 
 95     syscomments d on a.default_object_id=d.ID  
 96 left join 
 97     sys.extended_properties e on e.major_id=c.object_id and e.minor_id=a.Column_id and e.class=1   
 98 left join 
 99     sys.extended_properties f on f.major_id=c.object_id and f.minor_id=0 and f.class=1 ";
100             #endregion
101 
102             if (e.Node.Level == 1)
103             {
104                 DataTable dt = ExcuteQuery(S_conStr.Replace("master", e.Node.Text), sql);
105                 this.dataGridView1.DataSource = dt;
106 
107                 if (dt.Rows.Count > 0)
108                 {
109                     e.Node.Nodes.Clear();
110                     DataRow[] aryDr = new DataRow[dt.Rows.Count];
111                     dt.Rows.CopyTo(aryDr, 0);
112                     List<string> listTableName = aryDr.Select(a => a["表名"].ToString()).Distinct().ToList();
113                     listTableName.ForEach(a =>
114                     {
115                         e.Node.Nodes.Add(a, a);
116                     });
117                     e.Node.ExpandAll();
118                 }
119             }
120 
121             if (e.Node.Level == 2)
122             {
123                 sql += "where c.Name=@TableName ";
124                 List<SqlParameter> listSqlParameter = new List<SqlParameter>()
125                 {
126                     new SqlParameter("@TableName",e.Node.Text),
127                 };
128                 DataTable dt = ExcuteQuery(S_conStr.Replace("master", e.Node.Parent.Text), sql, listSqlParameter);
129                 if (dt.Columns.Count > 0)
130                 {
131                     if (dt.Rows.Count > 0)
132                     {
133                         e.Node.Tag = dt.Rows[0]["表说明"].ToString();
134                     }
135                     dt.Columns.Remove("表名");
136                     dt.Columns.Remove("表说明");
137                 }
138                 this.dataGridView1.DataSource = dt;
139             }
140         }
141 
142         private void tabControl1_SelectedIndexChanged(object sender, EventArgs e)
143         {
144             if (this.tabControl1.SelectedTab.Text == "Model")
145             {
146                 if (this.treeView1.SelectedNode.Level == 2 && this.dataGridView1.Rows.Count > 0)
147                 {
148                     string modelTmp = @"
149 using System;
150 
151 namespace #ModelNamespace#
152 {
153     /// <summary>
154     /// #ModelClassDescription#
155     /// Create By Tool #CreateDateTime#
156     /// </summary>
157     public class #ModelClassName#
158     {
159 #PropertyInfo#
160     }
161 }";
162 
163                     string modelNamespace = "Model";
164                     string modelClassName = this.treeView1.SelectedNode.Text;
165 
166                     string propertyInfo = string.Empty;
167                     foreach (DataGridViewRow dgvr in this.dataGridView1.Rows)
168                     {
169                         string modelPropertyTmp = @"
170         /// <summary>
171         /// #PropertyDescription#
172         /// </summary>
173         public  #PropertyType# #PropertyName# { get; set; }";
174 
175                         string propertyDescription = dgvr.Cells["列说明"].Value.ToString().Trim();
176                         string propertyName = dgvr.Cells["列名"].Value.ToString().Trim();
177                         string propertyType = dgvr.Cells["类型"].Value.ToString().Trim();
178 
179                         propertyInfo += modelPropertyTmp.Replace(" #PropertyDescription#", propertyDescription)
180                                                         .Replace(" #PropertyType#", propertyType)
181                                                         .Replace("#PropertyName#", propertyName);
182                         propertyInfo += Environment.NewLine;
183                     }
184 
185                     modelTmp = modelTmp.Replace("#ModelClassDescription#", this.treeView1.SelectedNode.Tag.ToString())
186                                        .Replace("#CreateDateTime#", DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"))
187                                        .Replace("#ModelNamespace#", modelNamespace)
188                                        .Replace("#ModelClassName#", modelClassName)
189                                        .Replace("#PropertyInfo#", propertyInfo);
190 
191                     this.richTextBox1.Text = modelTmp;
192                     Clipboard.SetDataObject(this.richTextBox1.Text);
193                 }
194             }
195         }
196     }
197 }
198 
199 主要代码