得到数据库中的表的结构和字段名称

一.Sql 2000得到表字段详细信息。

SELECT 
colorder=a.colorder,--列号
ColumnName=a.name,  --列名称
TypeName=b.name,    --列类型
Length=(case when b.name='nvarchar' then a.length/2 else a.length end), --列长度
Preci=COLUMNPROPERTY(a.id,a.name,'PRECISION'),   --列精度
Scale=isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0), --刻度
IsIdentity=case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end, --是否自动增长
isPK=case when exists(SELECT 1 FROM sysobjects where xtype='PK' and name in (
SELECT name FROM sysindexes WHERE indid in( 
SELECT indid FROM sysindexkeys WHERE id = a.id AND colid=a.colid 
))) then '√' else '' end,                                                            --是否是主键
cisNull=case when a.isnullable=1 then '√'else '' end, --是否允许为空
defaultVal=isnull(e.text,''), --默认值
deText=isnull(g.[value],'')   --注释文字
FROM syscolumns a 
left join systypes b on a.xusertype=b.xusertype 
inner join sysobjects d on a.id=d.id  and (d.xtype='U' or d.xtype='V') and  d.name<>'dtproperties' 
left join syscomments e on a.cdefault=e.id 
left join sysproperties g on a.id=g.id and a.colid=g.smallid 
where d.name='OrderLog'   --这里是表的名称
order by a.id,a.colorder

二.Sql2005得到表字段详细信息。

SELECT 
colorder=C.column_id,
ColumnName=C.name,
TypeName=T.name, 
Length=C.max_length, 
Preci=C.precision, 
Scale=C.scale, 
IsIdentity=CASE WHEN C.is_identity=1 THEN N'\u221a'ELSE N'' END,
isPK=ISNULL(IDX.PrimaryKey,N''),
Computed=CASE WHEN C.is_computed=1 THEN N'\u221a'ELSE N'' END, 
IndexName=ISNULL(IDX.IndexName,N''), 
IndexSort=ISNULL(IDX.Sort,N''), 
Create_Date=O.Create_Date, 
Modify_Date=O.Modify_date, 
cisNull=CASE WHEN C.is_nullable=1 THEN N'\u221a'ELSE N'' END, 
defaultVal=ISNULL(D.definition,N''), 
deText=ISNULL(PFD.[value],N'') 
FROM sys.columns C 
INNER JOIN sys.objects O 
ON C.[object_id]=O.[object_id] 
AND O.type='U' 
AND O.is_ms_shipped=0 
INNER JOIN sys.types T 
ON C.user_type_id=T.user_type_id 
LEFT JOIN sys.default_constraints D 
ON C.[object_id]=D.parent_object_id 
AND C.column_id=D.parent_column_id 
AND C.default_object_id=D.[object_id] 
LEFT JOIN sys.extended_properties PFD 
ON PFD.class=1  
AND C.[object_id]=PFD.major_id  
AND C.column_id=PFD.minor_id 
LEFT JOIN sys.extended_properties PTB 
ON PTB.class=1 
AND PTB.minor_id=0  
AND C.[object_id]=PTB.major_id 
LEFT JOIN 
( 
SELECT  
IDXC.[object_id], 
IDXC.column_id, 
Sort=CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,'IsDescending') 
WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END, 
PrimaryKey=CASE WHEN IDX.is_primary_key=1 THEN N'\u221a'ELSE N'' END, 
IndexName=IDX.Name 
FROM sys.indexes IDX 
INNER JOIN sys.index_columns IDXC 
ON IDX.[object_id]=IDXC.[object_id] 
AND IDX.index_id=IDXC.index_id 
LEFT JOIN sys.key_constraints KC 
ON IDX.[object_id]=KC.[parent_object_id] 
AND IDX.index_id=KC.unique_index_id 
INNER JOIN  
( 
SELECT [object_id], Column_id, index_id=MIN(index_id) 
FROM sys.index_columns 
GROUP BY [object_id], Column_id 
) IDXCUQ 
ON IDXC.[object_id]=IDXCUQ.[object_id] 
AND IDXC.Column_id=IDXCUQ.Column_id 
AND IDXC.index_id=IDXCUQ.index_id 
) IDX 
ON C.[object_id]=IDX.[object_id] 
AND C.column_id=IDX.column_id  
WHERE O.name=N'" + TableName + "'   --这里是表的名称
ORDER BY O.name,C.column_id

三.Oracle得到表字段详细信息。

select 
COLUMN_ID as colorder,  
COLUMN_NAME as ColumnName,
DATA_TYPE as TypeName,
DATA_LENGTH as Length,
DATA_PRECISION as Preci,
DATA_SCALE as Scale,
'' as IsIdentity,
'' as isPK,
"NULLABLE as cisNull ,
DATA_DEFAULT as defaultVal, 
'' as deText 
from USER_TAB_COLUMNS 
where TABLE_NAME='" + TableName + "'   //这里是表名称
order by COLUMN_ID

四.其他的数据库的表字段结构的详细。

public DataTable GetOleDbSchemaTable(Guid schema, object[] restrictions)
  {
   DataTable table1;
   IntPtr ptr1;
   OleDbConnection.ExecutePermission.Demand();
   Bid.ScopeEnter(out ptr1, "<oledb.OleDbConnection.GetOleDbSchemaTable|API> %d#, schema=%p{GUID}, restrictions\n", this.ObjectID, schema);
   try
   {
    this.CheckStateOpen("GetOleDbSchemaTable");
    OleDbConnectionInternal internal1 = this.GetOpenConnection();
    if (OleDbSchemaGuid.DbInfoLiterals == schema)
    {
     if ((restrictions != null) && (restrictions.Length != 0))
     {
      throw ODB.InvalidRestrictionsDbInfoLiteral("restrictions");
     }
     return internal1.BuildInfoLiterals();
    }
    if (OleDbSchemaGuid.SchemaGuids == schema)
    {
     if ((restrictions != null) && (restrictions.Length != 0))
     {
      throw ODB.InvalidRestrictionsSchemaGuids("restrictions");
     }
     return internal1.BuildSchemaGuids();
    }
    if (OleDbSchemaGuid.DbInfoKeywords == schema)
    {
     if ((restrictions != null) && (restrictions.Length != 0))
     {
      throw ODB.InvalidRestrictionsDbInfoKeywords("restrictions");
     }
     return internal1.BuildInfoKeywords();
    }
    if (!internal1.SupportSchemaRowset(schema))
    {
     IDBSchemaRowsetWrapper wrapper1 = internal1.IDBSchemaRowset();
     try
     {
      if (wrapper1.Value == null)
      {
       throw ODB.SchemaRowsetsNotSupported(this.Provider);
      }
     }
     finally
     {
      wrapper1.Dispose();
     }
     throw ODB.NotSupportedSchemaTable(schema, this);
    }
    return internal1.GetSchemaRowset(schema, restrictions);
   }
   finally
   {
    Bid.ScopeLeave(ref ptr1);
   }
   return table1;
  }
  private DataTable Tab2Colum(DataTable sTable)
  {
   DataTable table1 = new DataTable();
   table1.Columns.Add("colorder");
   table1.Columns.Add("ColumnName");
   table1.Columns.Add("TypeName");
   table1.Columns.Add("Length");
   table1.Columns.Add("Preci");
   table1.Columns.Add("Scale");
   table1.Columns.Add("IsIdentity");
   table1.Columns.Add("isPK");
   table1.Columns.Add("cisNull");
   table1.Columns.Add("defaultVal");
   table1.Columns.Add("deText");
   int num1 = 0;
   foreach (DataRow row1 in sTable.Select("", "ORDINAL_POSITION asc"))
   {
    DataRow row2 = table1.NewRow();
    row2["colorder"] = row1[6].ToString();
    row2["ColumnName"] = row1[3].ToString();
    string text1 = row1[11].ToString();
    switch (row1[11].ToString())
    {
     case "3":
      text1 = "int";
      goto Label_01CE;

     case "5":
      text1 = "float";
      goto Label_01CE;

     case "6":
      text1 = "money";
      goto Label_01CE;

     case "7":
      text1 = "datetime";
      goto Label_01CE;

     case "11":
      text1 = "bool";
      break;

     case "130":
      text1 = "varchar";
      break;
    }
   Label_01CE:
    row2["TypeName"] = text1;
    row2["Length"] = row1[13].ToString();
    row2["Preci"] = row1[15].ToString();
    row2["Scale"] = row1[0x10].ToString();
    row2["IsIdentity"] = "";
    row2["isPK"] = "";
    if (row1[10].ToString().ToLower() == "true")
    {
     row2["cisNull"] = "";
    }
    else
    {
     row2["cisNull"] = "\u221a";
    }
    row2["defaultVal"] = row1[8].ToString();
    row2["deText"] = "";
    table1.Rows.Add(row2);
    num1++;
   }
   return table1;
  }