如何從表中獲取列類型？

Question

我有這樣的代碼：

select a.id as tableid, 
    a.name as tableName, 
    b.name as columnName, 
    b.status as columnStatus, 
    b.type as columnType 
    from sysobjects a 
    LEFT JOIN syscolumns b 
    ON a.id = b.id 
    WHERE a.name = 'table_name' 

現在，columType顯示號碼。我想獲得名爲columnType的名字，它存在於表'systypes'的'name'列中。我怎麼做？簡單的LEFT JOIN將導致重複的行。

Answer 1

我已經看到了在Sybase 15.0，這是你必須使用代碼：

select o.id [tableid], o.name [tableName], c.name [columnName], c.status [columnStatus], t.name [columnType] from sysobjects o 
inner join syscolumns c on c.id = o.id 
inner join systypes t on t.usertype = c.usertype 
where o.type = 'U' and o.name in ('tablename') 

Answer 2

select o.id [tableid], o.name [tableName], 
c.name [columnName], c.status [columnStatus], 
t.name [columnType] from sysobjects o 
inner join syscolumns c on c.id = o.id 
inner join systypes t on t.type = c.type 
where o.type = 'U' and o.name = 'table_name' 
and t.name not in ('sysname', 'nid', 'uid', 'nvarchar', 'tid', 'nchar') 

我從@aF添加的最後一行。碼。我不知道該如何解釋。我從這裏這樣的回答：http://www.dbforums.com/sybase/913004-getting-column-type.html#post3355703

Answer 3

create function dbo.GetColumnDataTypeName(@TableName TName, @ColumnName TName) 
returns sysname 
as 
begin 
    declare @typeName sysname, 
     @tableId int = object_id(@TableName) 
    select 
    @typeName = type_name(user_type_id) 
    from sys.columns sc 
    where sc.[object_id] = @tableId 
    and sc.Name = @ColumnName 

    return @typeName 
end 
Go 

Answer 4

select so.name as table_name, '' as table_description,sc.name as fileld_name,'' as field_description, 
    st.name as format, 
    sc.length as data_length,sc.prec as decimal_places,'' as primary_key, 
    case when sc.status = 8 then 'Y' 
      else 'N' 
    end as nulls 
    from syscolumns sc 
    INNER JOIN sysobjects so ON sc.id = so.id 
    inner join systypes st on sc.type = st.type 
    WHERE so.name in (/*table list*/) 
    and st.name not in ('sysname', 'nid', 'uid', 'nvarchar', 'tid', 'nchar','longsysname','usr_char') 
    order by so.name 
    go 

Answer 5

有必要加入兩個type和usertype：

SELECT 
o.id  AS tableID, 
o.name AS tableName, 
c.name AS columnName, 
c.status AS columnStatus, 
t.name AS typeName 
FROM  syscolumns AS c NOLOCK 
INNER JOIN systypes AS t NOLOCK 
ON c.type  = t.type 
AND c.usertype = t.usertype 
INNER JOIN sysobjects AS o NOLOCK 
ON c.id = o.id 
INNER JOIN sysusers AS u NOLOCK 
ON o.uid = u.uid 
WHERE o.name = 'table_name' 
AND u.name = 'dbo'