Oracle 查看表结构

一直以来对，PLSQL里的查看表结构念念，想通过SQL实现。但是默认值是Long类型，取不出字符。终于今天想到了一个方法。这个语句只能查询当前用户的表结构，可用于写文档时，直接复制到文档里。

CREATE OR REPLACE fUNCTION GET_Datadefault(in_table_name varchar,
                                           in_column     varchar2)
  RETURN varchar AS
  text_c1 varchar2(32767);
  sql_cur varchar2(2000);
begin
  sql_cur := \’select  Data_default \’  ||
             \’  from user_tab_columns \’ ||
             \’ where column_name =\’ || chr(39) || in_column || chr(39) ||
             \’  and  Table_Name=\’ || chr(39) || in_table_name || chr(39);
  dbms_output.put_line(sql_cur);
  execute immediate sql_cur
    into text_c1;

  text_c1 := substr(text_c1, 1, 4000);
  RETURN TEXT_C1;
END;

–查询表结构
select A.column_name 名称,
       Case
         When a.Data_Type = \’VARCHAR2\’ Then
          \’VARCHAR2(\’ || a.Data_Length || \’)\’
         When a.Data_Type = \’NUMBER\’ and A.Data_Scale = 0 Then
          \’INTEGER\’
         When a.Data_Type = \’NUMBER\’ and A.data_precision > 0 Then
          \’NUMBER(\’ || a.data_precision || \’,\’ || A.Data_Scale || \’)\’
         Else
          a.Data_Type
       End 类型,
       decode(A.nullable, \’Y\’, \’Y\’, \’\’) 可为空,
       GET_Datadefault(A.Table_Name, a.COLUMN_NAME) 默认,
       B.comments 注释,
       (Select \’Y\’
          From User_Constraints Con, User_Cons_Columns Col
         Where Con.Constraint_Name = Col.Constraint_Name
           And Con.Constraint_Type = \’P\’
           And Col.Column_Name = a.Column_Name
           And Col.Table_Name = a.Table_Name) 主键
  from user_tab_columns A, user_col_comments B
 where a.COLUMN_NAME = b.column_name
   and A.Table_Name = B.Table_Name
   and A.Table_Name = \’FREIGHT_PRICE_RANGE\’–表名
 order by A.COLUMN_ID

转载于:Oracle/3318604