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Home Database Mysql Tutorial Oracle數(shù)據(jù)庫(kù)查詢表的基本信息

Oracle數(shù)據(jù)庫(kù)查詢表的基本信息

Jun 07, 2016 pm 04:55 PM
o oracle database

因?yàn)镺racle項(xiàng)目某些模塊的數(shù)據(jù)結(jié)構(gòu)設(shè)計(jì)沒(méi)有嚴(yán)格按照某規(guī)范設(shè)計(jì),所以只能從數(shù)據(jù)庫(kù)中查詢數(shù)據(jù)結(jié)構(gòu),需要查詢的信息如下:字段

??? 因?yàn)镺racle項(xiàng)目某些模塊的數(shù)據(jù)結(jié)構(gòu)設(shè)計(jì)沒(méi)有嚴(yán)格按照某規(guī)范設(shè)計(jì),所以只能從數(shù)據(jù)庫(kù)中查詢數(shù)據(jù)結(jié)構(gòu),需要查詢的信息如下:字段名稱、數(shù)據(jù)類型、是否為空、默認(rèn)值、主鍵、外鍵等等。

??? 在網(wǎng)上搜索了查詢上述信息的方法,總結(jié)如下:

??? 一,查詢表基本信息

??? select

??? utc.column_name,utc.data_type,utc.data_length,utc.data_precision, utc.data_Scale,utc.nullable,utc.data_default,ucc.comments

??? from

??? user_tab_columns utc,user_col_comments ucc

??? where

??? utc.table_name = ucc.table_name and utc.column_name = ucc.column_name and utc.table_name = 'ONLINEXLS'

??? order by

??? column_id

??? 注意:order by column_id的意義是使得結(jié)果按照設(shè)計(jì)數(shù)據(jù)結(jié)構(gòu)時(shí)的順序顯示。

??? 二,查詢表主鍵

??? select

??? col.column_name

??? from

??? user_constraints con,user_cons_columns col

??? where

??? con.constraint_name=col.constraint_name and con.constraint_type='P' and col.table_name='ONLINEXLS'三,查詢表外鍵

??? select

??? distinct(ucc.column_name) column_name,rela.table_name,rela.column_name column_name1

??? from

??? user_constraints uc,user_cons_columns ucc, (select t2.table_name,t2.column_name,t1.r_constraint_name from user_constraints t1,user_cons_columns t2 where t1.r_constraint_name=t2.constraint_name and t1.table_name='ONLINEXLS') rela

??? where

??? uc.constraint_name=ucc.constraint_name and uc.r_constraint_name=rela.r_constraint_name and uc.table_name='ONLINEXLS'

??? 1、查找表的所有索引(包括索引名,類型,構(gòu)成列):

??? select t.*,i.index_type from user_ind_columns t,user_indexes i where t.index_name = i.index_name and t.table_name = i.table_name and t.table_name = 要查詢的表

??? 2、查找表的主鍵(包括名稱,構(gòu)成列)表名大寫 :

??? select cu.* from user_cons_columns cu, user_constraints au where cu.constraint_name = au.constraint_name and au.constraint_type = 'P' and au.table_name = '要查詢的表' ;

??? 僅查詢表主鍵

??? select column_name from user_cons_columns wherE CONSTRAINT_NAME in (select CONSTRAINT_NAME from user_constraints where table_name =upper('表名') and CONSTRAINT_TYPE='P');

??? 3、查找表的唯一性約束(包括名稱,構(gòu)成列):

??? select column_name from user_cons_columns cu, user_constraints au where cu.constraint_name = au.constraint_name and au.constraint_type = 'U' and au.table_name = 要查詢的表

??? 4、查找表的外鍵(包括名稱,,引用表的表名和對(duì)應(yīng)的鍵名,下面是分成多步查詢):

??? select * from user_constraints c where c.constraint_type = 'R' and c.table_name = 要查詢的表

??? 查詢外鍵約束的列名:

??? select * from user_cons_columns cl where cl.constraint_name = 外鍵名稱

??? 查詢引用表的鍵的列名:

??? select * from user_cons_columns cl where cl.constraint_name = 外鍵引用表的鍵名

??? 5、查詢表的所有列及其屬性

??? select t.*,c.COMMENTS from user_tab_columns t,user_col_comments c where t.table_name = c.table_name and t.column_name = c.column_name and t.table_name = 要查詢的

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