1、查找表的所有索引（包括索引名，类型，构成列）：

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 = 要查询的表

2、查找表的主键（包括名称，构成列）：

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 = 要查询的表

3、查找表的唯一性约束（包括名称，构成列）：

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 = 要查询的表

4、查找表的外键（包括名称，引用表的表名和对应的键名，下面是分成多步查询）：

select * from user_constraints c where c.constraint_type = 'R' and c.table_name = 要查询的表

查询外键约束的列名：

select * from user_cons_columns cl where cl.constraint_name = 外键名称

查询引用表的键的列名：

select * from user_cons_columns cl where cl.constraint_name = 外键引用表的键名

5、查询表的所有列及其属性

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 = 要查询的表

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select o.obj# as objectId, o.name AS tableName, oc.name AS constraintName,
            decode(c.type#, 1, 'C', 2, 'P', 3, 'U', 4, 'R', 5, 'V', 6, 'O', 7,'C', '?')  as constraintType,  col.name AS columnName
from sys.con$ oc, sys.con$ rc,
          sys.obj$ ro,sys.obj$ o, sys.obj$ oi,
          sys.cdef$ c,
          sys.col$ col, sys.ccol$ cc, sys.attrcol$ ac
where oc.con# = c.con#
  and c.obj# = o.obj#
  and c.rcon# = rc.con#(+)
  and c.enabled = oi.obj#(+)
  and c.robj# = ro.obj#(+)
  and c.type# != 8
  and c.type# != 12       /* don't include log groups */
  and c.con# = cc.con#
  and cc.obj# = col.obj#
  and cc.intcol# = col.intcol#
  and cc.obj# = o.obj#
  and col.obj# = ac.obj#(+)
  and col.intcol# = ac.intcol#(+)
  and o.name = 'TABLE_NAME'