如何確定在HSQLDB中定義了哪些外鍵？

Question

如何判斷在HSQLDB中定義了哪些外鍵？

我從文檔gleened的最好的是：

select * from INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS; 

但是，只給了我以下。

CONSTRAINT_CATALOG CONSTRAINT_SCHEMA CONSTRAINT_NAME UNIQUE_CONSTRAINT_CATALOG UNIQUE_CONSTRAINT_SCHEMA UNIQUE_CONSTRAINT_NAME MATCH_OPTION UPDATE_RULE DELETE_RULE 
------------------ ----------------- --------------- ------------------------- ------------------------ ---------------------- ------------ ----------- ----------- 
PUBLIC    PUBLIC   SYS_FK_10078 PUBLIC     PUBLIC     SYS_PK_10029   NONE   NO ACTION CASCADE  
PUBLIC    PUBLIC   SYS_FK_10079 PUBLIC     PUBLIC     SYS_PK_10029   NONE   NO ACTION NO ACTION 
PUBLIC    PUBLIC   SYS_FK_10080 PUBLIC     PUBLIC     SYS_PK_10071   NONE   NO ACTION CASCADE  
PUBLIC    PUBLIC   SYS_FK_10116 PUBLIC     PUBLIC     SYS_PK_10071   NONE   NO ACTION CASCADE  
PUBLIC    PUBLIC   SYS_FK_10120 PUBLIC     PUBLIC     SYS_PK_10029   NONE   NO ACTION CASCADE  
PUBLIC    PUBLIC   SYS_FK_10124 PUBLIC     PUBLIC     SYS_PK_10029   NONE   NO ACTION NO ACTION 
PUBLIC    PUBLIC   SYS_FK_10128 PUBLIC     PUBLIC     SYS_PK_10071   NONE   NO ACTION CASCADE  
PUBLIC    PUBLIC   SYS_FK_10131 PUBLIC     PUBLIC     SYS_PK_10071   NONE   NO ACTION CASCADE  

我需要知道哪些表和列有外鍵分配，我需要能夠刪除它們。

Answer 1

您可以使用下面的選擇結合REFERENTIAL_CONSTRAINTS查看：

select * from information_schema.constraint_column_usage 
select * from information_schema.constraint_table_usage 

另外，該INFORMATION_SCHEMA.SYSTEM_CROSSREFERENCE觀點是外鍵，它們的表和字段的自包含的視圖。

查看http://hsqldb.org/doc/2.0/guide/databaseobjects-chapt.html#dbc_information_schema的列表。