有一个table1有table2的外键(一个table2到多个table1)。如何获取table2字段列表:
"table2.f1"
"table2.f2"
"table2.f3"
只需提供“table1.f3”(具有表2的外键)。如何从系统表中选择它?
列出 FK 表和字段引用的所有内容。
SELECT
detail_index_segments.rdb$field_name AS field_name,
master_relation_constraints.rdb$relation_name AS reference_table,
master_index_segments.rdb$field_name AS fk_field
FROM
rdb$relation_constraints detail_relation_constraints
JOIN rdb$index_segments detail_index_segments ON detail_relation_constraints.rdb$index_name = detail_index_segments.rdb$index_name
JOIN rdb$ref_constraints ON detail_relation_constraints.rdb$constraint_name = rdb$ref_constraints.rdb$constraint_name -- Master indeksas
JOIN rdb$relation_constraints master_relation_constraints ON rdb$ref_constraints.rdb$const_name_uq = master_relation_constraints.rdb$constraint_name
JOIN rdb$index_segments master_index_segments ON master_relation_constraints.rdb$index_name = master_index_segments.rdb$index_name
WHERE
detail_relation_constraints.rdb$constraint_type = 'FOREIGN KEY'
AND detail_relation_constraints.rdb$relation_name = :table_name
获取特定表的外键引用的all外键目标(即主键或唯一键)的查询可以使用下面的查询来查询。我认为这将为您提供足够的信息来获取特定专栏的信息:
select
PK.RDB$RELATION_NAME as PKTABLE_NAME
,ISP.RDB$FIELD_NAME as PKCOLUMN_NAME
,FK.RDB$RELATION_NAME as FKTABLE_NAME
,ISF.RDB$FIELD_NAME as FKCOLUMN_NAME
,(ISP.RDB$FIELD_POSITION + 1) as KEY_SEQ
,RC.RDB$UPDATE_RULE as UPDATE_RULE
,RC.RDB$DELETE_RULE as DELETE_RULE
,PK.RDB$CONSTRAINT_NAME as PK_NAME
,FK.RDB$CONSTRAINT_NAME as FK_NAME
from
RDB$RELATION_CONSTRAINTS PK
,RDB$RELATION_CONSTRAINTS FK
,RDB$REF_CONSTRAINTS RC
,RDB$INDEX_SEGMENTS ISP
,RDB$INDEX_SEGMENTS ISF
WHERE FK.RDB$RELATION_NAME = ? and
FK.RDB$CONSTRAINT_NAME = RC.RDB$CONSTRAINT_NAME
and PK.RDB$CONSTRAINT_NAME = RC.RDB$CONST_NAME_UQ
and ISP.RDB$INDEX_NAME = PK.RDB$INDEX_NAME
and ISF.RDB$INDEX_NAME = FK.RDB$INDEX_NAME
and ISP.RDB$FIELD_POSITION = ISF.RDB$FIELD_POSITION
order by 1, 5
AbstractDatabaseMetaData