Question

我想知道如何通过运行SQL查询来发现我的SQL Server数据库中哪些表彼此相关。

例如，假设我有2个多对多关系和3个用一些随机值初始化的表。

create table A (pk int not null primary key identity, A int);
create table B (pk int not null primary key identity, B int);
create table C (pk int not null primary key identity, C int);

create table AB 
(
    a_pk int not null references A,
    b_pk int not null references B,
    primary key(a_pk, b_pk)
);

create table AC 
(
    a_pk int not null references A,
    c_pk int not null references C,
    primary key(a_pk, c_pk)
);

我想运行一个参数化查询，其输出类似于：

使用参数'A'：

MM_TAB  |  REL_TAB
------------------
  AB    |    B 
  AC    |    C

使用参数'B'：

MM_TAB  |  REL_TAB
------------------
  AB    |    A

使用参数“C”：

MM_TAB  |  REL_TAB
------------------
  AC    |    A

我该怎么做？

Answer 1

检查出来：

我使用SQL Server 2014创建了表和关系：

create database relation

use relation

create table A (pk int not null primary key identity, A int);
create table B (pk int not null primary key identity, B int);
create table C (pk int not null primary key identity, C int);

create table AB 
(
    a_pk int not null  foreign key references A(pk),
    b_pk int not null foreign key references B(pk),
    primary key(a_pk, b_pk)
);

create table AC 
(
    a_pk int not null  foreign key references A(pk),
    c_pk int not null foreign key references C(pk),
    primary key(a_pk, c_pk)
);

然后您可以使用此查询来查找相关表：

    use relation 
go

DECLARE @table_param NVARCHAR(2)='A';

with rel as(
        SELECT 
            K_Table = FK.TABLE_NAME,
            --FK_Column = CU.COLUMN_NAME,
            PK_Table = PK.TABLE_NAME
            --PK_Column = PT.COLUMN_NAME,
            --Constraint_Name = C.CONSTRAINT_NAME
        FROM 
            INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
        INNER JOIN 
            INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
        INNER JOIN 
            INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
        INNER JOIN 
            INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
        wHERE PK.TABLE_NAME = @table_param

)

SELECT 
    K_Table = FK.TABLE_NAME,
    --FK_Column = CU.COLUMN_NAME,
    PK_Table = PK.TABLE_NAME
    --PK_Column = PT.COLUMN_NAME,
    --Constraint_Name = C.CONSTRAINT_NAME
FROM 
    INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS C
INNER JOIN 
    INFORMATION_SCHEMA.TABLE_CONSTRAINTS FK ON C.CONSTRAINT_NAME = FK.CONSTRAINT_NAME
INNER JOIN 
    INFORMATION_SCHEMA.TABLE_CONSTRAINTS PK ON C.UNIQUE_CONSTRAINT_NAME = PK.CONSTRAINT_NAME
INNER JOIN 
    INFORMATION_SCHEMA.KEY_COLUMN_USAGE CU ON C.CONSTRAINT_NAME = CU.CONSTRAINT_NAME
WHERE FK.TABLE_NAME IN(SELECT R.K_Table FROM REL R)

从SQL Server查找表关系

1 个答案: