SQL Server 2008:找出表中的主键/外键? [英] SQL Server 2008: Find out primary/foreign key in Table?

问题描述

有谁知道我怎么能看到哪些是主要的&表中的外键?

Does anyone know how I can see which are the primary & foreign keys in a table?

感谢所有回复.我正在寻找一个 SQL 查询来做到这一点.现在我正在编写一个工具，它可以列出数据库的所有表并显示列.我还想显示哪些键是主键.

Thanks for all the responses. I was looking for a SQL Query to do that. Right now I'm playing around with writing a tool which can list me all Tables of a DB and show the columns. I'd like to display also which of the keys are primary keys.

这是我读出表格目录的方式:

This is how I read out the Table Catalog:

const string sqlSelectTable = "SELECT  TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, TABLE_TYPE " +
                                      "FROM INFORMATION_SCHEMA.TABLES " +
                                      "WHERE TABLE_TYPE = 'BASE TABLE' " +
                                      "ORDER BY TABLE_TYPE,TABLE_NAME";

这就是我获取列信息的方式:

And this is how I get the Infos about a Column:

const string sqlSelectTable =
            "SELECT     COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH " +
            "FROM         INFORMATION_SCHEMA.COLUMNS " +
            "WHERE     (TABLE_NAME = @TABLE_NAME) " +
            "ORDER BY ORDINAL_POSITION";

我是否必须创建一个内连接来查看哪些列是主键?

Would I have to create a Inner-Join so see which of the Columns are Primary Key?

干杯

推荐答案

对于每个表的主键，可以使用这个查询:

For the primary key on each table, you can use this query:

SELECT
    kc.name,
    c.NAME
FROM 
    sys.key_constraints kc
INNER JOIN 
    sys.index_columns ic ON kc.parent_object_id = ic.object_id
INNER JOIN 
    sys.columns c ON ic.object_id = c.object_id AND ic.column_id = c.column_id
WHERE
    kc.type = 'PK'

对于外键，我相信这个查询应该为您提供必要的信息:

and for the foreign key, I believe this query should get you the necessary information:

SELECT
    OBJECT_NAME(parent_object_id) 'Parent table',
    c.NAME 'Parent column name',
    OBJECT_NAME(referenced_object_id) 'Referenced table',
    cref.NAME 'Referenced column name'
FROM 
    sys.foreign_key_columns fkc
INNER JOIN 
    sys.columns c 
       ON fkc.parent_column_id = c.column_id 
          AND fkc.parent_object_id = c.object_id
INNER JOIN 
    sys.columns cref 
       ON fkc.referenced_column_id = cref.column_id 
          AND fkc.referenced_object_id = cref.object_id

马克

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