元查询 ,我的意思是回答问题的查询 关于 具有 数据。

在我得到许多合理的批评之前,我确实意识到元查询的方法并不理想,正如我雄辩地描述的那样 here 例如不过,我相信他们确实有自己的位置(以至于我创建了一个WinForms用户控件,它支持针对sqlserver、Oracle和MySql的参数化元查询,并详细描述了这个QueryPicker的设计和使用 three-part series 发表在Simple Talk.com上。)

我使用元查询的动机:

2. 我经常使用多种数据库类型(SQL Server、Oracle、MySql),并且——实践懒惰的伟大编程理想——我不想每次需要时都要查找或记住一个神秘的SQL配方。我想点击一下。

当然还有其他(更好的?)方法来获取元信息-- . 特别是SQLServer,它提供了SQLServerManagementStudio。Oracle和MySql工具似乎没有提供相同的有用性(我坦率地承认,我是用我倾向于SQL Server的宇宙观提出这一主张的。:-)即使他们这样做了,他们也会有所不同——我想要一个统一的方法 跨数据库类型 .

最后,问题是:

SQL Server、Oracle或MySql元查询的作用 你

汇总矩阵

第一个视图总结了我迄今为止的收藏 数据库类型

Query                            SQL Server    Oracle     MySql

DB Version                           yes        yes        yes
Databases with properties            yes                   yes
Databases with space usage           yes
National Language Support                       yes
Procedures and functions             yes                   yes
Primary keys                         yes                   yes
Primary to foreign keys              yes
Session Information/brief            yes
Session Information/details          yes
Session SET options                  yes
Users and Roles                      yes
Currently running statements         yes
Constraints                          yes
Indexes                              yes
Column info/brief                    yes        yes        yes
Column info/details                  yes        yes        yes
Object level details                 yes
Rows and space used                  yes
Row/column counts                    yes
Non-empty tables                     yes        yes        yes
Show table schema                    yes        yes
Seed/max values                      yes

按数据库类型列出的引用

SQL服务器

System Category
-----------------
    DB Version
    Databases with properties    http://www.mssqltips.com/tip.asp?tip=1033
    Databases with space usage   http://www.sqlservercentral.com/Forums/Topic261080-5-1.aspx
    Procedures and functions
    Primary keys                 http://databases.aspfaq.com/schema-tutorials/schema-how-do-i-show-all-the-primary-keys-in-a-database.html
    Primary to foreign keys      http://www.sqlservercentral.com/scripts/Miscellaneous/61481/
    Session Information/brief    http://www.sqlservercentral.com/blogs/glennberry/archive/2009/12/28/how-to-get-a-count-of-sql-connections-by-ip-address.aspx
    Session Information/details  http://www.mssqltips.com/tip.asp?tip=1817
    Session SET options
    Users and Roles              http://www.sqlservercentral.com/scripts/users/69379/
    Currently running statements http://www.sqlservercentral.com/articles/DMV/64425/
    Constraints
    Indexes                      http://www.sqlservercentral.com/scripts/Index+Management/63932/

Column Category
-----------------
    Column info/brief
    Column info/details

Table Category
-----------------
    Object level details
    Rows and space used          http://www.mssqltips.com/tip.asp?tip=1177
    Row/column counts
    Non-empty tables

DDL Category
-----------------
    Show table schema            http://www.sqlservercentral.com/scripts/Create+DDL+sql+statements/65863/

Data Category
-----------------
    Seed/max values

神谕

System Category
-----------------
    DB Version
    National Language Support

Column Category
-----------------
    Column info/brief
    Column info/details

Table Category
-----------------
    Non-empty tables

DDL Category
-----------------
    Show table schema

System Category
-----------------
    DB Version
    Databases
    Procedures and functions
    Primary keys                 http://databases.aspfaq.com/schema-tutorials/schema-how-do-i-show-all-the-primary-keys-in-a-database.html

Column Category
-----------------
    Column info/brief
    Column info/details

DDL Category
-----------------
    Show table schema