如何检查vb .net项目中sql server中是否存在数据库和表？ [英] How to check if a database and tables exist in sql server in a vb .net project?

问题描述

有谁能告诉我如何从vb.net项目检查sql server中是否存在数据库和表？我想要做的是检查数据库是否存在（最好是在'If'语句中，除非有人有更好的方法）并且如果它确实存在我会做一件事，如果它不存在我创建数据库与表和列。任何有关此事的帮助将不胜感激。



编辑：



该应用程序已连接到一台服务器。当应用程序在PC上运行时，我希望它检查数据库是否存在，如果存在，那么它会继续并执行它应该执行的操作，但是如果数据库不存在则会先创建数据库，然后继续执行应该怎么做。所以基本上我希望它在第一次在PC上运行时创建数据库然后继续它的业务，然后每次它在PC上运行之后，我希望它看到数据库存在然后继续它的业务。我想要这样的原因是因为这个应用程序将在多台PC上，我只想创建一次数据库和表（第一次在PC上运行），然后当它在不同的PC上运行时，它看到数据库已经存在，然后使用在另一台PC上创建的现有数据库运行应用程序。

解决方案

检查此代码项目文章



检查是否数据库中存在一个表或字段 [ ^ ]



和这篇帖子here

尝试打开与服务器的连接。如果它导致你知道的异常。

 使用 oSqlConnection  As  新 SqlConnection（  ConnectionString）
 oSqlConnection.Open（）
 结束 使用 
）

检查桌子。

  SELECT  * 
  FROM  INFORMATION_SCHEMA.TABLES T 
  WHERE  T.TABLE_NAME  LIKE  ' ％MY_TABLE％' 

将所有内容放在VB中。

 使用 oSqlConnection 作为 新 SqlConnection（My.Settings.ProductTraxConnectionString）
 oSqlConnection.Open（）
 使用 oQuery  As  新 SqlCommand（
   SELECT COUNT（*）& 
   FROM INFORMATION_SCHEMA.TABLES T& 
   WHERE T.TABLE_NAME LIKE @LookupTable，oSqlConnection）
 oQuery。 Parameters.AddWithValue（  @ LookupTable， ％MY_TABLE％）
 
 
  Dim  oResult < span class =code-keyword> as   object  = oQuery.ExecuteScalar（）
  End  使用 
 结束 使用 

如果您正在使用sql server以下查询



select * from sys .Databases其中Name ='urDataBaseName'



获取数据库详细信息



用于检查表格那个DataBase

使用urDataBaseName;

select * f rom TableName



让我知道这是你认为你想的问题。

快乐编码： - ）

Can anyone tell me how I would go about checking if a database and tables exists in sql server from a vb.net project? What I want to do is check if a database exists (preferably in an 'If' statement, unless someone has a better way of doing it) and if it does exist I do one thing and if it doesn't exist I create the database with the tables and columns. Any help on this matter would be greatly appreciated.

Edit:

The application has a connection to a server. When the application runs on a PC I want it to check that a database exists, if one exists then it goes and does what it's supposed to do, but if a database does NOT exist then it creates the database first and then goes on to do what it's supposed to do. So basically I want it to create the database the first time it runs on a PC and then go about it's business, then each time it runs on the PC after that I want it to see that the database exists and then go about it's business. The reason I want it like this is because this application will be on more than one PC, I only want the database and tables created once, (the first time it runs on a PC) and then when it runs on a different PC, it sees that the database already exists and then run the application using the existing database created on the other PC.

解决方案

Check this codeproject article

Check if a table or field exists in a database[^]

and this post here

Try to open the connection to the Server. If it causes an exception you know.

Using oSqlConnection As New SqlConnection("ConnectionString")
        oSqlConnection.Open()
End Using
)

To check for a table.

SELECT *
FROM INFORMATION_SCHEMA.TABLES T
WHERE T.TABLE_NAME LIKE '%MY_TABLE%'

Putting it all together in VB.

Using oSqlConnection As New SqlConnection(My.Settings.ProductTraxConnectionString)
	oSqlConnection.Open()
	Using oQuery As New SqlCommand(
		"SELECT COUNT(*) " &
		"FROM INFORMATION_SCHEMA.TABLES T " & 
		"WHERE T.TABLE_NAME LIKE @LookupTable", oSqlConnection)
		oQuery.Parameters.AddWithValue("@LookupTable", "%MY_TABLE%")


		Dim oResult as object = oQuery.ExecuteScalar()
	End Using
End Using

If you are using sql server the following query

select * from sys.Databases where Name='urDataBaseName'

Gets you the database details

For Checking the Table in that DataBase
Use urDataBaseName;
select * from TableName

Let Me Know this was the Think u was the think you asking.
Happy Coding :-)

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