如何检查连接字符串是否有效？

我正在编写一个应用程序，其中用户手动提供一个连接字符串，我想知道是否有任何方法可以验证连接字符串-我的意思是检查它是否正确，数据库是否存在。

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最佳答案

You could try to connect? For quick (offline) validation, perhaps use DbConnectionStringBuilder to parse it...

    DbConnectionStringBuilder csb = new DbConnectionStringBuilder();
csb.ConnectionString = "rubb ish"; // throws

But to check whether the db exists, you'll need to try to connect. Simplest if you know the provider, of course:

    using(SqlConnection conn = new SqlConnection(cs)) {
conn.Open(); // throws if invalid
}

If you only know the provider as a string (at runtime), then use DbProviderFactories:

    string provider = "System.Data.SqlClient"; // for example
DbProviderFactory factory = DbProviderFactories.GetFactory(provider);
using(DbConnection conn = factory.CreateConnection()) {
conn.ConnectionString = cs;
conn.Open();
}
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Try this. 

    try
{
using(var connection = new OleDbConnection(connectionString)) {
connection.Open();
return true;
}
}
catch {
return false;
}
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If the goal is validity and not existence, the following will do the trick:

try
{
var conn = new SqlConnection(TxtConnection.Text);
}
catch (Exception)
{
return false;
}
return true;
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For sqlite use this: Suppose you have connection string in textbox txtConnSqlite

     Using conn As New System.Data.SQLite.SQLiteConnection(txtConnSqlite.Text)
Dim FirstIndex As Int32 = txtConnSqlite.Text.IndexOf("Data Source=")
If FirstIndex = -1 Then MsgBox("ConnectionString is incorrect", MsgBoxStyle.Exclamation, "Sqlite") : Exit Sub
Dim SecondIndex As Int32 = txtConnSqlite.Text.IndexOf("Version=")
If SecondIndex = -1 Then MsgBox("ConnectionString is incorrect", MsgBoxStyle.Exclamation, "Sqlite") : Exit Sub
Dim FilePath As String = txtConnSqlite.Text.Substring(FirstIndex + 12, SecondIndex - FirstIndex - 13)
If Not IO.File.Exists(FilePath) Then MsgBox("Database file not found", MsgBoxStyle.Exclamation, "Sqlite") : Exit Sub
Try
conn.Open()
Dim cmd As New System.Data.SQLite.SQLiteCommand("SELECT * FROM sqlite_master WHERE type='table';", conn)
Dim reader As System.Data.SQLite.SQLiteDataReader
cmd.ExecuteReader()
MsgBox("Success", MsgBoxStyle.Information, "Sqlite")
Catch ex As Exception
MsgBox("Connection fail", MsgBoxStyle.Exclamation, "Sqlite")
End Try
End Using

I think you can easilly convert it to c# code


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