how to create a database connection in csharp

LibraryDatabase
...............\LibraryDB
...............\.........\Backup
...............\.........\......\Backup
...............\.........\......\......\LibraryDB
...............\.........\......\......\.........\BookClass.cs
...............\.........\......\......\.........\CustomerClass.cs
...............\.........\......\......\.........\ErrorLog.cs

...............\.........\......\......\.........\FindDB.cs
...............\.........\......\......\.........\frmAddBooks.cs
...............\.........\......\......\.........\frmAddBooks.Designer.cs
...............\.........\......\......\.........\frmAddBooks.resx
...............\.........\......\......\.........\frmAddCustomers.cs
...............\.........\......\......\.........\frmAddCustomers.Designer.cs
...............\.........\......\......\.........\frmAddCustomers.resx
...............\.........\......\......\.........\frmAddTransactions.cs
...............\.........\......\......\.........\frmAddTransactions.Designer.cs
...............\.........\......\......\.........\frmAddTransactions.resx
...............\.........\......\......\.........\FrmDelete.cs
...............\.........\......\......\.........\FrmDelete.Designer.cs
...............\.........\......\......\.........\FrmDelete.resx
...............\.........\......\......\.........\frmEditBooks.cs
...............\.........\......\......\.........\frmEditBooks.Designer.cs
...............\.........\......\......\.........\frmEditBooks.resx
...............\.........\......\......\.........\frmEditCustomers.cs
...............\.........\......\......\.........\frmEditCustomers.Designer.cs
...............\.........\......\......\.........\frmEditCustomers.resx
...............\.........\......\......\.........\frmReturnTransactions.cs
...............\.........\......\......\.........\frmReturnTransactions.Designer.cs
...............\.........\......\......\.........\frmReturnTransactions.resx
...............\.........\......\......\.........\frmSearchBooks.cs
...............\.........\......\......\.........\frmSearchBooks.Designer.cs
...............\.........\......\......\.........\frmSearchBooks.resx
...............\.........\......\......\.........\frmViewBooks.cs
...............\.........\......\......\.........\frmViewBooks.Designer.cs
...............\.........\......\......\.........\frmViewBooks.resx
...............\.........\......\......\.........\frmViewCustomers.cs
...............\.........\......\......\.........\frmViewCustomers.Designer.cs
...............\.........\......\......\.........\frmViewCustomers.resx
...............\.........\......\......\.........\frmViewTransactions.cs
...............\.........\......\......\.........\frmViewTransactions.Designer.cs
...............\.........\......\......\.........\frmViewTransactions.resx
...............\.........\......\......\.........\LibraryDB.csproj
...............\.........\......\......\.........\LibraryDB.csproj.user
...............\.........\......\......\.........\MDIMAINFORM.cs
...............\.........\......\......\.........\MDIMAINFORM.Designer.cs
...............\.........\......\......\.........\MDIMAINFORM.resx
...............\.........\......\......\.........\Program.cs
...............\.........\......\......\.........\Properties
...............\.........\......\......\.........\..........\AssemblyInfo.cs
...............\.........\......\......\.........\..........\Resources.Designer.cs
...............\.........\......\......\.........\..........\Resources.resx
...............\.........\......\......\.........\..........\Settings.Designer.cs
...............\.........\......\......\.........\..........\Settings.settings
...............\.........\......\......\.........\SearchClass.cs
...............\.........\......\......\.........\TransactionClass.cs
...............\.........\......\......\LibraryDB.sln
...............\.........\LibraryDB
...............\.........\.........\bin
...............\.........\.........\...\Debug
...............\.........\.........\...\.....\11112008.txt
...............\.........\.........\...\.....\161120

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