Converting Excel sheet into an MS SQL Express database using C#


In many real-world scenarios, you might have data stored in Excel spreadsheets that you want to move into a more robust and scalable database like Microsoft SQL Server Express. This can help you centralize your data, improve data integrity, and enable more advanced querying and reporting. In this tutorial, we'll guide you through the steps to transform an existing Excel sheet into an MS SQL Express database using C#.

1. Install Required Libraries

Ensure that your C# project has the necessary libraries installed. You'll need two important namespaces

  • System.Data.SqlClient: For working with SQL Server.
  • System.Data.OleDb: For working with Excel files.

You can install these libraries via NuGet if they are not already included in your project.

2. Create a SQL Server Database

If you haven't already, install SQL Server Express on your machine and create a new database where you want to import the Excel data. Make note of your database name as you'll need it later.

3. Connect to SQL Server

Create a connection string to connect to your SQL Server Express database. Replace YourDatabaseName with the name of your SQL database.

string connectionString = "Server=localhost\\SQLEXPRESS;Database=YourDatabaseName;Trusted_Connection=True;";

4. Read Excel Data

Use the OleDbConnection and OleDbDataAdapter classes to read data from the Excel sheet. Replace YourExcelFile.xlsx" with the path to your Excel file and Sheet1"with the actual sheet name.

string excelConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=YourExcelFile.xlsx;Extended Properties=\"Excel 12.0 Xml;HDR=YES;\"";
using (OleDbConnection excelConnection = new OleDbConnection(excelConnectionString))
    string query = "SELECT * FROM [Sheet1$]"; // Replace Sheet1 with the actual sheet name.
    OleDbDataAdapter dataAdapter = new OleDbDataAdapter(query, excelConnection);
    DataSet dataSet = new DataSet();

5. Create SQL Table

You'll need to create a corresponding SQL table with the same schema as your Excel sheet. You can do this using SQL commands. Replace YourTableName and define your table structure.

using (SqlConnection sqlConnection = new SqlConnection(connectionString))
    string createTableQuery = "CREATE TABLE YourTableName (Column1 DataType, Column2 DataType, ...)"; // Define your table structure.
    SqlCommand createTableCommand = new SqlCommand(createTableQuery, sqlConnection);

6. Insert Data into SQL Table

Loop through the rows of your Excel sheet and insert them into the SQL table. Replace YourTableName with your actual table name and add parameters for your table columns.

using (SqlConnection sqlConnection = new SqlConnection(connectionString))
    foreach (DataRow row in dataSet.Tables[0].Rows)
        string insertQuery = "INSERT INTO YourTableName (Column1, Column2, ...) VALUES (@Column1, @Column2, ...)"; // Define your INSERT query.
        SqlCommand insertCommand = new SqlCommand(insertQuery, sqlConnection);
        // Add parameters and set values based on the Excel data.
        insertCommand.Parameters.AddWithValue("@Column1", row["Column1"]);
        insertCommand.Parameters.AddWithValue("@Column2", row["Column2"]);
        // Add more parameters as needed for your table columns.

This code assumes that the first row in your Excel sheet contains headers (HDR=YES).

Make sure to handle exceptions and errors appropriately and add error checking and validation for production use.

This process can be automated and integrated into your applications for data migration and analysis.