Saturday, October 13, 2012

How to import data from Excel to SQL Server

This step-by-step article demonstrates how to import data from Microsoft Excel worksheets into Microsoft SQL Server databases by using a variety of methods.

Description of the Technique

The samples in this article import Excel data by using:
  • SQL Server Data Transformation Services (DTS)
  • Microsoft SQL Server 2005 Integration Services (SSIS)
  • SQL Server linked servers
  • SQL Server distributed queries
  • ActiveX Data Objects (ADO) and the Microsoft OLE DB Provider for SQL Server
  • ADO and the Microsoft OLE DB Provider for Jet 4.0

Requirements

The following list outlines the recommended hardware, software, network infrastructure, and service packs that are required:
  • Available instance of Microsoft SQL Server 7.0 or Microsoft SQL Server 2000 or Microsoft SQL Server 2005
  • Microsoft Visual Basic 6.0 for the ADO samples that use Visual Basic
Portions of this article assume that you are familiar with the following topics:
  • Data Transformation Services
  • Linked servers and distributed queries
  • ADO development in Visual Basic

Samples

Import vs. Append

The sample SQL statements that are used in this article demonstrate Create Table queries that import Excel data into a new SQL Server table by using the SELECT...INTO...FROM syntax. You can convert these statements to Append queries by using the INSERT INTO...SELECT...FROM syntax while you continue to reference the source and destination objects as shown in these code samples.

Use DTS or SSIS

You can use the SQL Server Data Transformation Services (DTS) Import Wizard or the SQL Server Import and Export Wizard to import Excel data into SQL Server tables. When you are stepping through the wizard and selecting the Excel source tables, remember that Excel object names that are appended with a dollar sign ($) represent worksheets (for example, Sheet1$), and that plain object names without the dollar sign represent Excel named ranges.

Use a Linked Server

To simplify queries, you can configure an Excel workbook as a linked server in SQL Server. For additional information, The following code imports the data from the Customers worksheet on the Excel linked server "EXCELLINK" into a new SQL Server table named XLImport1:
SELECT * INTO XLImport1 FROM EXCELLINK...[Customers$]
    
You can also execute the query against the source in a passthrough manner by using OPENQUERY as follows:
SELECT * INTO XLImport2 FROM OPENQUERY(EXCELLINK,
    'SELECT * FROM [Customers$]')
    

Use Distributed Queries

If you do not want to configure a persistent connection to the Excel workbook as a linked server, you can import data for a specific purpose by using the OPENDATASOURCE or the OPENROWSET function. The following code samples also import the data from the Excel Customers worksheet into new SQL Server tables:
SELECT * INTO XLImport3 FROM OPENDATASOURCE('Microsoft.Jet.OLEDB.4.0',
'Data Source=C:\test\xltest.xls;Extended Properties=Excel 8.0')...[Customers$]

SELECT * INTO XLImport4 FROM OPENROWSET('Microsoft.Jet.OLEDB.4.0',
'Excel 8.0;Database=C:\test\xltest.xls', [Customers$])

SELECT * INTO XLImport5 FROM OPENROWSET('Microsoft.Jet.OLEDB.4.0',
'Excel 8.0;Database=C:\test\xltest.xls', 'SELECT * FROM [Customers$]')
    

Use ADO and SQLOLEDB

When you are connected to SQL Server in an ADO application by using Microsoft OLE DB for SQL Server (SQLOLEDB), you can use the same "distributed query" syntax from the Using Distributed Queries section to import Excel data into SQL Server.

The following Visual Basic 6.0 code sample requires that you add a project reference to ActiveX Data Objects (ADO). This code sample also demonstrates how to use OPENDATASOURCE and OPENROWSET over an SQLOLEDB connection.
    Dim cn As ADODB.Connection
    Dim strSQL As String
    Dim lngRecsAff As Long
    Set cn = New ADODB.Connection
    cn.Open "Provider=SQLOLEDB;Data Source=<server>;" & _
        "Initial Catalog=<database>;User ID=<user>;Password=<password>"

    'Import by using OPENDATASOURCE.
    strSQL = "SELECT * INTO XLImport6 FROM " & _
        "OPENDATASOURCE('Microsoft.Jet.OLEDB.4.0', " & _
        "'Data Source=C:\test\xltest.xls;" & _
        "Extended Properties=Excel 8.0')...[Customers$]"
    Debug.Print strSQL
    cn.Execute strSQL, lngRecsAff, adExecuteNoRecords
    Debug.Print "Records affected: " & lngRecsAff

    'Import by using OPENROWSET and object name.
    strSQL = "SELECT * INTO XLImport7 FROM " & _
        "OPENROWSET('Microsoft.Jet.OLEDB.4.0', " & _
        "'Excel 8.0;Database=C:\test\xltest.xls', " & _
        "[Customers$])"
    Debug.Print strSQL
    cn.Execute strSQL, lngRecsAff, adExecuteNoRecords
    Debug.Print "Records affected: " & lngRecsAff

    'Import by using OPENROWSET and SELECT query.
    strSQL = "SELECT * INTO XLImport8 FROM " & _
        "OPENROWSET('Microsoft.Jet.OLEDB.4.0', " & _
        "'Excel 8.0;Database=C:\test\xltest.xls', " & _
        "'SELECT * FROM [Customers$]')"
    Debug.Print strSQL
    cn.Execute strSQL, lngRecsAff, adExecuteNoRecords
    Debug.Print "Records affected: " & lngRecsAff

    cn.Close
    Set cn = Nothing
    

Use ADO and the Jet Provider

The sample in the preceding section uses ADO with the SQLOLEDB Provider to connect to the destination of your Excel-to-SQL import. You can also use the OLE DB Provider for Jet 4.0 to connect to the Excel source.

The Jet database engine can reference external databases in SQL statements by using a special syntax that has three different formats:
  • [Full path to Microsoft Access database].[Table Name]
  • [ISAM Name;ISAM Connection String].[Table Name]
  • [ODBC;ODBC Connection String].[Table Name]
This section uses the third format to make an ODBC connection to the destination SQL Server database. You can use an ODBC Data Source Name (DSN) or a DSN-less connection string:
DSN:
    [odbc;DSN=<DSN name>;UID=<user>;PWD=<password>]

DSN-less:
   [odbc;Driver={SQL Server};Server=<server>;Database=<database>;
       UID=<user>;PWD=<password>]
    
The following Visual Basic 6.0 code sample requires that you add a project reference to ADO. This code sample demonstrates how to import Excel data to SQL Server over an ADO connection by using the Jet 4.0 Provider.
    Dim cn As ADODB.Connection
    Dim strSQL As String
    Dim lngRecsAff As Long
    Set cn = New ADODB.Connection
    cn.Open "Provider=Microsoft.Jet.OLEDB.4.0;" & _
        "Data Source=C:\test\xltestt.xls;" & _
        "Extended Properties=Excel 8.0"
    
    'Import by using Jet Provider.
    strSQL = "SELECT * INTO [odbc;Driver={SQL Server};" & _
        "Server=<server>;Database=<database>;" & _
        "UID=<user>;PWD=<password>].XLImport9 " & _
        "FROM [Customers$]"
    Debug.Print strSQL
    cn.Execute strSQL, lngRecsAff, adExecuteNoRecords
    Debug.Print "Records affected: " & lngRecsAff
        
    cn.Close
    Set cn = Nothing
    
You can also use this syntax, which the Jet Provider supports, to import Excel data into other Microsoft Access databases, indexed sequential access method (ISAM) ("desktop") databases, or ODBC databases.

Troubleshooting

  • Remember that Excel object names that are appended with a dollar sign ($) represent worksheets (for example, Sheet1$) and that plain object names represent Excel named ranges.
  • In some circumstances, especially when you designate the Excel source data by using the table name instead of a SELECT query, the columns in the destination SQL Server table are rearranged in alphabetical order.For additional information about this problem with the Jet Provider, click the article number below to view the article in the Microsoft Knowledge Base:
    PRB: Columns Are Sorted Alphabetically When You Use ADOX to Retrieve Columns of Access Table
  • When the Jet Provider determines that an Excel column contains mixed text and numeric data, the Jet Provider selects the "majority" data type and returns non-matching values as NULLs.For additional information about how to work around this problem, click the article number below to view the article in the Microsoft Knowledge Base:
     PRB: Excel Values Returned as NULL Using DAO OpenRecordset