Flat File Source Component

The Flat File source component in SQL Server Integration Services (SSIS) is used to extract data from flat files, such as text files (.txt), comma-separated value files (.csv), and tab-delimited files.

Purpose and Usage

This component is fundamental for data ingestion from external sources that are not stored in relational databases. It provides flexibility in handling various file formats and delimiters, allowing you to seamlessly integrate data from flat files into your SSIS data flow.

Key Features

File Format Support: Handles delimited files (fixed-width and variable-width), with support for various row and column delimiters.
Codepage Configuration: Allows specifying the codepage of the source file to ensure correct character interpretation.
Header Row Support: Can be configured to skip header rows, using the first row as column names.
Text Qualifier: Supports text qualifiers to handle fields containing delimiter characters.
Error Handling: Configurable error output for rows that cannot be parsed correctly.

Configuration Steps

Add a Flat File Source component to your Data Flow Task.
Double-click the component to open the Flat File Source Editor.
Connection Manager: Create a new Flat File Connection Manager or select an existing one.
File Format Properties: Within the Connection Manager, configure properties like:
- File Name: The path to the source flat file.
- Format: Delimited, Fixed width, or Ragged right.
- Text Qualifier: Character used to enclose fields containing delimiters (e.g., double quotes).
- Header row delimiter: The character that separates columns in the header row.
- Header rows to skip: Number of rows to skip at the beginning of the file (usually 1 if a header exists).
Columns: Define the columns and their data types. You can preview the data to ensure correct parsing.
Advanced/Error Output: Configure advanced parsing settings and error handling behavior.

Example Configuration (CSV File)

Consider a CSV file named Customers.csv with the following content:

                "CustomerID","FirstName","LastName","Email"
1,"John","Doe","john.doe@example.com"
2,"Jane","Smith","jane.smith@example.com"
            

To configure the Flat File Source for this file:

File Name: C:\Data\Customers.csv
Format: Delimited
Header row delimiter: Comma (,)
Header rows to skip: 1
Column names in first data row: Checked
Text Qualifier: Double quote (")

Table of Properties

Property	Description	Data Type
`Format`	Specifies the file format: Delimited, Fixed width, or Ragged right.	Enumeration
`HeaderRowsToSkip`	The number of rows to skip at the beginning of the file.	Integer
`ColumnNamesInFirstDataRow`	Indicates whether the first data row contains column names.	Boolean
`TextQualifier`	The character used to enclose fields that may contain delimiter characters.	String
`RowDelimiter`	The character(s) that mark the end of a row.	String
`ColumnDelimiter`	The character(s) that separate columns.	String

Best Practices

Ensure consistent file encoding (e.g., UTF-8) for all flat files.
Use a separate Flat File Connection Manager for each unique file format or location.
Thoroughly test your configuration with sample data to catch parsing errors early.
Configure error outputs to redirect problematic rows to a separate destination for analysis.