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GroupDocs.Parser provides the functionality to extract data from databases via ADO.NET. This feature allows you to parse database tables and extract their content as text, similar to how you would extract data from document files.
The Parser class provides constructors specifically for database extraction:
// Constructor with DbConnection (recommended for .NET Core/.NET 5+)
Parser(DbConnection connection);
Parser(DbConnection connection, ParserSettings parserSettings);
// Constructor with connection string (only for .NET Framework)
Parser(string connectionString, LoadOptions loadOptions);
| Parameter | Type | Description |
|---|---|---|
connection | DbConnection | An active ADO.NET database connection object |
connectionString | string | Database connection string (only supported in .NET Framework) |
loadOptions | LoadOptions | Must be set to FileFormat.Database when using connection string |
parserSettings | ParserSettings | Optional settings for logging and other parser configurations |
- GetToc() returns
IEnumerable<TocItem>where eachTocItemrepresents a database table - GetText(int pageIndex) returns
TextReadercontaining the table data for the specified table index - Features.Text and Features.Toc properties indicate if text and table extraction are supported
GroupDocs.Parser works with any ADO.NET-compatible database provider. Common providers include:
- SQLite - Requires
System.Data.SQLiteNuGet package - SQL Server - Built-in support via
System.Data.SqlClient - MySQL - Requires
MySql.DataNuGet package - PostgreSQL - Requires
NpgsqlNuGet package - Oracle - Requires
Oracle.ManagedDataAccessNuGet package
- Database extraction is primarily for text-based table content
- Complex relationships between tables are not automatically resolved
- Only table data can be extracted, not views or stored procedures
- The connection string method is only available in .NET Framework
The DbConnection approach is the recommended method and works with all .NET platforms (.NET Framework, .NET Core, .NET 5+).
// Basic constructor
Parser(DbConnection connection);
// With parser settings (for logging, etc.)
Parser(DbConnection connection, ParserSettings parserSettings)
The second constructor allows you to use ParserSettings object to control the process; for example, by adding logging functionality.
Here are the steps to extract data from a database:
- Prepare DbConnection object;
- Instantiate Parser object with connection string;
- Call Features.Text property to check if text extraction is supported;
- Call Features.Toc property to check if table of contents extraction is supported;
- Call GetToc method and obtain collection of tables;
- Iterate through the collection and get a text from tables.
The following example shows how to extract data from a SQLite database:
using System.Data.Common;
using System.Data.SQLite;
using GroupDocs.Parser;
using GroupDocs.Parser.Data;
// Connection string for SQLite database
string dbPath = "sample.db";
string connectionString = $"Data Source={dbPath};Version=3;";
// Create DbConnection object
using (DbConnection connection = new SQLiteConnection(connectionString))
{
connection.Open();
// Create an instance of Parser class to extract tables from the database
using (Parser parser = new Parser(connection))
{
// Check if text extraction is supported
if (!parser.Features.Text)
{
Console.WriteLine("Text extraction isn't supported for this database.");
return;
}
// Check if table of contents (table list) extraction is supported
if (!parser.Features.Toc)
{
Console.WriteLine("Table of contents extraction isn't supported.");
return;
}
// Get a list of all tables in the database
IEnumerable<TocItem> tables = parser.GetToc();
// Iterate over each table
foreach (TocItem table in tables)
{
Console.WriteLine($"\n=== Table: {table.Text} ===");
// Extract table content as text
// PageIndex represents the table index
using (TextReader reader = parser.GetText(table.PageIndex.Value))
{
if (reader != null)
{
string tableContent = reader.ReadToEnd();
Console.WriteLine(tableContent);
}
else
{
Console.WriteLine("Unable to extract data from this table.");
}
}
}
}
}
using System.Data.Common;
using System.Data.SqlClient;
using GroupDocs.Parser;
string connectionString = "Server=localhost;Database=MyDatabase;Integrated Security=true;";
using (DbConnection connection = new SqlConnection(connectionString))
{
connection.Open();
using (Parser parser = new Parser(connection))
{
if (parser.Features.Text && parser.Features.Toc)
{
foreach (TocItem table in parser.GetToc())
{
Console.WriteLine($"Extracting from table: {table.Text}");
using (TextReader reader = parser.GetText(table.PageIndex.Value))
{
if (reader != null)
{
Console.WriteLine(reader.ReadToEnd());
}
}
}
}
}
}
WarningImportant: This functionality is supported only in .NET Framework version of GroupDocs.Parser for .NET. For .NET Core, .NET 5+, or cross-platform applications, use theDbConnectionapproach described above.
To create an instance of Parser class to extract data from a database using a connection string, use:
Parser(string connectionString, LoadOptions loadOptions);
- connectionString: The database connection string (not a file path)
- loadOptions: Must be initialized with
FileFormat.Database
The list of tables is represented as table of contents (TOC). Each table can be extracted using the GetText(int) method where the integer parameter is the table index from the TOC.
Here are the steps to extract data from Sqlite database:
- Prepare connection string;
- Instantiate Parser object with connection string;
- Call Features.Text property to check if text extraction is supported;
- Call Features.Toc property to check if table of contents extraction is supported;
- Call GetToc method and obtain collection of tables;
- Iterate through the collection and get a text from tables.
using GroupDocs.Parser;
using GroupDocs.Parser.Options;
string databasePath = "sample.db";
string connectionString = string.Format(
"Provider=System.Data.Sqlite;Data Source={0};Version=3;",
databasePath
);
// Create an instance of Parser class to extract tables from the database
// Pass connection string as first parameter and LoadOptions with FileFormat.Database
using (Parser parser = new Parser(connectionString, new LoadOptions(FileFormat.Database)))
{
// Check if text extraction is supported
if (!parser.Features.Text)
{
Console.WriteLine("Text extraction isn't supported.");
return;
}
// Check if table of contents extraction is supported
if (!parser.Features.Toc)
{
Console.WriteLine("Table of contents extraction isn't supported.");
return;
}
// Get a list of all tables in the database
IEnumerable<TocItem> tables = parser.GetToc();
// Iterate over tables
foreach (TocItem table in tables)
{
// Print the table name
Console.WriteLine($"\nTable: {table.Text}");
// Extract table content as text using the table's page index
using (TextReader reader = parser.GetText(table.PageIndex.Value))
{
if (reader != null)
{
Console.WriteLine(reader.ReadToEnd());
}
}
}
}
You may easily run the code above and see the feature in action in our GitHub examples:
Along with full featured .NET library we provide simple, but powerful free Apps.
You are welcome to parse documents and extract data from PDF, DOC, DOCX, PPT, PPTX, XLS, XLSX, Emails and more with our free online Free Online Document Parser App.
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