What does the library
Bodoconsult.Core.Database.Sqlite library simplifies the access to Sqlite3 based databases. It handles the most common database actions like getting datatables, running SQL statement or fetch scalar values from the database.
Additionally the library contains some tools for developers making the usage of the database layers derived from Bodoconsult.Core.Database as easy as possible. See below.
How to use the library
The source code contain a NUnit test classes, the following source code is extracted from. The samples below show the most helpful use cases for the library.
The database used for unit tests is the Chinook sample database from https://github.com/lerocha/chinook-database.
Connection string to Sqlite3
To connect to a Sqlite3 database with this library you need to provide connection string. Here a sample for such a connection string:
Data Source=c:\mydb.db;Version=3;
For more information on connection strings see https://www.connectionstrings.com/sqlite/.
If the database file called in the connection string is not existing, a new empty database file is created.
Class overview and main methods
The most important class in the library is the the class SqliteConnManager. SqliteConnManager exposes the following main methods:
Connection related and general methods
- TestConnection()
- GetCommand()
- GetParameter()
Methods for running SQL statements or commands
- Exec()
- ExecMultiple()
Methods for getting data
- GetDataTable()
- GetDataReader()
- GetDataAdapter()
Samples
[TestFixture]
public class UnitTestSqliteConnManager
{
private IConnManager _db;
[SetUp]
public void Setup()
{
var conn = TestHelper.SqliteConnectionString;
_db = SqliteConnManager.GetConnManager(conn);
}
[Test]
public void TestTestConnection()
{
// Assert
// Act
var result = _db.TestConnection();
// Assert
Assert.IsTrue(result);
}
[Test]
public void TestGetDataTableSql()
{
// Assert
var sql = "SELECT * FROM \"Customer\";";
// Act
var result = _db.GetDataTable(sql);
// Assert
Assert.IsNotNull(result);
}
[Test]
public void TestGetDataTableCommand()
{
// Act
var sql =
"SELECT * FROM \"Customer\"; ";
var cmd = new SqliteCommand(sql);
// Act
var result = _db.GetDataTable(cmd);
// Assert
Assert.IsNotNull(result);
}
/// <summary>
/// Get a datatable from the database from a (parameterized) SqlCommand object (choose this option to avoid SQL injection)
/// </summary>
[Test]
public void TestGetDataTableFromCommandWithGetCommand()
{
const string sql = "SELECT * FROM Customer";
var cmd = _db.GetCommand();
cmd.CommandText = sql;
// Add parameters here if required
var erg = _db.GetDataTable(cmd);
Assert.IsTrue(erg.Rows.Count > 0);
}
/// <summary>
/// Get a datatable from the database from a plain SQL string (avoid this option due to SQL injection)
/// </summary>
[Test]
public void TestGetDataReaderFromSql()
{
const string sql = "SELECT * FROM \"Customer\"";
var erg = _db.GetDataReader(sql);
Assert.IsTrue(erg.FieldCount > 0);
}
/// <summary>
/// Get a datatable from the database from a (parameterized) SqlCommand object (choose this option to avoid SQL injection)
/// </summary>
[Test]
public void TestGetDataReaderFromCommand()
{
const string sql = "SELECT * FROM \"Customer\"";
var cmd = new SqliteCommand
{
CommandText = sql
};
// Add parameters here if required
var erg = _db.GetDataReader(cmd);
Assert.IsTrue(erg.FieldCount > 0);
}
/// <summary>
/// Get a datatable from the database from a (parameterized) SqlCommand object (choose this option to avoid SQL injection)
/// </summary>
[Test]
public void TestGetDataReaderFromCommandWidthGetCommand()
{
const string sql = "SELECT * FROM \"Customer\"";
var cmd = _db.GetCommand();
cmd.CommandText = sql;
// Add parameters here if required
var erg = _db.GetDataReader(cmd);
Assert.IsTrue(erg.FieldCount > 0);
}
/// <summary>
/// Get a datatable from the database from a (parameterized) SqlCommand object (choose this option to avoid SQL injection)
/// </summary>
[Test]
public void TestGetDataReaderFromCommandWidthGetCommandAndParameter()
{
const string sql = "SELECT * FROM \"Customer\" WHERE \"CustomerId\"=@ID;";
var cmd = _db.GetCommand();
cmd.CommandText = sql;
var p = _db.GetParameter(cmd, "@ID", GeneralDbType.Int);
p.Value = 8;
// Add parameters here if required
var erg = _db.GetDataReader(cmd);
Assert.IsTrue(erg.FieldCount > 0);
Assert.IsTrue(erg.HasRows);
}
/// <summary>
/// Execute a plain SQL string (avoid this option due to SQL injection)
/// </summary>
[Test]
public void TestExecFromSql()
{
const string sql = "DELETE FROM Customer WHERE CustomerId=-99";
Assert.DoesNotThrow(() => _db.Exec(sql));
}
/// <summary>
/// Execute a SqlCommand object (choose this option to avoid SQL injection)
/// </summary>
[Test]
public void TestExecFromCommand()
{
const string sql = "DELETE FROM \"Customer\" WHERE \"CustomerId\"=@Key";
// Create command
var cmd = new SqliteCommand()
{
CommandText = sql
};
// Add a parameter to the command
var para = cmd.Parameters.Add("@Key", SqliteType.Integer);
para.Value = -99;
Assert.DoesNotThrow(() => _db.Exec(cmd));
}
/// <summary>
/// Get a scalar value from database from a plain SQL string (avoid this option due to SQL injection)
/// </summary>
[Test]
public void TestExecWithResultFromSql()
{
const string sql = "SELECT \"CustomerId\" FROM \"Customer\" WHERE \"CustomerId\"=8;";
var result = _db.ExecWithResult(sql);
Assert.IsNotNull(result);
Assert.IsFalse(string.IsNullOrEmpty(result));
}
/// <summary>
/// Get a scalar value from database from SqlCommand object (choose this option to avoid SQL injection)
/// </summary>
[Test]
public void TestExecWithResultFromCommand()
{
const string sql = "SELECT \"CustomerId\" FROM \"Customer\" WHERE \"CustomerId\"=@Key";
// Create command
var cmd = new SqliteCommand
{
CommandText = sql
};
// Add a parameter to the command
var para = cmd.Parameters.Add("@Key", SqliteType.Integer);
para.Value = 8;
var result = _db.ExecWithResult(cmd);
Assert.IsNotNull(result);
Assert.IsFalse(string.IsNullOrEmpty(result));
}
[Test]
public void TestExecMultiple()
{
const string sql = "DELETE FROM \"Customer\" WHERE \"CustomerId\"=-99";
var commands = new List<DbCommand>();
var cmd = new SqliteCommand(sql);
commands.Add(cmd);
cmd = new SqliteCommand(sql);
commands.Add(cmd);
cmd = new SqliteCommand(sql);
commands.Add(cmd);
var result = _db.ExecMultiple(commands);
Assert.IsTrue(result == 0);
}
[TestCase(GeneralDbType.Int, SqliteType.Integer)]
[TestCase(GeneralDbType.Decimal, SqliteType.Real)]
[TestCase(GeneralDbType.Float, SqliteType.Real)]
[TestCase(GeneralDbType.Text, SqliteType.Text)]
public void Test(GeneralDbType inpuType, SqliteType expectedType)
{
// Arrange
// Act
var result = SqliteConnManager.MapGeneralDbTypeToSqliteType(inpuType);
// Assert
Assert.AreEqual(expectedType, result);
}
}
Developer tools for making best usage of Bodoconsult.Core.Database based data layers
There is as basic metadata infrastructure implemented to help developers to make best usage of Bodoconsult.Core.Database. This metadata infrastructure derived from IMetaDataService / BaseMetaDataService creates C# code files based on a certain SQL statement OR DBCommand object.
- It first creates an adjusted entity class for the SQL statement OR DBCommand object.
- Then it creates a mapping method to map a DataReader row object to the entity class.
- At last it creates an service class for adding new rows, updating rows and getting rows from the database table related to SQL statement OR DBCommand object. This feature works only well for statements absed on a single table. If there are more tables targeted in the statement, only the GetAll and GetById may make sense in the service class. The other methods ma be removed in that case.
Here a sample how to use the IMetaDataService infrastructure:
const string conn = "Valid ADO.NET provider connection string";
const string sql = "SELECT * FROM \"Customer\";";
const string entityName = "Customer";
const string primaryKeyField = "CustomerId";
const string targetPath = @"D:\temp";
// Instanciate the metadata service
var service = SqliteMetaDataService();
// Get the metadata for the SQL statement
service.GetMetaData(conn, entityName, sql, primaryKeyField);
// Export the code files
var result = service.ExportAll(targetPath);
As a result you will find four files with code in the folder D:\temp:
- D:\temp\Customer_EntityClass_Code.txt
- D:\temp\Customer_DataHelperMethod_Code.txt
- D:\temp\Customer_ServiceClass_Code.txt
- D:\temp\Customer_TestDataHelperMethod_Code.txt
About us
Bodoconsult (http://www.bodoconsult.de) is a Munich based software development company from Germany.
Robert Leisner is senior software developer at Bodoconsult. See his profile on http://www.bodoconsult.de/Curriculum_vitae_Robert_Leisner.pdf.
