/// <summary>
/// Returns rows count from specified table in an asynchronous manner.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public virtual async Task <int> CountAsync <T>() where T : class
{
var tableName = AttributeExtension.TableNameAttributeValidate(typeof(T));
var query = $"SELECT COUNT(*) FROM {tableName}";
var count = await this.ExecuteScalarAsync <int>(query).ConfigureAwait(false);
return(count);
}
/// <summary>
/// Returns rows count from specified table.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public virtual int Count <T>() where T : class
{
var tableName = AttributeExtension.TableNameAttributeValidate(typeof(T));
var query = $"SELECT COUNT(*) FROM {tableName}";
var count = this.ExecuteScalar <int>(query);
return(count);
}
/// <summary>
/// Returns rows count from specified table.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public static int Count <T>(this IDatabaseConnector connector) where T : class
{
var con = connector as DatabaseConnectorBase;
if (con == null)
{
throw new InvalidCastException($"{connector.GetType().FullName} cannot be use with this extension (expected to get instance of {typeof(DatabaseConnectorBase).FullName}");
}
var tableName = AttributeExtension.TableNameAttributeValidate(typeof(T));
var query = $"SELECT COUNT(*) FROM {tableName}";
var count = con.ExecuteScalar(query);
var countAsString = count.ToString();
return(int.Parse(countAsString));
}
/// <summary>
/// Returns rows count on specific condition from specified table.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <returns></returns>
public static int Count <T>(this IDatabaseConnector connector, Expression <Func <T, bool> > predicate) where T : class
{
var con = connector as DatabaseConnectorBase;
if (con == null)
{
throw new InvalidCastException($"{connector.GetType().FullName} cannot be use with this extension (expected to get instance of {typeof(DatabaseConnectorBase).FullName}");
}
var tableName = AttributeExtension.TableNameAttributeValidate(typeof(T));
var exprTranslator = new ExpressionTranslator <T>(con.CompatibleFunctionName);
var translateResult = exprTranslator.Translate(predicate);
var query = $"SELECT COUNT(*) FROM {tableName} WHERE {translateResult.Expression}";
var count = con.ExecuteScalar(query, translateResult.Parameters);
var countAsString = count.ToString();
return(int.Parse(countAsString));
}
