/// <summary>
/// Generates a UPDATE query that applies a set of values passed with a
/// anonymous object, to a set of rows that fulfill the passed <see cref="IQueryCondition"/>.
/// It is mandatory to use a anonymous object that only contains the Properties
/// that should be updated, because a passed domain-object would result in a query
/// updating all columns and that is not the desired behaviour most of the time.
/// </summary>
/// <param name="objectContainingChanges">the anonymous object containig the updated values</param>
/// <param name="updateCondition">the condition, which rows should be updated</param>
/// <returns>a query-<see cref="string"/> and a <see cref="QueryParameter[]"/>
/// that contains the updated values and the values used in the WHERE clause.
/// Both types of parameters are sanitized.</returns>
public (string query, QueryParameter[] queryParameters) GenerateUpdateQuery(
object objectContainingChanges,
IQueryCondition updateCondition)
{
if (updateCondition is null)
{
throw new ArgumentNullException(nameof(updateCondition));
}
if (objectContainingChanges is null)
{
throw new ArgumentNullException(nameof(objectContainingChanges));
}
if (objectContainingChanges.GetType() == typeof(T))
{
throw new InvalidOperationException(
"You are not allowed to pass the domain object itself" +
" -> pass a anonymous object containing the changes to apply");
}
foreach (var currentProperty in objectContainingChanges.GetType().GetProperties())
{
if (currentProperty.Name == "Id")
{
throw new InvalidOperationException(
"Attempted to update Id column -> forbidden operation");
}
else if (!typeof(T).GetProperties().Any(p => p.Name == currentProperty.Name))
{
throw new InvalidOperationException(
$"Property {currentProperty.Name} does not exist for type {typeof(T).Name}");
}
var correctType = typeof(T).GetProperties()
.First(p => p.Name == currentProperty.Name)
.PropertyType;
if (!(correctType == currentProperty.PropertyType))
{
throw new InvalidOperationException(
$"Property-Type mismatch of property {currentProperty.Name}; " +
$"expected type {correctType.FullName}, actual type {currentProperty.PropertyType.FullName}");
}
}
var queryStringBuilder = new StringBuilder();
var queryParameters = new List <QueryParameter>();
queryStringBuilder.Append($"UPDATE [Hurace].[{typeof(T).Name}] SET");
AppendColumnValuesWithAssignment(queryStringBuilder, queryParameters, objectContainingChanges);
queryStringBuilder.Append(" WHERE ");
updateCondition.AppendTo(queryStringBuilder, queryParameters);
return(queryStringBuilder.ToString(), queryParameters.ToArray());
}
/// <summary>
/// Generates a DELETE query that removes all rows from the db, that fulfill
/// a passed condition.
/// </summary>
/// <param name="deleteCondition">if a row fulfills this condition, the generated query will delete it.</param>
/// <returns>a query-<see cref="string"/> and a <see cref="QueryParameter[]"/> that
/// contains all parameters used in the WHERE-clause in a sanitized way.</returns>
public (string query, QueryParameter[] queryParameters) GenerateDeleteQuery(IQueryCondition deleteCondition)
{
if (deleteCondition is null)
{
throw new ArgumentNullException(nameof(deleteCondition));
}
var queryStringBuilder = new StringBuilder();
var queryParameters = new List <QueryParameter>();
queryStringBuilder.Append($"DELETE FROM [Hurace].[{typeof(T).Name}] WHERE ");
deleteCondition.AppendTo(queryStringBuilder, queryParameters);
return(queryStringBuilder.ToString(), queryParameters.ToArray());
}
/// <summary>
/// Generates a SELECT query that supplies the executer with either all rows, or rows
/// that fall into passed rules
/// </summary>
/// <param name="selectCondition">gets transformed into a where clause</param>
/// <returns>a <see cref="ValueTuple{string, QueryParameter[]}" containing the
/// select query as a string and optionally the parameters of the
/// passed condition/>a query-<see cref="string"/> and a <see cref="QueryParameter[]"/>
/// that contains the sanitized values of the passed <see cref="IQueryCondition"/></returns>
public (string query, QueryParameter[] queryParameters) GenerateSelectQuery(IQueryCondition selectCondition = null)
{
var queryStringBuilder = new StringBuilder();
queryStringBuilder.Append("SELECT ");
AppendColumnNames(queryStringBuilder);
queryStringBuilder.Append($" FROM [Hurace].[{typeof(T).Name}]");
var queryParameters = new List <QueryParameter>();
if (selectCondition != null)
{
queryStringBuilder.Append(" WHERE ");
selectCondition.AppendTo(queryStringBuilder, queryParameters);
}
return(queryStringBuilder.ToString(), queryParameters.ToArray());
}
