public static SqlPredicate Parse(Expression expression)
{
var methodCallExpression = expression as MethodCallExpression;
if (methodCallExpression != null)
{
if (methodCallExpression.Method.Name == nameof(string.Contains))
{
var memberExpression = methodCallExpression.Object as MemberExpression;
return(QB.Like(memberExpression.Member.Name, Expression.Lambda(methodCallExpression.Arguments.First()).Compile().DynamicInvoke()));
}
else
{
throw new Exception($"Unsupported method {methodCallExpression.Method.Name} in expression {expression}.");
}
}
var binaryExpression = expression as BinaryExpression;
if (binaryExpression == null)
{
throw new Exception($"Unsupported expression {expression}.");
}
switch (binaryExpression.NodeType)
{
case ExpressionType.AndAlso:
return(QB.And(Parse(binaryExpression.Left), Parse(binaryExpression.Right)));
case ExpressionType.OrElse:
return(QB.Or(Parse(binaryExpression.Left), Parse(binaryExpression.Right)));
case ExpressionType.NotEqual:
var nameAndValue0 = GetColumnNameAndParameterValue(binaryExpression);
return(QB.NEq(nameAndValue0.Item1, nameAndValue0.Item2));
case ExpressionType.Equal:
var nameAndValue1 = GetColumnNameAndParameterValue(binaryExpression);
return(QB.Eq(nameAndValue1.Item1, nameAndValue1.Item2));
case ExpressionType.LessThan:
var nameAndValue2 = GetColumnNameAndParameterValue(binaryExpression);
return(QB.Le(nameAndValue2.Item1, nameAndValue2.Item2));
case ExpressionType.LessThanOrEqual:
var nameAndValue3 = GetColumnNameAndParameterValue(binaryExpression);
return(QB.LEq(nameAndValue3.Item1, nameAndValue3.Item2));
case ExpressionType.GreaterThan:
var nameAndValue4 = GetColumnNameAndParameterValue(binaryExpression);
return(QB.Gr(nameAndValue4.Item1, nameAndValue4.Item2));
case ExpressionType.GreaterThanOrEqual:
var nameAndValue5 = GetColumnNameAndParameterValue(binaryExpression);
return(QB.GEq(nameAndValue5.Item1, nameAndValue5.Item2));
default:
throw new Exception($"Unsupported expression {expression}.");
}
}
public TEntity Load <TEntity>(object id) where TEntity : new()
{
if (id is SqlPredicate)
{
throw new ArgumentException("Entity id was expected but SqlPredicate found. You probably wanted to use Load<TEntity>(QueryBuilder.Create().SetWhereStatement(sqlPredicate)).");
}
MappingAttribute identityMapping = FindIdentity <TEntity>();
if (identityMapping == null)
{
throw new Exception(string.Format("Entity {0} has no primary key defined.", typeof(TEntity).Name));
}
var results = Load <TEntity>(QueryBuilder.Create().SetWhereStatement(QB.Eq(identityMapping.Name, id)));
if (results.Count > 1)
{
throw new Exception(string.Format("There is more than one record with id {0} of entity {1}.", id, typeof(TEntity).Name));
}
return(results.FirstOrDefault());
}