/// <summary>
/// Represents a meaningful result from order by expressions
/// </summary>
/// <typeparam name="T">The type of the expression which belong to</typeparam>
/// <param name="expression">The expression of order by statement</param>
/// <returns></returns>
public static OrderByExpressionResult GetOrderByExpression <T>(object expression)
{
OrderByExpressionResult orderByExpressionResults = new OrderByExpressionResult();
if (expression is LambdaExpression)
{
LambdaExpression lambdaExpression = expression as LambdaExpression;
if (lambdaExpression.Body is MemberExpression)
{
MemberExpression memberExpression = lambdaExpression.Body as MemberExpression;
orderByExpressionResults.MemberName = memberExpression.Member.Name;
}
}
else if (expression is MemberExpression)
{
MemberExpression memberExpression = expression as MemberExpression;
if (memberExpression.NodeType == ExpressionType.MemberAccess)
{
orderByExpressionResults.MemberName = memberExpression.Member.Name;
}
else if (memberExpression.NodeType == ExpressionType.Convert)
{
orderByExpressionResults.MemberName = "";
}
}
else if (expression is UnaryExpression)
{
UnaryExpression unaryExpression = expression as UnaryExpression;
if (unaryExpression.Operand is MemberExpression)
{
MemberExpression memberExpression = unaryExpression.Operand as MemberExpression;
orderByExpressionResults.MemberName = memberExpression.Member.Name;
}
}
return(orderByExpressionResults);
}
public static void TestExpressions()
{
List <WhereExpressionResult> expressionResults = new List <WhereExpressionResult>();
string rawText = string.Empty;
Expression <Func <SampleEntity, bool> > expression = (x => x.Name == "Foo");
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expression.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expression = (x => !(x.Name == "Foo"));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expression.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionWithOr = (x => x.Name == "Foo" || x.Name == "Goo");
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithOr.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionWithAnd = (x => x.Name == "Foo" && x.Name.Length == 3);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithAnd.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionWithParentheses = (x => x.Name == "Foo" || (x.Name == "Goo" && x.Year == 2020));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithParentheses.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionWithParentheses = (x => !(x.Name == "Foo" || (x.Name == "Goo" && x.Year == 2020)));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithParentheses.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionWithParentheses = (x => (x.Name == "Foo" || x.Name == "Goo") && x.Year == 2020);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithParentheses.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionWithNotEqual = (x => x.Name != "Foo");
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithNotEqual.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionWithParenthesesNotEqual = (x => (x.Name != "Foo" && x.Name != "Goo") && x.Year == 2020);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionWithParenthesesNotEqual.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement(); // Result: ( ( Name != Foo and Name != Goo) and Year = 2020)
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionLessThan = (x => x.Year < 2020);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionLessThan.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionLessThan = (x => !(x.Year < 2020));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionLessThan.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionGreaterThan = (x => x.Year > 2020);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionGreaterThan.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionLessThanOrEqual = (x => x.Year <= 2020);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionLessThanOrEqual.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionGreaterThanOrEqual = (x => x.Year >= 2020);
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionGreaterThanOrEqual.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionToLower = (x => x.Name.ToLower() == "foo");
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionToLower.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionToLower = (x => !(x.Name.ToLower() == "foo"));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionToLower.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionToLower = (x => !(x.Name.ToLower() != "foo"));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionToLower.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionToUpper = (x => x.Name.ToUpper() == "FOO");
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionToUpper.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionSubString = (x => x.Name.Substring(0, 3) == "Fooooo");
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionSubString.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionStartsWith = (x => x.Name.StartsWith('F'));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionStartsWith.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionStartsWith = (x => !x.Name.StartsWith('F'));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionStartsWith.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
Expression <Func <SampleEntity, bool> > expressionEndsWith = (x => x.Name.EndsWith("o"));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionEndsWith.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
expressionEndsWith = (x => !x.Name.EndsWith("o"));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionEndsWith.Body, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
List <string> stringListItems = new List <string>()
{
"foo", "goo", "too"
};
Expression <Func <SampleEntity, bool> > expressionStringListContains = (x => stringListItems.Contains(x.Name));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionStringListContains, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
string[] stringArrayItems = new string[] { "foo", "goo", "too" };
Expression <Func <SampleEntity, bool> > expressionStringArrayContains = (x => stringArrayItems.Contains(x.Name));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionStringArrayContains, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
List <int> integerListItems = new List <int>()
{
1990, 2000, 2010, 2020
};
Expression <Func <SampleEntity, bool> > expressionIntegerListContains = (x => integerListItems.Contains(x.Year));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionIntegerListContains, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
int[] integerArrayItems = new int[] { 1990, 2000, 2010, 2020 };
Expression <Func <SampleEntity, bool> > expressionIntegerArrayContains = (x => integerArrayItems.Contains(x.Year));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionIntegerArrayContains, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
expressionResults.Clear();
integerArrayItems = new int[] { 1, 2, 3 };
expressionIntegerArrayContains = (x => !integerArrayItems.Contains(x.Year));
expressionResults = ExpressionUtil.GetWhereExpressions <SampleEntity>(expressionIntegerArrayContains, expressionResults);
rawText = expressionResults.ConvertToSqlWhereStatement();
Expression <Func <SampleEntity, object> > orderByExpression = (x => x.Name);
OrderByExpressionResult orderByExpressionResult = ExpressionUtil.GetOrderByExpression <SampleEntity>(orderByExpression);
rawText = new List <OrderByExpressionResult>()
{
orderByExpressionResult
}.ConvertToSqlOrderByStatement();
}
