public static string GetQueryFromExpression(ITranslator translator, Expression clause, Parameters parameters)
{
var members = GetMemberExpressions(translator, clause);
if (!members.Any())
{
return(string.Empty);
}
var enumerator = members.GetEnumerator();
return(GetString(translator, enumerator, parameters));
}
public static string GetString(ITranslator translator, IEnumerator <Expression> iterator, Parameters parameters)
{
if (!iterator.MoveNext())
{
return(string.Empty);
}
var expression = iterator.Current;
var binaryExpression = expression as BinaryExpression;
if (binaryExpression != null)
{
return(BinaryExpressionString(translator, iterator, binaryExpression, parameters));
}
var memberExpression = expression as MemberExpression;
if (memberExpression != null)
{
return(MemberExpressionString(translator, memberExpression, parameters));
}
var constantExpression = expression as ConstantExpression;
if (constantExpression != null)
{
return(ConstantExpressionString(translator, constantExpression, parameters));
}
var methodCallExpression = expression as MethodCallExpression;
if (methodCallExpression != null)
{
string constantValue;
if (GetSqlExtensionMethodCallConstant(translator, methodCallExpression, parameters, out constantValue))
{
return(constantValue);
}
}
return(string.Empty);
}
public static bool GetSqlExtensionMethodCallConstant(ITranslator translator, MethodCallExpression methodExpression, Parameters parameters, out string concat)
{
if (methodExpression.Method.Name == "Min" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("MIN(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "Max" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("MAX(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "Sum" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("SUM(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "As" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
var aliasFormat = translator.GetAliasFormat();
var alias = string.Format(aliasFormat,
Convert.ToString(methodExpression.Arguments[1]).Replace("\"", "").Replace("'", ""));
concat = string.Concat(GetStringForExpression(translator, methodExpression.Arguments[0], parameters), " AS ", alias);
return(true);
}
if (methodExpression.Method.Name == "Between" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), " BETWEEN ",
GetStringForExpression(translator, methodExpression.Arguments[1], parameters), " AND ",
GetStringForExpression(translator, methodExpression.Arguments[2], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "In" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), " IN (",
GetStringForExpression(translator, methodExpression.Arguments[1], parameters), "))");
return(true);
}
if (methodExpression.Method.Name == "Like" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), " LIKE ",
GetStringForExpression(translator, methodExpression.Arguments[1], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "TrimSql" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("LTRIM(RTRIM(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), "))");
return(true);
}
if (methodExpression.Method.Name == "Length" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
var lengthName = translator.GetLengthFunctionName();
concat = string.Concat(lengthName, "(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "Upper" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("UPPER(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "Lower" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("LOWER(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "IsNull" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
var isNullName = translator.GetIsNullFunctionName();
concat = string.Concat(isNullName, "(",
GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ",",
GetStringForExpression(translator, methodExpression.Arguments[1], parameters), ")");
return(true);
}
if (methodExpression.Method.Name == "Cast" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
var returnDbType = TableDefinition.GetTypeForProperty(methodExpression.Method.ReturnType);
concat = string.Concat("CAST(",
GetStringForExpression(translator, methodExpression.Arguments[0], parameters), " AS ",
translator.GetTextFor(new FieldDefinition {
Type = returnDbType
}, true), ")");
return(true);
}
if (methodExpression.Method.Name == "Average" && methodExpression.Method.ReflectedType.Name == "SqlExtensions")
{
concat = string.Concat("AVG(", GetStringForExpression(translator, methodExpression.Arguments[0], parameters), ")");
return(true);
}
concat = "";
return(false);
}
private static string GetStringForExpression(ITranslator translator, Expression expression, Parameters parameters)
{
var memberExpression = expression as MemberExpression;
if (memberExpression != null)
{
var constantExpression = memberExpression.Expression as ConstantExpression;
if (constantExpression != null)
{
var container = constantExpression.Value;
var member = memberExpression.Member;
var fieldInfo = member as FieldInfo;
if (fieldInfo != null)
{
var value = fieldInfo.GetValue(container);
return(GetStringForExpression(translator, Expression.Constant(value), parameters));
}
var propertyInfo = member as PropertyInfo;
if (propertyInfo != null)
{
var value = propertyInfo.GetValue(container, null);
return(GetStringForExpression(translator, Expression.Constant(value), parameters));
}
}
var tableDefinition = new TableDefinition(memberExpression.Member.DeclaringType);
return(string.Concat(tableDefinition.Name, ".", memberExpression.Member.Name));
}
var constExpr = expression as ConstantExpression;
if (constExpr != null)
{
var value = GetValueFrom(translator, constExpr.Type, constExpr.Value);
var key = parameters.Add(translator, value);
return(key);
}
var methodExpression = expression as MethodCallExpression;
if (methodExpression != null)
{
string concat;
if (GetSqlExtensionMethodCallConstant(translator, methodExpression, parameters, out concat))
{
return(concat);
}
}
var newArrayExpression = expression as NewArrayExpression;
if (newArrayExpression != null)
{
return(string.Join(",", newArrayExpression.Expressions.Select(ex => GetStringForExpression(translator, ex, parameters))));
}
return(string.Empty);
}
public static string ConstantExpressionString(ITranslator translator, ConstantExpression constantExpression, Parameters parameters)
{
var value = GetValueFrom(translator, constantExpression.Type, constantExpression.Value);
return(parameters.Add(translator, value));
}
public static string BinaryExpressionString(ITranslator translator, IEnumerator <Expression> iterator, BinaryExpression binaryExpression, Parameters parameters)
{
var format = translator.GetFormatFor(binaryExpression.NodeType);
var left = string.Empty;
var right = string.Empty;
if (iterator.MoveNext())
{
left = GetQueryFromExpression(translator, iterator.Current, parameters);
}
if (iterator.MoveNext())
{
right = GetQueryFromExpression(translator, iterator.Current, parameters);
}
return(string.Format(format, left, right));
}
public static string MemberExpressionString(ITranslator translator, MemberExpression memberExpression, Parameters parameters)
{
if (memberExpression.Expression is ConstantExpression)
{
return(GetStringForExpression(translator, memberExpression, parameters));
}
var tableDefinition = new TableDefinition(memberExpression.Member.DeclaringType);
var member = (PropertyInfo)memberExpression.Member;
var field = tableDefinition.Fields.FirstOrDefault(f => f.PropertyInfo.Name == member.Name);
if (field == null)
{
return(string.Concat(tableDefinition.Name, ".", member.Name));
}
return(string.Concat(tableDefinition.Name, ".", field));
}