protected override SqlGenerate Where(MemberExpression expression, SqlGenerate sqlGenerate)
{
if (expression.Expression != null)
{
if (expression.Member.DeclaringType.IsNullableType())
{
if (expression.Member.Name == "Value") //Can't use C# 6 yet: nameof(Nullable<bool>.Value)
{
SqlExpressionProvider.Where(expression.Expression, sqlGenerate);
return(sqlGenerate);
}
if (expression.Member.Name == "HasValue")
{
var doesNotEqualNull = Expression.MakeBinary(ExpressionType.NotEqual, expression.Expression, Expression.Constant(null));
SqlExpressionProvider.Where(doesNotEqualNull, sqlGenerate);
return(sqlGenerate);
}
throw new ArgumentException($"Expression '{expression}' accesses unsupported property '{expression.Member}' of Nullable<T>");
}
if (expression.IsParameterOrConvertAccess())
{
sqlGenerate += $" {expression.Member.Name.ParamSql(sqlGenerate)}";
return(sqlGenerate);
}
}
var val = SqlExpressionCompiler.Evaluate(expression);
sqlGenerate.AddDbParameter(val);
return(sqlGenerate);
}
/// <summary>
/// 获取Value
/// </summary>
/// <param name="binding"></param>
/// <returns></returns>
public static object GetValue(this MemberBinding binding)
{
switch (binding.BindingType)
{
case MemberBindingType.Assignment:
var assign = (MemberAssignment)binding;
if (assign.Expression is ConstantExpression constant)
{
return(constant.Value);
}
try
{
return(SqlExpressionCompiler.Evaluate(assign.Expression));
}
catch (Exception ex)
{
var member = Expression.Convert(assign.Expression, typeof(object));
var lambda = Expression.Lambda <Func <object> >(member);
var getter = lambda.Compile();
return(getter());
}
}
return(null);
}
protected override SqlGenerate In(MemberExpression expression, SqlGenerate sqlGenerate)
{
var result = SqlExpressionCompiler.Evaluate(expression);
var inArgs = (result as IEnumerable).Flatten();
sqlGenerate.AddDbParameter(inArgs);
return(sqlGenerate);
}
private static void StartsWith(MethodCallExpression expression, SqlGenerate sqlGenerate)
{
SqlExpressionProvider.Where(expression.Object, sqlGenerate);
SqlExpressionProvider.Where(expression.Arguments[0], sqlGenerate);
sqlGenerate += " like ";
var val = SqlExpressionCompiler.Evaluate(expression.Arguments[0]);
sqlGenerate.AddDbParameter($"{val}%");
}
protected override SqlGenerate In(NewArrayExpression expression, SqlGenerate sqlGenerate)
{
var list = new List <object>();
foreach (var expressionItem in expression.Expressions)
{
var obj = SqlExpressionCompiler.Evaluate(expressionItem);
list.Add(obj);
}
sqlGenerate.AddDbParameter(list);
return(sqlGenerate);
}
protected override SqlGenerate In(ListInitExpression expression, SqlGenerate sqlGenerate)
{
var list = new List <object>();
foreach (var elementInit in expression.Initializers)
{
foreach (var expre in elementInit.Arguments)
{
var obj = SqlExpressionCompiler.Evaluate(expre);
list.Add(obj);
}
}
sqlGenerate.AddDbParameter(list);
return(sqlGenerate);
}
private static void Format(MethodCallExpression expression, SqlGenerate sqlGenerate)
{
var formatString = SqlExpressionCompiler.Evaluate(expression.Arguments[0]);
var formatArgs = new List <string>();
var args = expression.Arguments;
if (args.Count > 1)
{
for (int i = 1; i < args.Count; i++)
{
var val = SqlExpressionCompiler.Evaluate(expression.Arguments[i]);
formatArgs.Add(val?.ToString());
}
}
sqlGenerate += string.Format(formatString.ToString(), formatArgs.ToArray());
}
protected override SqlGenerate Select(MemberExpression expression, SqlGenerate sqlGenerate)
{
if (IsEnumerable(expression))
{
var result = SqlExpressionCompiler.Evaluate(expression);
var fields = (result as IEnumerable).Flatten();
if (fields?.Count > 0)
{
sqlGenerate.SelectFields.AddRange(fields.Select(field => field.ToString().ParamSql(sqlGenerate)));
}
return(sqlGenerate);
}
sqlGenerate.SelectFields.Add(expression.Member.Name.ParamSql(sqlGenerate));
return(sqlGenerate);
}
protected override SqlGenerate Update(MemberExpression expression, SqlGenerate sqlGenerate)
{
var obj = SqlExpressionCompiler.Evaluate(expression);
if (obj == null)
{
throw new ArgumentException($"Expression '{expression}' accesses unsupported property '{expression.Member}' of Nullable<T>");
}
if (obj.GetType().IsValueType)
{
throw new ArgumentException($"Expression '{expression}' accesses unsupported valuetype");
}
if (obj.GetType() == typeof(string))
{
sqlGenerate += obj.ToString();
}
else if (obj is IDictionary dictionary)
{
foreach (string key in dictionary.Keys)
{
sqlGenerate += $"{key.ParamSql(sqlGenerate)} = ";
sqlGenerate.AddDbParameter(dictionary[key]);
sqlGenerate += ",";
}
}
else
{
var pis = obj.GetType().GetProperties();
foreach (var p in pis)
{
sqlGenerate += $"{p.Name.ParamSql(sqlGenerate)} = ";
sqlGenerate.AddDbParameter(p.GetValue(obj));
sqlGenerate += ",";
}
}
if (sqlGenerate[sqlGenerate.Length - 1] == ',')
{
sqlGenerate.Sql.Remove(sqlGenerate.Length - 1, 1);
}
return(sqlGenerate);
}
protected override SqlGenerate Update(NewExpression expression, SqlGenerate sqlGenerate)
{
for (int i = 0; i < expression.Members.Count; i++)
{
var m = expression.Members[i];
sqlGenerate += $"{m.Name.ParamSql(sqlGenerate)} = ";
var val = SqlExpressionCompiler.Evaluate(expression.Arguments[i]);
sqlGenerate.AddDbParameter(val);
sqlGenerate += ",";
}
if (sqlGenerate[sqlGenerate.Length - 1] == ',')
{
sqlGenerate.Sql.Remove(sqlGenerate.Length - 1, 1);
}
return(sqlGenerate);
}
/// <summary>
/// 获取Fields
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="expr"></param>
/// <returns></returns>
public static string[] GetFieldNames <T>(this Expression <Func <T, object> > expr)
{
if (expr == null)
{
return(null);
}
if (expr.Body is MemberExpression member)
{
if (member.Member.DeclaringType.IsAssignableFrom(typeof(T)))
{
return new[] { member.Member.Name }
}
;
var array = SqlExpressionCompiler.Evaluate(member);
if (array is IEnumerable <string> strEnum)
{
return(strEnum.ToArray());
}
}
if (expr.Body is NewExpression newExpr)
{
return(newExpr.Arguments.OfType <MemberExpression>().Select(x => x.Member.Name).ToArray());
}
if (expr.Body is MemberInitExpression init)
{
return(init.Bindings.Select(x => x.Member.Name).ToArray());
}
if (expr.Body is UnaryExpression unary)
{
member = unary.Operand as MemberExpression;
if (member != null)
{
return new[] { member.Member.Name }
}
;
}
throw new ArgumentException("Invalid Fields List Expression: " + expr);
}
private static void Contains(MethodCallExpression expression, SqlGenerate sqlGenerate)
{
if (IsStaticArrayMethod(expression))
{
DoStaticArrayMethodCall(expression, sqlGenerate);
return;
}
if (IsEnumerableMethod(expression))
{
DoEnumerableMethodCall(expression, sqlGenerate);
return;
}
SqlExpressionProvider.Where(expression.Object, sqlGenerate);
sqlGenerate += " like ";
var val = SqlExpressionCompiler.Evaluate(expression.Arguments[0]);
sqlGenerate.AddDbParameter($"%{val}%");
}
private static object ResolveMember(MemberExpression expression)
{
if (expression.Expression != null)
{
if (expression.Member.DeclaringType.IsNullableType())
{
return(null);
}
if (expression.IsParameterOrConvertAccess())
{
return(expression.Member.Name);
}
}
var val = SqlExpressionCompiler.Evaluate(expression);
return(val);
}
protected override SqlGenerate Select(ListInitExpression expression, SqlGenerate sqlGenerate)
{
foreach (var elementInit in expression.Initializers)
{
foreach (var expre in elementInit.Arguments)
{
var obj = SqlExpressionCompiler.Evaluate(expre);
if (obj == null)
{
continue;
}
var fieldName = obj.ToString();
if (string.IsNullOrEmpty(fieldName))
{
continue;
}
sqlGenerate.SelectFields.Add(fieldName.ParamSql(sqlGenerate));
}
}
return(sqlGenerate);
}
