public static DbExpression StripInvalidConvert(DbExpression exp)
{
DbConvertExpression convertExpression = exp as DbConvertExpression;
if (convertExpression == null)
return exp;
if (convertExpression.Type.IsEnum)
{
//(enumType)123
if (typeof(int) == convertExpression.Operand.Type)
return StripInvalidConvert(convertExpression.Operand);
DbConvertExpression newExp = new DbConvertExpression(typeof(int), convertExpression.Operand);
return StripInvalidConvert(newExp);
}
Type unType;
//(int?)123
if (Utils.IsNullable(convertExpression.Type, out unType))//可空类型转换
{
if (unType == convertExpression.Operand.Type)
return StripInvalidConvert(convertExpression.Operand);
DbConvertExpression newExp = new DbConvertExpression(unType, convertExpression.Operand);
return StripInvalidConvert(newExp);
}
//(int)enumTypeValue
if (exp.Type == typeof(int))
{
//(int)enumTypeValue
if (convertExpression.Operand.Type.IsEnum)
return StripInvalidConvert(convertExpression.Operand);
//(int)NullableEnumTypeValue
if (Utils.IsNullable(convertExpression.Operand.Type, out unType) && unType.IsEnum)
return StripInvalidConvert(convertExpression.Operand);
}
//float long double and so on
if (exp.Type.IsValueType)
{
//(long)NullableValue
if (Utils.IsNullable(convertExpression.Operand.Type, out unType) && unType == exp.Type)
return StripInvalidConvert(convertExpression.Operand);
}
if (convertExpression.Type == convertExpression.Operand.Type)
{
return StripInvalidConvert(convertExpression.Operand);
}
//如果是子类向父类转换
if (exp.Type.IsAssignableFrom(convertExpression.Operand.Type))
return StripInvalidConvert(convertExpression.Operand);
return convertExpression;
}
static void Method_ToString(DbMethodCallExpression exp, SqlGenerator generator)
{
if (exp.Method.Name != "ToString" && exp.Arguments.Count != 0)
{
throw UtilExceptions.NotSupportedMethod(exp.Method);
}
if (exp.Object.Type == UtilConstants.TypeOfString)
{
exp.Object.Accept(generator);
return;
}
if (!NumericTypes.ContainsKey(exp.Object.Type.GetUnderlyingType()))
{
throw UtilExceptions.NotSupportedMethod(exp.Method);
}
DbConvertExpression c = DbExpression.Convert(exp.Object, UtilConstants.TypeOfString);
c.Accept(generator);
}
public override DbExpression Visit(DbConvertExpression exp)
{
DbExpression stripedExp = DbExpressionExtension.StripInvalidConvert(exp);
if (stripedExp.NodeType != DbExpressionType.Convert)
{
EnsureDbExpressionReturnCSharpBoolean(stripedExp).Accept(this);
return exp;
}
exp = (DbConvertExpression)stripedExp;
if (exp.Type == UtilConstants.TypeOfString)
{
this._sqlBuilder.Append("TO_CHAR(");
exp.Operand.Accept(this);
this._sqlBuilder.Append(")");
return exp;
}
if (exp.Type == UtilConstants.TypeOfDateTime)
{
this._sqlBuilder.Append("TO_TIMESTAMP(");
exp.Operand.Accept(this);
this._sqlBuilder.Append(",'yyyy-mm-dd hh24:mi:ssxff')");
return exp;
}
string dbTypeString;
if (TryGetCastTargetDbTypeString(exp.Operand.Type, exp.Type, out dbTypeString, false))
{
this.BuildCastState(EnsureDbExpressionReturnCSharpBoolean(exp.Operand), dbTypeString);
}
else
EnsureDbExpressionReturnCSharpBoolean(exp.Operand).Accept(this);
return exp;
}
public override DbExpression Visit(DbConvertExpression exp)
{
DbExpression stripedExp = DbExpressionExtension.StripInvalidConvert(exp);
if (stripedExp.NodeType != DbExpressionType.Convert)
{
stripedExp.Accept(this);
return(exp);
}
exp = (DbConvertExpression)stripedExp;
string dbTypeString;
if (TryGetCastTargetDbTypeString(exp.Operand.Type, exp.Type, out dbTypeString, false))
{
this.BuildCastState(exp.Operand, dbTypeString);
}
else
{
Type targetType = ReflectionExtension.GetUnderlyingType(exp.Type);
if (targetType == PublicConstants.TypeOfDateTime)
{
/* DATETIME('2016-08-06 09:01:24') */
this.SqlBuilder.Append("DATETIME(");
exp.Operand.Accept(this);
this.SqlBuilder.Append(")");
}
else
{
exp.Operand.Accept(this);
}
}
return(exp);
}
public override object Visit(DbConvertExpression exp)
{
object operandValue = exp.Operand.Accept(this);
//(int)null
if (operandValue == null)
{
//(int)null
if (exp.Type.IsValueType && !exp.Type.IsNullable())
{
throw new NullReferenceException();
}
return(null);
}
Type operandValueType = operandValue.GetType();
if (exp.Type == operandValueType || exp.Type.IsAssignableFrom(operandValueType))
{
return(operandValue);
}
Type underlyingType;
if (exp.Type.IsNullable(out underlyingType))
{
//(int?)int
if (underlyingType == operandValueType)
{
var constructor = exp.Type.GetConstructor(new Type[] { operandValueType });
var val = constructor.Invoke(new object[] { operandValue });
return(val);
}
else
{
//如果不等，则诸如：(long?)int / (long?)int? --> (long?)((long)int) / (long?)((long)int?)
var c = DbExpression.Convert(DbExpression.Constant(operandValue), underlyingType);
var cc = DbExpression.Convert(c, exp.Type);
return(this.Visit(cc));
}
}
//(int)int?
if (operandValueType.IsNullable(out underlyingType))
{
if (underlyingType == exp.Type)
{
var pro = operandValueType.GetProperty("Value");
var val = pro.GetValue(operandValue, null);
return(val);
}
else
{
//如果不等，则诸如：(long)int? --> (long)((long)int)
var c = DbExpression.Convert(DbExpression.Constant(operandValue), underlyingType);
var cc = DbExpression.Convert(c, exp.Type);
return(this.Visit(cc));
}
}
if (exp.Type.IsEnum)
{
return(Enum.ToObject(exp.Type, operandValue));
}
//(long)int
if (operandValue is IConvertible)
{
return(Convert.ChangeType(operandValue, exp.Type));
}
throw new NotSupportedException(string.Format("Does not support the type '{0}' converted to type '{1}'.", operandValueType.FullName, exp.Type.FullName));
}
public override DbExpression Visit(DbConvertExpression exp)
{
return(exp);
}
/// <summary>
/// 尝试将 exp 转换成 DbParameterExpression。
/// </summary>
/// <param name="exp"></param>
/// <returns></returns>
public static DbExpression ParseDbExpression(this DbExpression exp)
{
DbExpression stripedExp = DbExpressionHelper.StripInvalidConvert(exp);
DbExpression tempExp = stripedExp;
List<DbConvertExpression> cList = null;
while (tempExp.NodeType == DbExpressionType.Convert)
{
if (cList == null)
cList = new List<DbConvertExpression>();
DbConvertExpression c = (DbConvertExpression)tempExp;
cList.Add(c);
tempExp = c.Operand;
}
if (tempExp.NodeType == DbExpressionType.Constant || tempExp.NodeType == DbExpressionType.Parameter)
return stripedExp;
if (tempExp.NodeType == DbExpressionType.MemberAccess)
{
DbParameterExpression val;
if (DbExpressionExtensions.TryParseToParameterExpression((DbMemberExpression)tempExp, out val))
{
if (cList != null)
{
if (val.Value == DBNull.Value)//如果是 null，则不需要 Convert 了，在数据库里没意义
return val;
DbConvertExpression c = null;
for (int i = cList.Count - 1; i > -1; i--)
{
DbConvertExpression item = cList[i];
c = new DbConvertExpression(item.Type, val);
}
return c;
}
return val;
}
}
return stripedExp;
}
public override DbExpression Visit(DbConvertExpression exp)
{
return(exp.Accept(this._generator));
}
public abstract T Visit(DbConvertExpression exp);
public static DbExpression StripInvalidConvert(this DbExpression exp)
{
if (exp.NodeType != DbExpressionType.Convert)
{
return(exp);
}
DbConvertExpression convertExpression = (DbConvertExpression)exp;
if (convertExpression.Type.IsEnum())
{
//(enumType)123
if (typeof(int) == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
DbConvertExpression newExp = new DbConvertExpression(typeof(int), convertExpression.Operand);
return(StripInvalidConvert(newExp));
}
Type underlyingType;
//(int?)123
if (ReflectionExtension.IsNullable(convertExpression.Type, out underlyingType))//可空类型转换
{
if (underlyingType == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
DbConvertExpression newExp = new DbConvertExpression(underlyingType, convertExpression.Operand);
return(StripInvalidConvert(newExp));
}
//(int)enumTypeValue
if (exp.Type == typeof(int))
{
//(int)enumTypeValue
if (convertExpression.Operand.Type.IsEnum())
{
return(StripInvalidConvert(convertExpression.Operand));
}
//(int)NullableEnumTypeValue
if (ReflectionExtension.IsNullable(convertExpression.Operand.Type, out underlyingType) && underlyingType.IsEnum())
{
return(StripInvalidConvert(convertExpression.Operand));
}
}
//float long double and so on
if (exp.Type.IsValueType())
{
//(long)NullableValue
if (ReflectionExtension.IsNullable(convertExpression.Operand.Type, out underlyingType) && underlyingType == exp.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
}
if (convertExpression.Type == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
//如果是子类向父类转换
if (exp.Type.IsAssignableFrom(convertExpression.Operand.Type))
{
return(StripInvalidConvert(convertExpression.Operand));
}
return(convertExpression);
}
public static DbExpression StripInvalidConvert(DbExpression exp)
{
DbConvertExpression convertExpression = exp as DbConvertExpression;
if (convertExpression == null)
{
return(exp);
}
if (convertExpression.Type.IsEnum)
{
//(enumType)123
if (typeof(int) == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
DbConvertExpression newExp = new DbConvertExpression(typeof(int), convertExpression.Operand);
return(StripInvalidConvert(newExp));
}
Type unType;
//(int?)123
if (Utils.IsNullable(convertExpression.Type, out unType))//可空类型转换
{
if (unType == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
DbConvertExpression newExp = new DbConvertExpression(unType, convertExpression.Operand);
return(StripInvalidConvert(newExp));
}
//(int)enumTypeValue
if (exp.Type == typeof(int))
{
//(int)enumTypeValue
if (convertExpression.Operand.Type.IsEnum)
{
return(StripInvalidConvert(convertExpression.Operand));
}
//(int)NullableEnumTypeValue
if (Utils.IsNullable(convertExpression.Operand.Type, out unType) && unType.IsEnum)
{
return(StripInvalidConvert(convertExpression.Operand));
}
}
//float long double and so on
if (exp.Type.IsValueType)
{
//(long)NullableValue
if (Utils.IsNullable(convertExpression.Operand.Type, out unType) && unType == exp.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
}
if (convertExpression.Type == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
//如果是子类向父类转换
if (exp.Type.IsAssignableFrom(convertExpression.Operand.Type))
{
return(StripInvalidConvert(convertExpression.Operand));
}
return(convertExpression);
}
public static DbExpression StripInvalidConvert(this DbExpression exp)
{
if (exp.NodeType != DbExpressionType.Convert)
{
return(exp);
}
DbConvertExpression convertExpression = (DbConvertExpression)exp;
if (convertExpression.Type == convertExpression.Operand.Type)
{
return(StripInvalidConvert(convertExpression.Operand));
}
//(enumType)1
if (convertExpression.Type.IsEnum)
{
Type enumUnderlyingType = Enum.GetUnderlyingType(convertExpression.Type);
if (enumUnderlyingType == convertExpression.Operand.Type)
{
//(enumType)1 --> 1
return(StripInvalidConvert(convertExpression.Operand));
}
//(enumType)1 --> (Int16/Int32/Int64)1
DbConvertExpression newExp = new DbConvertExpression(enumUnderlyingType, convertExpression.Operand);
return(StripInvalidConvert(newExp));
}
Type underlyingType;
//(Nullable<T>)1
if (convertExpression.Type.IsNullable(out underlyingType))//可空类型转换
{
if (underlyingType == convertExpression.Operand.Type)
{
//T == convertExpression.Operand.Type
//(Nullable<T>)1 --> 1
return(StripInvalidConvert(convertExpression.Operand));
}
//(Nullable<T>)1 --> (T)1
DbConvertExpression newExp = new DbConvertExpression(underlyingType, convertExpression.Operand);
return(StripInvalidConvert(newExp));
}
if (!exp.Type.IsEnum)
{
//(Int16/Int32/Int64)TEnum
if (convertExpression.Operand.Type.IsEnum)
{
//(Int16/Int32/Int64)TEnum --> TEnum
return(StripInvalidConvert(convertExpression.Operand));
}
//(Int16/Int32/Int64)Nullable<TEnum>
if (convertExpression.Operand.Type.IsNullable(out underlyingType) && underlyingType.IsEnum)
{
//(Int16/Int32/Int64)Nullable<TEnum> --> TEnum
return(StripInvalidConvert(convertExpression.Operand));
}
}
//float long double and so on
if (exp.Type.IsValueType)
{
if (convertExpression.Operand.Type.IsNullable(out underlyingType) && underlyingType == exp.Type)
{
//(T)Nullable<T> --> T
return(StripInvalidConvert(convertExpression.Operand));
}
}
//如果是子类向父类转换
if (exp.Type.IsAssignableFrom(convertExpression.Operand.Type))
{
return(StripInvalidConvert(convertExpression.Operand));
}
return(convertExpression);
}
public override bool Visit(DbConvertExpression exp)
{
return(this.VisitCore(exp.Operand));
}
public static bool ExpressionEquals(DbConvertExpression exp1, DbConvertExpression exp2)
{
if (exp1.Type != exp2.Type)
return false;
return EqualsCompare(exp1.Operand, exp2.Operand);
}
public override DbExpression Visit(DbConvertExpression exp)
{
exp = DbExpression.Convert(exp.Operand.Accept(this), exp.Type);
return(exp);
}