internal override SqlExpression VisitUnaryOperator(SqlUnary uo)
{
base.VisitUnaryOperator(uo);
if (uo.NodeType != SqlNodeType.Convert && uo.Operand != null && uo.Operand.SqlType != null)
{
uo.SetSqlType(this.typeProvider.PredictTypeForUnary(uo.NodeType, uo.Operand.SqlType));
}
return(uo);
}
internal override SqlExpression VisitUnaryOperator(SqlUnary uo)
{
uo.Operand = this.VisitExpression(uo.Operand);
if (uo.NodeType != SqlNodeType.Convert)
{
return(uo);
}
ProviderType oldSqlType = uo.Operand.SqlType;
ProviderType newSqlType = uo.SqlType;
Type oldClrType = TypeSystem.GetNonNullableType(uo.Operand.ClrType);
Type newClrType = TypeSystem.GetNonNullableType(uo.ClrType);
if (newClrType == typeof(char))
{
if (oldClrType == typeof(bool))
{
throw Error.ConvertToCharFromBoolNotSupported();
}
if (oldSqlType.IsNumeric)
{
// numeric --> char
return(sql.FunctionCall(uo.ClrType, "NCHAR", new SqlExpression[] { uo.Operand }, uo.SourceExpression));
}
if (StringConversionIsSafe(oldSqlType, newSqlType))
{
if (StringConversionIsNeeded(oldSqlType, newSqlType))
{
// set the new size to the (potentially smaller) oldSqlType.Size
uo.SetSqlType(sql.TypeProvider.From(uo.ClrType, oldSqlType.HasSizeOrIsLarge ? oldSqlType.Size : (int?)null));
}
}
else
{
throw Error.UnsafeStringConversion(oldSqlType.ToQueryString(), newSqlType.ToQueryString());
}
}
else if (oldClrType == typeof(char) && (oldSqlType.IsChar || oldSqlType.IsString) && newSqlType.IsNumeric)
{
// char --> int
return(sql.FunctionCall(newClrType, sql.TypeProvider.From(typeof(int)), "UNICODE", new SqlExpression[] { uo.Operand }, uo.SourceExpression));
}
else if (newClrType == typeof(string))
{
if (oldClrType == typeof(double))
{
// use longer format if it was a double in the CLR expression
return(ConvertDoubleToString(uo.Operand, uo.ClrType));
}
else if (oldClrType == typeof(bool))
{
// use 'true' or 'false' if it was a bool in the CLR expression
return(ConvertBitToString(uo.Operand, uo.ClrType));
}
else if (StringConversionIsSafe(oldSqlType, newSqlType))
{
if (StringConversionIsNeeded(oldSqlType, newSqlType))
{
// set the new size to the (potentially smaller) oldSqlType.Size
uo.SetSqlType(sql.TypeProvider.From(uo.ClrType, oldSqlType.HasSizeOrIsLarge ? oldSqlType.Size : (int?)null));
}
}
else
{
throw Error.UnsafeStringConversion(oldSqlType.ToQueryString(), newSqlType.ToQueryString());
}
}
return(uo);
}