/// <inheritdoc />
public WhereExpression GenerateWhereCondition(Expression whereExpression)
{
Check.NotNull(whereExpression, nameof(whereExpression));
LinqParameters = new Parameters();
LinqStringBuilder = new StringBuilder();
MemberExpressionStack.Clear();
Visit(whereExpression);
return(new WhereExpression(LinqStringBuilder.ToString(), LinqParameters.GetParams()));
}
/// <summary>
/// Visits the member.
/// </summary>
/// <param name="expression">The expression.</param>
/// <exception cref="System.NotSupportedException">If the member type is not supported.</exception>
protected override Expression VisitMember(MemberExpression expression)
{
if (expression.Expression != null &&
(expression.Expression.NodeType == ExpressionType.Parameter ||
expression.Expression.NodeType == ExpressionType.Convert))
{
AppendMemberColumnName(expression);
return(expression);
}
MemberExpressionStack.Push(expression);
Expression result = base.VisitMember(expression);
if (PreviousMemberExpression == expression)
{
MemberExpressionStack.Pop();
}
return(result);
}
/// <summary>
/// Generates the SQL from expression.
/// </summary>
/// <param name="expression">The expression.</param>
/// <returns>SQL select command text.</returns>
public virtual QueryInfo GenerateSql(Expression expression)
{
Check.NotNull(expression, nameof(expression));
_wasAny = false;
_sqlBuilder = new StringBuilder();
_top = 0;
_topPosition = 0;
_skip = 0;
_columnsPosition = 0;
LinqParameters = new Parameters();
Orders.Clear();
MemberExpressionStack.Clear();
Visit(expression);
CheckSkip();
AddOrderBy();
AddAnyMethod();
AddLimitAndOffset();
return(new QueryInfo(SqlBuilder.ToString(), CreateQueryReader()));
}
/// <summary>
/// Returns value of constant expression <paramref name="expression"/>.
/// </summary>
/// <param name="expression">Expression.</param>
/// <returns>Value of the <paramref name="expression"/>.</returns>
protected object GetConstantExpressionValue(ConstantExpression expression)
{
object val = expression.Value;
MemberExpression prevNode;
while ((prevNode = PreviousMemberExpression) != null)
{
if (prevNode.Member is FieldInfo fi)
{
val = fi.GetValue(val);
}
else if (prevNode.Member is PropertyInfo pi)
{
val = pi.GetValue(val);
}
else
{
throw new NotSupportedException(
string.Format(Resources.Error_CannotGetValueOfConstantExpression, expression));
}
MemberExpressionStack.Pop();
}
return(val);
}
