public static string GetFieldLabel(this IDynamoCommonQuery q, string field)
{
if (!DynamoConfig.IsReservedWord(field))
{
return(field);
}
var alias = "#" + field.Substring(0, 2).ToUpper();
bool aliasExists = false;
foreach (var entry in q.ExpressionAttributeNames)
{
if (entry.Value == field)
{
return(entry.Key);
}
if (entry.Key == alias)
{
aliasExists = true;
}
}
if (aliasExists)
{
alias += q.ExpressionAttributeNames.Count;
}
q.ExpressionAttributeNames[alias] = field;
return(alias);
}
public virtual void AddConditions(IDynamoCommonQuery dynamoQ, IDataQuery q)
{
if (q.Conditions.Count == 0)
{
return;
}
var dbConditions = new List <DataConditionExpression>();
var args = new Dictionary <string, object>();
var sb = StringBuilderCache.Allocate();
var isMultipleWithOrTerm = q.Conditions.Any(x => x.Term == QueryTerm.Or) &&
q.Conditions.Count > 1;
foreach (var condition in q.Conditions)
{
var fmt = DynamoQueryConditions.GetExpressionFormat(condition.QueryCondition.Alias);
var multiFmt = DynamoQueryConditions.GetMultiExpressionFormat(condition.QueryCondition.Alias);
if (fmt == null && multiFmt == null && isMultipleWithOrTerm)
{
throw new NotSupportedException(
$"DynamoDB does not support {condition.QueryCondition.Alias} filter with multiple OR queries");
}
if (fmt == null && multiFmt == null)
{
continue;
}
dbConditions.Add(condition);
if (sb.Length > 0)
{
sb.Append(condition.Term == QueryTerm.Or ? " OR " : " AND ");
}
if (fmt != null)
{
var pId = "p" + args.Count;
args[pId] = condition.Value;
sb.Append(string.Format(fmt, dynamoQ.GetFieldLabel(condition.Field.Name), ":" + pId));
}
else
{
var multiExpr = GetMultiConditionExpression(dynamoQ, condition, multiFmt, args);
sb.Append(multiExpr);
}
}
var filter = StringBuilderCache.Retrieve(sb);
if (filter.Length > 0)
{
dynamoQ.AddFilter(filter, args);
}
q.Conditions.RemoveAll(dbConditions.Contains);
}
public static void SelectFields(this IDynamoCommonQuery q, IEnumerable <string> fields)
{
var fieldLabels = fields.Select(field => GetFieldLabel(q, field)).ToArray();
q.ProjectionExpression = fieldLabels.Length > 0
? string.Join(", ", fieldLabels)
: null;
}
public static void AddFilter(this IDynamoCommonQuery q, string filterExpression, Dictionary <string, object> args)
{
if (q.FilterExpression == null)
{
q.FilterExpression = filterExpression;
}
else
{
q.FilterExpression += " AND " + filterExpression;
}
q.AddArguments(args);
}
public virtual string GetMultiConditionExpression(IDynamoCommonQuery dynamoQ, DataConditionExpression condition, string multiFmt, Dictionary <string, object> args, string argPrefix = "p")
{
if (multiFmt == null)
{
return(null);
}
if (condition.QueryCondition.Alias == ConditionAlias.Between)
{
var values = ((IEnumerable)condition.Value).Map(x => x);
if (values.Count < 2)
{
throw new ArgumentException($"{condition.Field.Name} BETWEEN must have 2 values");
}
var pFrom = argPrefix + args.Count;
args[pFrom] = values[0];
var pTo = argPrefix + args.Count;
args[pTo] = values[1];
return(string.Format(multiFmt, dynamoQ.GetFieldLabel(condition.Field.Name), ":" + pFrom, ":" + pTo));
}
else
{
var values = (IEnumerable)condition.Value;
var sbIn = StringBuilderCache.Allocate();
foreach (var value in values)
{
if (sbIn.Length > 0)
{
sbIn.Append(",");
}
var pArg = argPrefix + args.Count;
args[pArg] = value;
sbIn.Append(":" + pArg);
}
return(string.Format(multiFmt,
dynamoQ.GetFieldLabel(condition.Field.Name),
StringBuilderCache.Retrieve(sbIn)));
}
}
internal static string GetFieldLabel(IDynamoCommonQuery q, string field)
{
if (!DynamoConfig.IsReservedWord(field))
return field;
var alias = "#" + field.Substring(0, 2).ToUpper();
bool aliasExists = false;
foreach (var entry in q.ExpressionAttributeNames)
{
if (entry.Value == field)
return entry.Key;
if (entry.Key == alias)
aliasExists = true;
}
if (aliasExists)
alias += q.ExpressionAttributeNames.Count;
q.ExpressionAttributeNames[alias] = field;
return alias;
}
