private ExpressionAttribute GetBestMatchingExpression(IEnumerable <ExpressionAttribute> expressions,
ref string dialectServerType, ref string dialectTypeName)
{
if (!expressions.Any(x => !string.IsNullOrEmpty(x.Dialect)))
{
return(expressions.FirstOrDefault());
}
if (dialectTypeName == null)
{
ISqlDialect dialect = null;
if (!string.IsNullOrEmpty(connectionKey))
{
var csi = SqlConnections.TryGetConnectionString(connectionKey);
if (csi != null)
{
dialect = csi.Dialect;
}
}
dialect = dialect ?? SqlSettings.DefaultDialect;
dialectServerType = dialect.ServerType;
dialectTypeName = dialect.GetType().Name;
}
var st = dialectServerType;
var tn = dialectTypeName;
Func <string, bool> isMatch = s =>
{
return(st.StartsWith(s, StringComparison.OrdinalIgnoreCase) ||
tn.StartsWith(s, StringComparison.OrdinalIgnoreCase));
};
Dictionary <ExpressionAttribute, int> weight = null;
var bestMatch = expressions.Where(x =>
{
if (string.IsNullOrEmpty(x.Dialect))
{
return(true);
}
if (x.Dialect.IndexOf(',') < 0)
{
return(isMatch(x.Dialect));
}
var best = x.Dialect.Split(comma, StringSplitOptions.RemoveEmptyEntries)
.Select(z => z.Trim())
.Where(z => isMatch(z))
.OrderByDescending(z => z.Length)
.FirstOrDefault();
if (best != null)
{
if (weight == null)
{
weight = new Dictionary <ExpressionAttribute, int>();
}
weight[x] = best.Length;
return(true);
}
return(false);
})
.OrderByDescending(x =>
{
if (string.IsNullOrEmpty(x.Dialect))
{
return(0);
}
int w;
if (weight != null && weight.TryGetValue(x, out w))
{
return(w);
}
return(x.Dialect.Length);
})
.FirstOrDefault();
return(bestMatch);
}
public static IDbConnection NewConnection(RowFieldsBase fields)
{
return(SqlConnections.NewByKey(fields.connectionKey));
}