private static async Task <bool> CheckIsEmail(DConnection conn, ExplorerContext ctx)
{
var emailCheck = await conn.Exec(
new TextColumnTrim(ctx.Table, ctx.Column, TextColumnTrimType.Both, Constants.EmailAddressChars));
return(emailCheck.Rows.All(r => r.IsNull || (!r.IsSuppressed && r.Value == "@")));
}
/// <summary>
/// Finds common substrings for each position in the texts of the specified column.
/// It uses a batch approach to query for several positions (specified using SubstringQueryColumnCount)
/// using a single query.
/// </summary>
private static async Task <SubstringsData> ExploreSubstrings(
DConnection conn,
ExplorerContext ctx,
int substringQueryColumnCount,
params int[] substringLengths)
{
var substrings = new SubstringsData();
foreach (var length in substringLengths)
{
var hasRows = true;
for (var pos = 0; hasRows; pos += substringQueryColumnCount)
{
var query = new TextColumnSubstring(ctx.Table, ctx.Column, pos, length, substringQueryColumnCount);
var sstrResult = await conn.Exec(query);
hasRows = false;
foreach (var row in sstrResult.Rows)
{
if (row.HasValue)
{
hasRows = true;
substrings.Add(pos + row.Index, row.Value, row.Count);
}
}
}
}
return(substrings);
}
protected override async Task <Result> Explore()
{
var isolators = await conn.Exec(new IsolatorQuery(ctx.Table));
var isIsolatorColumn = isolators.Rows.First(r => r.Item1 == ctx.Column).Item2;
return(new Result(ctx.Column, isIsolatorColumn));
}
private static async Task <SubstringWithCountList> ExploreEmailTopLevelDomains(DConnection conn, ExplorerContext ctx)
{
var suffixes = await conn.Exec(new TextColumnSuffix(ctx.Table, ctx.Column, 3, 7));
return(SubstringWithCountList.FromValueWithCountEnum(
suffixes.Rows
.Where(r => r.HasValue && r.Value.StartsWith(".", StringComparison.InvariantCulture))));
}
private static async Task <SubstringWithCountList> ExploreEmailDomains(DConnection conn, ExplorerContext ctx)
{
var domains = await conn.Exec(new TextColumnTrim(
ctx.Table, ctx.Column, TextColumnTrimType.Leading, Constants.EmailAddressChars));
return(SubstringWithCountList.FromValueWithCountEnum(
domains.Rows
.Where(r => r.HasValue && r.Value.StartsWith("@", StringComparison.InvariantCulture))));
}
protected override async Task <Result> Explore()
{
var queryResult = await conn.Exec(
new CyclicalDatetimes(ctx.Table, ctx.Column, ctx.ColumnType));
var groupings = await Task.Run(() => ProcessCyclicalBuckets(queryResult.Rows));
return(new Result(
groupings.Select(g => g.Item1),
groupings.Select(g => g.Item2)));
}
protected override async Task <SimpleStats <T> .Result> Explore()
{
var statsQ = await conn.Exec(new BasicColumnStats <T>(ctx.Table, ctx.Column));
return(new Result(statsQ.Rows.Single()));
}