public virtual async Task Functions_CountDistinct()
{
using (var tempTable = await DataTestHelpers.CreateAutoIncrementTable(DataProvider))
{
await DataProvider.ExecuteNonQueryAsync(QueryExpression.Insert(
tempTable.TableName,
new[] { "Data" },
new object[] { 10 },
new object[] { 10 },
new object[] { 15 },
new object[] { 20 }
));
using (var queryResult = await DataProvider.ExecuteReaderAsync(
QueryExpression.Select(
new[] { QueryExpression.CountFunction(
QueryExpression.Distinct(QueryExpression.Column("Data"))
) },
from: QueryExpression.Table(tempTable.TableName)
)))
{
Assert.IsTrue(queryResult.HasRows);
Assert.IsTrue(await queryResult.ReadAsync());
Assert.AreEqual(3, queryResult.GetInt32(0));
}
}
}
public void Can_Write_Select_With_Distinct_Count()
{
var queryExpression = QueryExpression.Select(
new[] { QueryExpression.Count(
QueryExpression.Distinct(QueryExpression.Column("Id"))
) }
);
var sql = TestHelpers.ConvertToSql(queryExpression);
Assert.AreEqual("SELECT COUNT(DISTINCT [Id]);", sql);
}