/// <summary>
/// Gets the current rows from the table. Since this is accomplished with a trigger table its just a small querie.
/// </summary>
/// <param name="table">The table to get the current rows from.</param>
/// <returns>Returns the number of rows in the given table</returns>
public override int GetCurrentRowsFromTable(Table table)
{
try
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
sqb.Select().AddValue("rowCount").From().AddValue(table.TableName + "_count").Where().AddValue("id").Equal().AddValue("1");
List <List <object> > result = ReadQuery(sqb.ToString(),
new List <KeyValuePair <int, Type> >()
{
new KeyValuePair <int, Type>(0, typeof(int))
});
if (result == null)
{
return(0);
}
else
{
return((int)result[0][0]);
}
}
catch (Exception)
{
throw;
}
}
/// <summary>
/// Gets the current rows from the table. There are no triggers in access so i had to do it with the count method.
/// </summary>
/// <param name="table">The table to get the current rows from.</param>
/// <returns>Returns the number of rows in the given table</returns>
public override int GetCurrentRowsFromTable(Table table)
{
try
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
string columnName = table.Columns.First().Key;
sqb.Select().AddValue("Count(" + columnName + ")").From().AddValue(table.TableName);
List <List <object> > result = ReadQuery(sqb.ToString(),
new List <KeyValuePair <int, Type> >()
{
new KeyValuePair <int, Type>(0, typeof(int))
});
if (result == null)
{
return(0);
}
else
{
return((int)result[0][0]);
}
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// Get's the last n rows from the specified table.
/// <para/>
/// SQL query Example:<para/>
/// SELECT * FROM table ORDER BY id DESC LIMIT 100
/// </summary>
/// <param name="rows">number of the rows to display.</param>
/// <param name="table">The table to get the values from.</param>
/// <returns></returns>
public override List <List <object> > GetLastNRowsFromTable(Table table, int rows)
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
sqb.Select().ALL().From().AddValue(table.TableName).OrderBY().AddValue(table.Columns.First().Key).Desc().Limit().AddValue(rows.ToString());
List <List <object> > results = ReadQuery(sqb.ToString(), GenerateOutputValuesFromTable(table));
return(results);
}
/// <summary>
/// Deletes the last n rows of the given table.
/// </summary>
/// <param name="table">The table to delete the last n data from.</param>
/// <param name="rows">The amount of data to delete.</param>
public override void DeleteLastNRows(Table table, int rows)
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
string columnName = table.Columns.First().Key;
string param = sqb.Select().AddValue(columnName).From().AddValue(table.TableName).OrderBY().
AddValue(columnName).Asc().Limit().AddValue(rows.ToString()).Flush();
sqb.Delete().From().AddValue(table.TableName).Where().AddValue(columnName).In().Brackets(param);
CommitQuery(sqb.ToString());
}
/// <summary>
/// Gets all rows in the given id slot.
/// <para/>
/// SQL query Example: <para/>
/// SELECT * from table3 where id >= 0 and id -= 1
/// </summary>
/// <param name="table"></param>
/// <param name="start"></param>
/// <param name="end"></param>
/// <returns></returns>
public override List <List <object> > GetRowsFromTableWithIndex(Table table, int start, int end)
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
sqb.Select().ALL().From().AddValue(table.TableName).Where().AddValue(table.Columns.First().Key);
sqb.GreaterThen().AddValue(start.ToString()).AND().AddValue(table.Columns.First().Key).LesserThen().AddValue(end.ToString());
List <List <object> > results = ReadQuery(sqb.ToString(), GenerateOutputValuesFromTable(table));
return(results);
}
/// <summary>
/// Get's the last n rows from the specified table.
/// <para/>
/// SQL query Example:<para/>
/// SELECT * FROM (SELECT * FROM name.table3 ORDER BY id DESC LIMIT 1) ORDER BY id ASC;
/// </summary>
/// <param name="rows">number of the rows to display.</param>
/// <param name="table">The table to get the values from.</param>
/// <param name="ascending">Ascending or descending by first param.</param>
/// <returns></returns>
public override List <List <object> > GetLastNRowsFromTable(Table table, int rows, bool ascending = true)
{
try
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
sqb.Select().ALL().From().AddValue(table.TableName).OrderBY().AddValue(table.Columns.First().Key).Desc().Limit().AddValue(rows.ToString());
if (ascending)
{
string value = sqb.Flush();
sqb.Select().ALL().From().Brackets(value).OrderBY().AddValue(table.Columns.First().Key).Asc();
}
List <List <object> > results = ReadQuery(sqb.ToString(), GenerateOutputValuesFromTable(table));
return(results);
}
catch (Exception)
{
throw;
}
}
static void Main(string[] args)
{
var builder = new SQLQueryBuilder();
var selectQuery = builder.
Select("students.name", "age", "major", "course", "grade").
Distinct().
From("students").
InnerJoin("grades", ("students.name", "grades.name")).
Where("students.name", "grades.name").AND("students.name", "Markus").OR("students.name", "Joji").AND("age", "99").
OrderBy("students.name").
FinishQuery();
Console.WriteLine(selectQuery + "\r\n");
var updateQuery = builder.
Update("students").
Set(("age", "23")).
Where("name", "markus").
FinishQuery();
var selectQuery2 = builder.
Select("students.name", "course", "grade", "age", "major").
Distinct().
From("students", "grades").
Where("students.name", "grades.name").
OrderBy("major").
FinishQuery();
Console.WriteLine(updateQuery + "\r\n");
Console.WriteLine(selectQuery2 + "\r\n");
//string connectionString = @"Server=(localdb)\MyInstance;Initial Catalog = Local;Integrated Security=true;";
//bool usePostgress = false;
//ExecuteQuery(usePostgress, connectionString, updateQuery);
//ExecuteQuery(usePostgress, connectionString, selectQuery);
//ExecuteQuery(usePostgress, connectionString, selectQuery2);
}
/// <summary>
/// Gets all rows in the given DateTime slot.
/// <para/>
/// SQL query Example: <para/>
/// select * from table3 where Date >= "2018-12-06 11:10:32.632" and Date -= "2018-12-06 12:05:57.526";
/// </summary>
/// <param name="table">The name of the table to get the data from.</param>
/// <param name="DateTimeColumnName">The name of the column with the DateTime values.</param>
/// <param name="from">A DateTime object with the beginning of the timeslot.</param>
/// <param name="until">A DateTime object with the end of the timeslot.</param>
/// <returns></returns>
public override List <List <object> > GetRowsFromTableWithTime(Table table, string DateTimeColumnName, DateTime from, DateTime until)
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
string stringFrom = sqb.Apostrophe(from.ToString(_stringFormat)).Flush();
string stringUntil = sqb.Apostrophe(until.ToString(_stringFormat)).Flush();
sqb.Select().ALL().From().AddValue(table.TableName).Where().AddValue(DateTimeColumnName);
sqb.GreaterThen().AddValue(stringFrom).AND().AddValue(DateTimeColumnName).LesserThen().AddValue(stringUntil);
List <List <object> > results = ReadQuery(sqb.ToString(), GenerateOutputValuesFromTable(table));
return(results);
}
/// <summary>
/// If the current rowCount value is higher then the MaxRows value the deletion will be started.
/// Now the size of the table will be shrinked to 70% of the MaxRows value. The oldest values will be deleted.
/// If the amount of the rows to be deleted is higher than the global _maxDeleteRowSize then only every 5 seconds the highest amount possible
/// will be deleted until the initial calculated amountToDelete is 0.
/// <para/>
/// Example: <para/>
/// If you have 50 000 000 as MaxRows defined. Then 70% would be 35 000 000 rows. So 15 000 000 would have to be deleted.
/// If youre _maxDeleteRowSize is 100 000 this would mean 150 turns every 5 seconds. This would take then round about 12,5 minutes to delete all of them.
/// If you calculated with 500 entries per second. This would only mean 375 000 entries in these 12,5 minutes.
/// So this should be enough time to delete all entries with plenty of time in between for other sources to write to the database.
/// </summary>
/// <param name="tables">All saved tables.</param>
public override void CheckDeleteTables(ConcurrentDictionary <string, Table> tables)
{
try
{
foreach (Table table in tables.Values)
{
// Get the current row value
long result = GetCurrentRowsFromTable(table);
if (result >= table.MaxRows)
{
// Calculate 70% and the amount to delete
double seventyPercent = (double)table.MaxRows * (double)0.7;
long amountToDelete = result - (long)Math.Round(seventyPercent);
string text = "Started to delete entries on table: " + table.TableName + Environment.NewLine;
text += "Current Rows: " + result + " | Max table rows: " + table.MaxRows + " | Amount to delete: " + amountToDelete;
OnDeleteEvent(text);
while (amountToDelete > 0)
{
long rows;
if (amountToDelete > MaxDeleteRowSize)
{
rows = MaxDeleteRowSize;
}
else
{
rows = amountToDelete;
}
amountToDelete -= rows;
SQLQueryBuilder sqb = new SQLQueryBuilder();
string columnName = table.Columns.First().Key;
string param = sqb.Select().Top().AddValue(rows.ToString()).AddValue(columnName).From().AddValue(table.TableName)
.OrderBY().AddValue(columnName).Desc().Flush();
sqb.Delete().From().AddValue(table.TableName).Where().AddValue(columnName).In().Brackets(param);
CommitQuery(sqb.ToString());
Thread.Sleep(5000);
}
OnDeleteEvent("Finished the Deletion of the table: " + table.TableName);
}
}
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// Deletes the last n rows of the given table.
/// </summary>
/// <param name="table">The table to delete the last n data from.</param>
/// <param name="rows">The amount of data to delete.</param>
public override void DeleteLastNRows(Table table, int rows)
{
// TODO: Check Query
try
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
string columnName = table.Columns.First().Key;
string param = sqb.Select().Top().AddValue(rows.ToString()).AddValue(columnName).From().AddValue(table.TableName)
.OrderBY().AddValue(columnName).Desc().Flush();
sqb.Delete().From().AddValue(table.TableName).Where().AddValue(columnName).In().Brackets(param);
CommitQuery(sqb.ToString());
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// Gets all rows in the given id slot.
/// <para/>
/// </summary>
/// <param name="table"></param>
/// <param name="start"></param>
/// <param name="end"></param>
/// <param name="ascending">Ascending or descending by first param.</param>
/// <returns></returns>
public override List <List <object> > GetRowsFromTableWithIndex(Table table, int start, int end, bool ascending = true)
{
try
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
sqb.Select().ALL().From().AddValue(table.TableName).Where().AddValue(table.Columns.First().Key);
sqb.GreaterThen().AddValue(start.ToString()).AND().AddValue(table.Columns.First().Key).LesserThen().AddValue(end.ToString());
if (!ascending)
{
sqb.OrderBY().AddValue(table.Columns.First().Key).Desc();
}
List <List <object> > results = ReadQuery(sqb.ToString(), GenerateOutputValuesFromTable(table));
return(results);
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// Gets all rows in the given DateTime slot.
/// <para/>
/// </summary>
/// <param name="table">The name of the table to get the data from.</param>
/// <param name="DateTimeColumnName">The name of the column with the DateTime values.</param>
/// <param name="from">A DateTime object with the beginning of the timeslot.</param>
/// <param name="until">A DateTime object with the end of the timeslot.</param>
/// <param name="ascending">Ascending or descending by DateTimeColumn param.</param>
/// <returns></returns>
public override List <List <object> > GetRowsFromTableWithTime(Table table, string DateTimeColumnName, DateTime from, DateTime until, bool ascending = true)
{
try
{
SQLQueryBuilder sqb = new SQLQueryBuilder();
string stringFrom = sqb.Tags(from.ToString(_stringFormat)).Flush();
string stringUntil = sqb.Tags(until.ToString(_stringFormat)).Flush();
sqb.Select().ALL().From().AddValue(table.TableName).Where().AddValue(DateTimeColumnName);
sqb.GreaterThen().AddValue(stringFrom).AND().AddValue(DateTimeColumnName).LesserThen().AddValue(stringUntil);
if (!ascending)
{
sqb.OrderBY().AddValue(DateTimeColumnName).Desc();
}
List <List <object> > results = ReadQuery(sqb.ToString(), GenerateOutputValuesFromTable(table));
return(results);
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// Gets called if the Timer.Elapsed event is raised.
/// If the current rowCount value is higher then the MaxRows value in each table a deleteThread will be started.
/// Now the size of the table will be shrinked to 70% of the MaxRows value. The oldest values will be deleted.
/// If the amount of the rows to be deleted is higher than the global _maxDeleteRowSize then only every 5 seconds the highest amount possible
/// will be deleted until the the initial calculated RowsToDelete, which is stored in the Table object, is 0.
/// The thread is also stored in a global Dictionary so it can be aborted.
/// Every table can only have one DeleteThread active which is marked with the DeleteThreadActive variable.
/// <para/>
/// Example: <para/>
/// If you have 50 000 000 as MaxRows defined. Then 70% would be 35 000 000 rows. So 15 000 000 would have to be deleted.
/// If youre _maxDeleteRowSize is 100 000 this would mean 150 turns every 5 seconds. This would take then round about 12,5 minutes to delete all of them.
/// If you calculated with 500 entries per second. This would only mean 375 000 entries in these 12,5 minutes.
/// So this should be enough time to delete all entries with plenty of time in between for other sources to write to the database.
/// </summary>
/// <param name="tables">All saved tables.</param>
public override void OnDeleteTimer(Dictionary <string, Table> tables)
{
foreach (Table table in tables.Values)
{
long result = GetCurrentRowsFromTable(table);
if (result == 0)
{
continue;
}
if (result >= table.MaxRows)
{
// Calculate 70% and the amount to delete
double seventyPercent = (double)table.MaxRows * (double)0.7;
long amountToDelete = result - (long)Math.Round(seventyPercent);
Console.WriteLine(result + ">= " + table.MaxRows + " -> Clear the table: " + table.TableName);
// Start the Thread if it isn't active allready
if (!table.DeleteThreadActive)
{
table.RowsToDelete = amountToDelete;
table.DeleteThreadActive = true;
Thread deleteThread = new Thread(() =>
{
try
{
while (table.RowsToDelete > 0)
{
long rows;
if (table.RowsToDelete > MaxDeleteRowSize)
{
rows = MaxDeleteRowSize;
}
else
{
rows = table.RowsToDelete;
}
table.RowsToDelete -= rows;
SQLQueryBuilder deleteQuery = new SQLQueryBuilder();
string columnName = table.Columns.First().Key;
string param = deleteQuery.Select().AddValue(columnName).From().AddValue(table.TableName).OrderBY().
AddValue(columnName).Asc().Limit().AddValue(rows.ToString()).Flush();
deleteQuery.Delete().From().AddValue(table.TableName).Where().AddValue(columnName).In().Brackets(param);
CommitQuery(deleteQuery.ToString());
Console.WriteLine("Delete Thread deleted {0} rows!", rows);
Thread.Sleep(5000);
}
table.DeleteThreadActive = false;
_tableDeleteThreads.Remove(table.TableName);
}
catch (Exception)
{
}
});
_tableDeleteThreads.Add(table.TableName, deleteThread);
deleteThread.Start();
Console.WriteLine("Started Thread on: " + table.TableName);
}
}
}
}
