public override ITable Evaluate(IQueryContext context)
{
var childTable = Child.Evaluate(context);
var funTable = new FunctionTable(childTable, Functions, Names, context);
// If no columns then it is implied the whole table is the group.
if (ColumnNames == null) {
funTable = funTable.AsGroup();
} else {
funTable = funTable.CreateGroupMatrix(ColumnNames);
}
return funTable.MergeWith(GroupMaxColumn);
}
public TableGroupResolver(FunctionTable table)
{
this.table = table;
}
public static ITable Any(this ITable theTable, IQueryContext context, Expression expression, Operator op, Table rightTable)
{
ITable table = rightTable;
// Check the table only has 1 column
if (table.TableInfo.ColumnCount != 1)
{
throw new ApplicationException("Input table <> 1 columns.");
}
// Handle trivial case of no entries to select from
if (theTable.RowCount == 0)
{
return(theTable);
}
// If 'table' is empty then we return an empty set. ANY { empty set } is
// always false.
if (table.RowCount == 0)
{
return(theTable.EmptySelect());
}
// Is the lhs expression a constant?
if (expression.IsConstant())
{
// We know lhs is a constant so no point passing arguments,
DataObject value = expression.Evaluate(null, context);
// Select from the table.
IEnumerable <long> list = table.SelectRows(0, op, value);
if (list.Any())
{
// There's some entries so return the whole table,
return(theTable);
}
// No entries matches so return an empty table.
return(theTable.EmptySelect());
}
Table sourceTable;
int lhsColIndex;
// Is the lhs expression a single variable?
ObjectName expVar = expression.AsVariable();
// NOTE: It'll be less common for this part to be called.
if (expVar == null)
{
// This is a complex expression so make a FunctionTable as our new
// source.
FunctionTable funTable = new FunctionTable((Table)theTable, new Expression[] { expression }, new String[] { "1" }, context);
sourceTable = funTable;
lhsColIndex = 0;
}
else
{
// The expression is an easy to resolve reference in this table.
sourceTable = (Table)theTable;
lhsColIndex = sourceTable.FindFieldName(expVar);
if (lhsColIndex == -1)
{
throw new ApplicationException("Can't find column '" + expVar + "'.");
}
}
// Check that the first column of 'table' is of a compatible type with
// source table column (lhs_col_index).
// ISSUE: Should we convert to the correct type via a FunctionTable?
DataColumnInfo sourceCol = sourceTable.TableInfo[lhsColIndex];
DataColumnInfo destCol = table.TableInfo[0];
if (!sourceCol.DataType.IsComparable(destCol.DataType))
{
throw new ApplicationException("The type of the sub-query expression " +
sourceCol.DataType + " is incompatible " +
"with the sub-query " + destCol.DataType +
".");
}
// We now have all the information to solve this query.
// We work output as follows:
// For >, >= type ANY we find the lowest value in 'table' and
// select from 'source' all the rows that are >, >= than the
// lowest value.
// For <, <= type ANY we find the highest value in 'table' and
// select from 'source' all the rows that are <, <= than the
// highest value.
// For = type ANY we use same method from INHelper.
// For <> type ANY we iterate through 'source' only including those
// rows that a <> query on 'table' returns size() != 0.
IList <long> selectRows;
if (op.IsEquivalent(Operator.Greater) ||
op.IsEquivalent(Operator.GreaterOrEqual))
{
// Select the first from the set (the lowest value),
DataObject lowestCell = table.GetFirstCell(0);
// Select from the source table all rows that are > or >= to the
// lowest cell,
selectRows = sourceTable.SelectRows(lhsColIndex, op, lowestCell).ToList();
}
else if (op.IsEquivalent(Operator.Smaller) ||
op.IsEquivalent(Operator.SmallerOrEqual))
{
// Select the last from the set (the highest value),
DataObject highestCell = table.GetLastCell(0);
// Select from the source table all rows that are < or <= to the
// highest cell,
selectRows = sourceTable.SelectRows(lhsColIndex, op, highestCell).ToList();
}
else if (op.IsEquivalent(Operator.Equal))
{
// Equiv. to IN
selectRows = sourceTable.In(table, lhsColIndex, 0);
}
else if (op.IsEquivalent(Operator.NotEqual))
{
// Select the value that is the same of the entire column
DataObject cell = table.GetSingleCell(0);
if (cell != null)
{
// All values from 'source_table' that are <> than the given cell.
selectRows = sourceTable.SelectRows(lhsColIndex, op, cell).ToList();
}
else
{
// No, this means there are different values in the given set so the
// query evaluates to the entire table.
return(theTable);
}
}
else
{
throw new ApplicationException("Don't understand operator '" + op + "' in ANY.");
}
// Make into a table to return.
VirtualTable rtable = new VirtualTable((Table)theTable);
rtable.Set((Table)theTable, selectRows);
return(rtable);
}
public static ITable All(this ITable table, IQueryContext context, Expression expression, Operator op, ITable other)
{
// Check the table only has 1 column
if (other.TableInfo.ColumnCount != 1)
{
throw new ApplicationException("Input table <> 1 columns.");
}
// Handle trivial case of no entries to select from
if (table.RowCount == 0)
{
return(table);
}
var theTable = table as Table;
if (theTable == null)
{
return(table);
}
// If 'table' is empty then we return the complete set. ALL { empty set }
// is always true.
if (other.RowCount == 0)
{
return(table);
}
// Is the lhs expression a constant?
if (expression.IsConstant())
{
// We know lhs is a constant so no point passing arguments,
DataObject value = expression.Evaluate(context);
bool comparedToTrue;
// The various operators
if (op.IsEquivalent(Operator.Greater) ||
op.IsEquivalent(Operator.GreaterOrEqual))
{
// Find the maximum value in the table
DataObject cell = other.GetLastCell(0);
comparedToTrue = CompareCells(value, cell, op);
}
else if (op.IsEquivalent(Operator.Smaller) ||
op.IsEquivalent(Operator.SmallerOrEqual))
{
// Find the minimum value in the table
DataObject cell = other.GetFirstCell(0);
comparedToTrue = CompareCells(value, cell, op);
}
else if (op.IsEquivalent(Operator.Equal))
{
// Only true if rhs is a single value
DataObject cell = other.GetSingleCell(0);
comparedToTrue = (cell != null && CompareCells(value, cell, op));
}
else if (op.IsEquivalent(Operator.NotEqual))
{
// true only if lhs_cell is not found in column.
comparedToTrue = !other.ColumnContainsValue(0, value);
}
else
{
throw new ApplicationException("Don't understand operator '" + op + "' in ALL.");
}
// If matched return this table
if (comparedToTrue)
{
return(table);
}
// No entries matches so return an empty table.
return(table.EmptySelect());
}
Table sourceTable;
int colIndex;
// Is the lhs expression a single variable?
ObjectName expVar = expression.AsVariable();
// NOTE: It'll be less common for this part to be called.
if (expVar == null)
{
// This is a complex expression so make a FunctionTable as our new
// source.
DatabaseQueryContext dbContext = (DatabaseQueryContext)context;
FunctionTable funTable = new FunctionTable((Table)table, new[] { expression }, new [] { "1" }, dbContext);
sourceTable = funTable;
colIndex = 0;
}
else
{
// The expression is an easy to resolve reference in this table.
sourceTable = (Table)table;
colIndex = sourceTable.FindFieldName(expVar);
if (colIndex == -1)
{
throw new ApplicationException("Can't find column '" + expVar + "'.");
}
}
// Check that the first column of 'table' is of a compatible type with
// source table column (lhs_col_index).
// ISSUE: Should we convert to the correct type via a FunctionTable?
DataColumnInfo sourceCol = sourceTable.TableInfo[colIndex];
DataColumnInfo destCol = other.TableInfo[0];
if (!sourceCol.DataType.IsComparable(destCol.DataType))
{
throw new ApplicationException("The type of the sub-query expression " +
sourceCol.DataType + " is incompatible " +
"with the sub-query " + destCol.DataType +
".");
}
// We now have all the information to solve this query.
// We work output as follows:
// For >, >= type ALL we find the highest value in 'table' and
// select from 'source' all the rows that are >, >= than the
// highest value.
// For <, <= type ALL we find the lowest value in 'table' and
// select from 'source' all the rows that are <, <= than the
// lowest value.
// For = type ALL we see if 'table' contains a single value. If it
// does we select all from 'source' that equals the value, otherwise an
// empty table.
// For <> type ALL we use the 'not in' algorithm.
IList <long> selectList;
if (op.IsEquivalent(Operator.Greater) ||
op.IsEquivalent(Operator.GreaterOrEqual))
{
// Select the last from the set (the highest value),
DataObject highestCell = other.GetLastCell(0);
// Select from the source table all rows that are > or >= to the
// highest cell,
selectList = sourceTable.SelectRows(colIndex, op, highestCell).ToList();
}
else if (op.IsEquivalent(Operator.Smaller) ||
op.IsEquivalent(Operator.SmallerOrEqual))
{
// Select the first from the set (the lowest value),
DataObject lowestCell = other.GetFirstCell(0);
// Select from the source table all rows that are < or <= to the
// lowest cell,
selectList = sourceTable.SelectRows(colIndex, op, lowestCell).ToList();
}
else if (op.IsEquivalent(Operator.Equal))
{
// Select the single value from the set (if there is one).
DataObject singleCell = other.GetSingleCell(0);
if (singleCell != null)
{
// Select all from source_table all values that = this cell
selectList = sourceTable.SelectRows(colIndex, op, singleCell).ToList();
}
else
{
// No single value so return empty set (no value in LHS will equal
// a value in RHS).
return(table.EmptySelect());
}
}
else if (op.IsEquivalent(Operator.NotEqual))
{
// Equiv. to NOT IN
selectList = sourceTable.NotIn(other, colIndex, 0).ToList();
}
else
{
throw new ApplicationException("Don't understand operator '" + op + "' in ALL.");
}
// Make into a table to return.
VirtualTable rtable = new VirtualTable(theTable);
rtable.Set((Table)table, selectList);
return(rtable);
}
public override ITable Evaluate(IQueryContext context)
{
var childTable = Child.Evaluate(context);
var funTable = new FunctionTable(childTable, Functions, Names, context);
return funTable.MergeWith(null);
}
public TableGroupResolver(FunctionTable table)
{
this.table = table;
}
// ---------- Convenience statics ----------
///<summary>
/// Returns a FunctionTable that has a single Expression evaluated in it.
///</summary>
///<param name="context"></param>
///<param name="expression"></param>
/// <remarks>
/// The column name is 'result'.
/// </remarks>
///<returns></returns>
public static Table ResultTable(IQueryContext context, Expression expression)
{
Expression[] exp = new Expression[] { expression };
string[] names = new String[] {"result"};
Table function_table = new FunctionTable(exp, names, context);
SubsetColumnTable result = new SubsetColumnTable(function_table);
int[] map = new int[] {0};
ObjectName[] vars = new[] {new ObjectName("result")};
result.SetColumnMap(map, vars);
return result;
}
// ---------- Convenience statics ----------
///<summary>
/// Returns a FunctionTable that has a single Expression evaluated in it.
///</summary>
///<param name="context"></param>
///<param name="expression"></param>
/// <remarks>
/// The column name is 'result'.
/// </remarks>
///<returns></returns>
public static ITable ResultTable(IQueryContext context, Expression expression)
{
var exp = new Expression[] { expression };
var names = new String[] { "result" };
Table functionTable = new FunctionTable(exp, names, context);
var map = new int[] { 0 };
var vars = new ObjectName[] { new ObjectName("result") };
return new SubsetColumnTable(functionTable, map, vars);
}
public override ITable Evaluate(IQueryContext context)
{
ITable childTable = Child.Evaluate(context);
var dbContext = (DatabaseQueryContext)context;
var funTable = new FunctionTable((Table)childTable, functionList, nameList, dbContext);
// If no columns then it is implied the whole table is the group.
if (columns == null) {
funTable.SetWholeTableAsGroup();
} else {
funTable.CreateGroupMatrix(columns);
}
return funTable.MergeWithReference(groupMaxColumn);
}