private SqlFragment GenericFunction(Dictionary <string, string> funcs,
DbFunctionExpression e)
{
SqlFragment[] frags = new SqlFragment[e.Arguments.Count];
for (int i = 0; i < e.Arguments.Count; i++)
{
frags[i] = e.Arguments[i].Accept(callingGenerator);
}
string sql;
switch (e.Function.Name)
{
case "Round":
// Special handling for Round as it has more than one signature.
sql = HandleFunctionRound(e);
break;
default:
sql = String.Format(funcs[e.Function.Name], frags);
break;
}
return(new LiteralFragment(sql));
}
private SqlFragment HandleFunction(DbFunctionAggregate fa, SqlFragment arg)
{
Debug.Assert(fa.Arguments.Count == 1);
if (fa.Function.NamespaceName != "Edm")
{
throw new NotSupportedException();
}
FunctionFragment fragment = new FunctionFragment();
fragment.Name = fa.Function.Name;
if (fa.Function.Name == "BigCount")
{
fragment.Name = "COUNT";
}
else
{
fragment.Name = fa.Function.Name.ToUpperInvariant();
}
fragment.Distinct = fa.Distinct;
fragment.Argument = arg;
return(fragment);
//return new CastExpression(aggregate, GetDbType(functionAggregate.ResultType.EdmType));
}
public void AddGroupBy(SqlFragment f)
{
if (GroupBy == null)
{
GroupBy = new List <SqlFragment>();
}
GroupBy.Add(f);
}
public override SqlFragment Visit(DbConstantExpression expression)
{
SqlFragment value = null;
if (_onReturningSelect && values.TryGetValue(_columnsVisited.Peek(), out value))
{
if (value is LiteralFragment)
{
MySqlParameter par = Parameters.Find(p => p.ParameterName == (value as LiteralFragment).Literal);
if (par != null)
{
return(new LiteralFragment(par.ParameterName));
}
}
}
return(base.Visit(expression));
}
public override string GenerateSQL(DbCommandTree tree)
{
DbQueryCommandTree commandTree = tree as DbQueryCommandTree;
SqlFragment fragment = null;
DbExpression e = commandTree.Query;
switch (commandTree.Query.ExpressionKind)
{
case DbExpressionKind.Project:
fragment = e.Accept(this);
Debug.Assert(fragment is SelectStatement);
break;
}
// Apply post-optimizations here:
fragment = TryFlatteningGroupBy(fragment);
return(fragment.ToString());
}
public override string GenerateSQL(DbCommandTree tree)
{
DbInsertCommandTree commandTree = tree as DbInsertCommandTree;
InsertStatement statement = new InsertStatement();
DbExpressionBinding e = commandTree.Target;
statement.Target = (InputFragment)e.Expression.Accept(this);
scope.Add("target", statement.Target);
foreach (DbSetClause setClause in commandTree.SetClauses)
{
statement.Sets.Add(setClause.Property.Accept(this));
}
if (values == null)
{
values = new Dictionary <EdmMember, SqlFragment>();
}
foreach (DbSetClause setClause in commandTree.SetClauses)
{
DbExpression value = setClause.Value;
SqlFragment valueFragment = value.Accept(this);
statement.Values.Add(valueFragment);
if (value.ExpressionKind != DbExpressionKind.Null)
{
EdmMember property = ((DbPropertyExpression)setClause.Property).Property;
values.Add(property, valueFragment);
}
}
if (commandTree.Returning != null)
{
statement.ReturningSelect = GenerateReturningSql(commandTree, commandTree.Returning);
}
return(statement.ToString());
}
public override string GenerateSQL(DbCommandTree tree)
{
DbUpdateCommandTree commandTree = tree as DbUpdateCommandTree;
UpdateStatement statement = new UpdateStatement();
_onReturningSelect = false;
statement.Target = commandTree.Target.Expression.Accept(this);
scope.Add("target", statement.Target as InputFragment);
if (values == null)
{
values = new Dictionary <EdmMember, SqlFragment>();
}
foreach (DbSetClause setClause in commandTree.SetClauses)
{
statement.Properties.Add(setClause.Property.Accept(this));
DbExpression value = setClause.Value;
SqlFragment valueFragment = value.Accept(this);
statement.Values.Add(valueFragment);
if (value.ExpressionKind != DbExpressionKind.Null)
{
EdmMember property = ((DbPropertyExpression)setClause.Property).Property;
values.Add(property, valueFragment);
}
}
statement.Where = commandTree.Predicate.Accept(this);
_onReturningSelect = true;
if (commandTree.Returning != null)
{
statement.ReturningSelect = GenerateReturningSql(commandTree, commandTree.Returning);
}
return(statement.ToString());
}
/// <summary>
/// If input sqlFragment is a group by structure, is flattened to remove some nested correlation queries.
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
private SqlFragment TryFlatteningGroupBy(SqlFragment input)
{
SelectStatement select = null;
SelectStatement tmpFrag = null, tmpFrag2 = null, tmpFrag3 = null;
InputFragment table = null;
string objName = null, colName = null, queryName = null;
// First part assert is a kind-of structure we are looking for
tmpFrag = input as SelectStatement;
if (tmpFrag == null)
{
goto NoChanges;
}
tmpFrag = (tmpFrag).From as SelectStatement;
if (tmpFrag == null)
{
goto NoChanges;
}
queryName = tmpFrag.Name;
if (tmpFrag.Columns.Count < 2)
{
goto NoChanges;
}
if (!(tmpFrag.Columns[0] is ColumnFragment))
{
goto NoChanges;
}
colName = objName = (tmpFrag.Columns[0] as ColumnFragment).ActualColumnName;
tmpFrag2 = tmpFrag.From as SelectStatement;
if (tmpFrag2 == null)
{
goto NoChanges;
}
if (tmpFrag2.Columns.Count < 1 || !(tmpFrag2.Columns[0] is ColumnFragment))
{
goto NoChanges;
}
if (string.CompareOrdinal(objName, tmpFrag2.Columns[0].ActualColumnName) != 0)
{
goto NoChanges;
}
if (tmpFrag.Columns[1].Literal == null)
{
goto NoChanges;
}
tmpFrag2 = tmpFrag.Columns[1].Literal as SelectStatement;
if (tmpFrag2 == null)
{
goto NoChanges;
}
if ((tmpFrag2.Columns.Count != 1) || !(tmpFrag2.Columns[0].Literal != null))
{
goto NoChanges;
}
tmpFrag3 = tmpFrag2.From as SelectStatement;
if (tmpFrag3 == null)
{
goto NoChanges;
}
table = tmpFrag3.From as InputFragment;
if (table == null)
{
goto NoChanges;
}
FunctionFragment func = tmpFrag2.Columns[0].Literal as FunctionFragment;
if (tmpFrag3.Columns.Count != 1 || !(tmpFrag3.Columns[0] is ColumnFragment))
{
goto NoChanges;
}
if (func == null)
{
goto NoChanges;
}
// Yes it is the kind-of type we like, then optimize it
select = new SelectStatement(this);
table.Name = null;
string tableName = null;
TableFragment t = tmpFrag3.From as TableFragment;
if (t == null)
{
tableName = tmpFrag3.Columns[0].TableName;
}
else
{
tableName = t.Table;
}
select.From = table;
select.Columns.Add(new ColumnFragment(tableName, colName));
select.Columns.Add(new ColumnFragment(tableName, "C0")
{
ColumnAlias = "C1",
Literal = new FunctionFragment()
{
Argument = new ColumnFragment(tableName, tmpFrag3.Columns[0].ActualColumnName),
Distinct = tmpFrag3.IsDistinct,
Name = func.Name
}
});
select.Wrap(null);
select.Name = queryName;
select.AddGroupBy(select.Columns[0]);
(input as SelectStatement).From = select;
NoChanges:
return(input);
}
public SortFragment(SqlFragment column, bool ascending)
{
Column = column;
Ascending = ascending;
}
public void Append(SqlFragment s)
{
Fragments.Add(s);
}
public ExistsFragment(SqlFragment f)
{
Argument = f;
}
