// drop statement
private void HandleStatement(DropStatement statement)
{
_catalogManager.CheckValidation(statement);
SchemaRecord schema;
switch (statement.TargetType)
{
case DropTarget.Table:
schema = _catalogManager.GetTableSchemaRecord(statement.TableName);
List <SchemaRecord> indices = _catalogManager.GetIndicesSchemaRecord(statement.TableName);
// drop table
_catalogManager.DropStatement(statement);
_recordManager.DropTable(schema.RootPage);
// drop index trees
foreach (SchemaRecord index in indices)
{
_recordManager.DropTable(index.RootPage);
}
break;
case DropTarget.Index:
schema = _catalogManager.GetIndexSchemaRecord(statement.IndexName);
_catalogManager.DropStatement(statement);
_recordManager.DropTable(schema.RootPage);
break;
}
}
public void DropStatementForTable(DropStatement dropStatement)
{
bool if_find = false;
if (this.If_in(dropStatement.TableName))
{
for (int i = 0; i < this.tables.Count;)
{
if (this.tables[i].table_name == dropStatement.TableName)
{
tables.RemoveAt(i);
Save_table(tables);
if_find = true;
}
else
{
i++;
}
}
}
//delete all the indices that are related to the deleted table
Catalog_index b = new Catalog_index(_databaseName);
if (if_find)
{
b.DeleteIndicesOfTable(dropStatement.TableName);
}
else
{
throw new TableOrIndexNotExistsException($"Table {dropStatement.TableName} Not Exists");
}
}
//try to drop one table and save the result into the file
//if succeed, return true
//if can't find table, return false
public bool TryDropStatementForTable(DropStatement dropStatement)
{
bool if_find = false;
if (this.If_in(dropStatement.TableName))
{
for (int i = 0; i < this.tables.Count;)
{
if (this.tables[i].table_name == dropStatement.TableName)
{
tables.RemoveAt(i);
Save_table(tables);
if_find = true;
}
else
{
i++;
}
}
}
//delete all the indices that are related to the deleted table
Catalog_index b = new Catalog_index(_databaseName);
return(if_find && b.DeleteIndicesOfTable(dropStatement.TableName));
}
public override object VisitDropTable([NotNull] MiniSQLParser.DropTableContext context)
{
DropStatement obj = new DropStatement();
obj.TargetType = DropTarget.Table;
obj.TableName = context.tableRef().GetText();
return(obj);
}
// try to remove some schema records from file
// if succeeded, return true. Vice versa
public bool TryDropStatement(DropStatement dropStatement)
{
try
{
DropStatement(dropStatement);
return(true);
}
catch (Exception)
{
return(false);
}
}
public override object VisitDropIndex([NotNull] MiniSQLParser.DropIndexContext context)
{
DropStatement obj = new DropStatement();
obj.TargetType = DropTarget.Index;
if (context.tableRef() != null)
{
obj.TableName = context.tableRef().GetText();
}
obj.IndexName = context.indexRef().GetText();
return(obj);
}
public void DropStatement(DropStatement dropStatement)
{
if (dropStatement.TargetType == DropTarget.Table)
{
Catalog_table a = new Catalog_table(_databaseName);//load the table
a.DropStatementForTable(dropStatement);
}
else
{
Catalog_index b = new Catalog_index(_databaseName);//load the index
b.DropStatementForIndex(dropStatement);
}
}
public void DropStatementForIndex(DropStatement dropStatement)
{
//if the index hasn't been created before, return false
if (!this.If_in(dropStatement.IndexName))
{
throw new TableOrIndexNotExistsException($"Index {dropStatement.IndexName} Not Exists");
}
for (int i = 0; i < index.Count;)
{
if (index[i].index_name == dropStatement.IndexName)
{
index.RemoveAt(i);
break;
}
else
{
i++;
}
}
Save_index(this.index);
}
static bool CheckDrop()
{
//make a drop statement for a index
//delete this index before delete the table, return true
DropStatement test_drop_index = new DropStatement();
test_drop_index.TargetType = DropTarget.Index;
test_drop_index.IndexName = "index_for_student_id";
bool test4 = icatalog.TryDropStatement(test_drop_index);
// Console.WriteLine("Delete Index1, expecting true:");
// Console.WriteLine(test4);
Debug.Assert(test4 == true);
//make a drop statement for a table
//delete this table and its assotiated indices, return true
DropStatement test_drop_table = new DropStatement();
test_drop_table.TargetType = DropTarget.Table;
test_drop_table.TableName = "Student";
bool test3 = icatalog.TryDropStatement(test_drop_table);
// Console.WriteLine("Delete table, expecting true:");
// Console.WriteLine(test3);
Debug.Assert(test3 == true);
//make a drop statement for a index
//delete this
DropStatement test_drop_index2 = new DropStatement();
test_drop_index2.TargetType = DropTarget.Index;
test_drop_index2.IndexName = "index2";
bool test5 = icatalog.TryDropStatement(test_drop_index2);
// Console.WriteLine("Delete index2 after deleting table, expecting false:");
// Console.WriteLine(test5);
Debug.Assert(test5 == false);
return(true);
}
public bool TryDropStatementForIndex(DropStatement dropStatement)
{
//if the index hasn't been created before, return false
if (!this.If_in(dropStatement.IndexName))
{
return(false);
}
for (int i = 0; i < index.Count;)
{
if (index[i].index_name == dropStatement.IndexName)
{
index.RemoveAt(i);
break;
}
else
{
i++;
}
}
Save_index(this.index);
return(true);
}
// check validation of the statement
public void CheckValidation(IStatement statement)
{
//check validation of createStatement
if (statement.Type == StatementType.CreateStatement)
{
CreateStatement x = (CreateStatement)statement;
//to create a table
if (x.CreateType == CreateType.Table)
{
// primary key not exists
if (x.PrimaryKey == null || x.PrimaryKey == "")
{
throw new KeyNotExistsException($"Table \"{x.TableName}\" does not have a primary key");
}
//to check whether the table has been created before
Catalog_table a = new Catalog_table(_databaseName);
a.AssertNotExist(x.TableName);
}
//to create an index
else
{
// index key not exists
if (x.AttributeName == null || x.AttributeName == "")
{
throw new KeyNotExistsException($"Index \"{x.IndexName}\" does not have a index key");
}
Catalog_table a = new Catalog_table(_databaseName);
Catalog_index b = new Catalog_index(_databaseName);
//to check whether the table exists
bool condition1 = a.If_in(x.TableName);
//to check whether the index has been created before
bool condition2 = !b.If_in(x.IndexName);
//to check whether the attribute is in the attribute list of the table
bool condition3 = a.return_table(x.TableName).Has_attribute(x.AttributeName);
if (!condition1)
{
throw new TableOrIndexNotExistsException($"Table \"\"{x.TableName}\"\" not exists");
}
if (!condition2)
{
throw new TableOrIndexAlreadyExistsException($"Index \"\"{x.IndexName}\"\" not exists");
}
if (!condition3)
{
throw new AttributeNotExistsException($"Attribute \"\"{x.AttributeName}\"\" not exists in table \"\"{x.TableName}\"\"");
}
}
}
//check validation of a drop statement
else if (statement.Type == StatementType.DropStatement)
{
DropStatement x = (DropStatement)statement;
Catalog_table a = new Catalog_table(_databaseName);
Catalog_index b = new Catalog_index(_databaseName);
//to drop a table,we need to check whether the table exists
if (x.TargetType == DropTarget.Table)
{
a.AssertExist(x.TableName);
}
//to drop a index,we need to check whether the index exists
else
{
if (x.TableName != "")
{
b.AssertExist(x.IndexName);
if (b.Of_table(x.IndexName) != x.TableName)
{
throw new AttributeNotExistsException($"Index \"{x.IndexName}\" is not associated with table \"{x.TableName}\"");
}
}
else
{
b.AssertExist(x.IndexName);
}
}
}
//check validation of a select statement
else if (statement.Type == StatementType.SelectStatement)
{
SelectStatement x = (SelectStatement)statement;
//check whether the table is in the tables catalog
Catalog_table a = new Catalog_table(_databaseName);
a.AssertExist(x.FromTable);
if (x.Condition == null)
{
return;
}
else if (x.Condition.AttributeName == "")
{
if (x.Condition.SimpleMinterms.Count == 0)
{
//if the ands is empty and attribute name is emply, the statement means select * from a table
return;
}
else
{
//for each attribute in the egression list(named 'ands')
//check whether the attribute is in the attribute list of this table
foreach (KeyValuePair <string, Expression> expression_piece in x.Condition.SimpleMinterms)
{
if (!a.return_table(x.FromTable).Has_attribute(expression_piece.Key))
{
throw new AttributeNotExistsException($"Attribute \"{expression_piece.Key}\" not exists in table \"{x.FromTable}\"");
}
}
}
}
else
{
//check whether the only attribute is one of the table's attributes
if (!a.return_table(x.FromTable).Has_attribute(x.Condition.AttributeName))
{
throw new AttributeNotExistsException($"Attribute \"{x.Condition.AttributeName}\" not exists in table \"{x.FromTable}\"");
}
}
return;
}
//check validation of a delete statement
else if (statement.Type == StatementType.DeleteStatement)
{
DeleteStatement x = (DeleteStatement)statement;
//check whether the table is in the tables catalog
Catalog_table a = new Catalog_table(_databaseName);
a.AssertExist(x.TableName);
if (x.Condition == null)
{
return;
}
else if (x.Condition.AttributeName == "")
{
if (x.Condition.SimpleMinterms.Count == 0)
{
//if the ands is empty and attribute name is emply, the statement means select * from a table
return;
}
else
{
//for each attribute in the epression list(named 'ands')
//check whether the attribute is in the attribute list of this table
foreach (KeyValuePair <string, Expression> expression_piece in x.Condition.SimpleMinterms)
{
if (!a.return_table(x.TableName).Has_attribute(expression_piece.Key))
{
throw new AttributeNotExistsException($"Attribute \"{expression_piece.Key}\" not exists in table \"{x.TableName}\"");
}
}
}
}
else
{
//check whether the only attribute is one of the table's attributes
if (!a.return_table(x.TableName).Has_attribute(x.Condition.AttributeName))
{
throw new AttributeNotExistsException($"Attribute \"{x.Condition.AttributeName}\" not exists in table \"{x.TableName}\"");
}
}
return;
}
//check validation of an insert statement
else if (statement.Type == StatementType.InsertStatement)
{
InsertStatement x = (InsertStatement)statement;
//check whether the table is in the table list
Catalog_table a = new Catalog_table(_databaseName);
a.AssertExist(x.TableName);
//check if the number of the attributes perfectly match the number of the values
if (x.Values.Count != a.return_table(x.TableName).attribute_list.Count)
{
throw new NumberOfAttributesNotMatchsException($"Number of attributes not matchs. Expected: \"{a.return_table(x.TableName).attribute_list.Count}\"; actual: \"{x.Values.Count}\"");
}
//check whether the type of the inserted data well suits the data definition of each attribute
for (int i = 0; i < x.Values.Count; i++)
{
if (a.return_table(x.TableName).attribute_list[i].type != x.Values[i].Type)
{
throw new TypeOfAttributeNotMatchsException($"Type for attribute \"{a.return_table(x.TableName).attribute_list[i].attribute_name}\" not matches. Expected: \"{a.return_table(x.TableName).attribute_list[i].type}\"; actual: \"{x.Values[i].Type}\"");
}
}
//if all data type suit, return true
return;
}
//check validation of a quit statement
else if (statement.Type == StatementType.QuitStatement)
{
return;
}
//check validation of an exec file statement
else
{
return;
}
}
//check if the program can successfully check the validation of each kind of input statement
static bool CheckValidation()
{ //since quitstatement and execfile statement are too simple,we skip them here
Catalog func = new Catalog("test");
//select statement
//3 kinds, each with a true and a false version
//select only from table without any attribute
SelectStatement select_only_table_true = new SelectStatement();
// select_only_table_true.Condition = new Expression();
select_only_table_true.FromTable = "Student";
SelectStatement select_only_table_false = new SelectStatement();
// select_only_table_false.Condition = new Expression();
select_only_table_false.FromTable = "School";
bool test1 = func.IsValid(select_only_table_false);
bool test2 = func.IsValid(select_only_table_true);
// Console.WriteLine(" Wrong select statement that select only 1 table, expecting false:");
// Console.WriteLine(test1);
Debug.Assert(test1 == false);
// Console.WriteLine(" Right select statement that select only 1 table, expecting true:");
// Console.WriteLine(test2);
Debug.Assert(test2 == true);
//select from table with 1 attribute
SelectStatement select_with_1_attribute_true = new SelectStatement();
select_with_1_attribute_true.FromTable = "Student";
select_with_1_attribute_true.Condition = new Expression();
select_with_1_attribute_true.Condition.Operator = Operator.AtomVariable;
select_with_1_attribute_true.Condition.AttributeName = "ID";
SelectStatement select_with_1_attribute_false = new SelectStatement();
select_with_1_attribute_false.FromTable = "Student";
select_with_1_attribute_false.Condition = new Expression();
select_with_1_attribute_true.Condition.Operator = Operator.AtomVariable;
select_with_1_attribute_false.Condition.AttributeName = "Gender";
bool test3 = icatalog.IsValid(select_with_1_attribute_true);
bool test4 = icatalog.IsValid(select_with_1_attribute_false);
// Console.WriteLine("Right select statement that select with 1 attribute, expecting true:");
// Console.WriteLine(test3);
Debug.Assert(test3 == true);
// Console.WriteLine("Wrong select statement that select with 1 attribute, expecting false:");
// Console.WriteLine(test4);
Debug.Assert(test4 == false);
// select from table with condition having 3 attribute
SelectStatement select_with_3_attribute_true = new SelectStatement();
select_with_3_attribute_true.FromTable = "Student";
select_with_3_attribute_true.Condition = GetExpression("ID", "Class", "Score");
SelectStatement select_with_3_attribute_false = new SelectStatement();
select_with_3_attribute_false.FromTable = "Student";
select_with_3_attribute_false.Condition = GetExpression("Gender", "Class", "Score");
bool test5 = icatalog.IsValid(select_with_3_attribute_true);
bool test6 = icatalog.IsValid(select_with_3_attribute_false);
// Console.WriteLine("Right select statement that select with 3 attributes, expecting true:");
// Console.WriteLine(test5);
Debug.Assert(test5 == true);
// Console.WriteLine("Wrong select statement that select with 3 attribute, expecting false:");
// Console.WriteLine(test6);
Debug.Assert(test6 == false);
//delete statement
//3 kinds, each with a true and a false version
//almost the same as the select statement
//delete table without any attribute
DeleteStatement delete_only_table_true = new DeleteStatement();
delete_only_table_true.TableName = "Student";
DeleteStatement delete_only_table_false = new DeleteStatement();
delete_only_table_false.TableName = "School";
bool tst1 = func.IsValid(delete_only_table_false);
bool tst2 = func.IsValid(delete_only_table_true);
// Console.WriteLine("Wrong delete statement that delete only table, expecting false:");
// Console.WriteLine(tst1);
Debug.Assert(tst1 == false);
// Console.WriteLine("Right delete statement that delete only table, expecting true:");
// Console.WriteLine(tst2);
Debug.Assert(tst2 == true);
//delete from table with 1 attribute
DeleteStatement delete_with_1_attribute_true = new DeleteStatement();
delete_with_1_attribute_true.TableName = "Student";
delete_with_1_attribute_true.Condition = new Expression()
{
Operator = Operator.AtomVariable
};
delete_with_1_attribute_true.Condition.AttributeName = "ID";
DeleteStatement delete_with_1_attribute_false = new DeleteStatement();
delete_with_1_attribute_false.Condition = new Expression()
{
Operator = Operator.AtomVariable
};
delete_with_1_attribute_false.TableName = "Student";
delete_with_1_attribute_false.Condition.AttributeName = "Gender";
bool tst3 = icatalog.IsValid(delete_with_1_attribute_true);
bool tst4 = icatalog.IsValid(delete_with_1_attribute_false);
// Console.WriteLine("Right delete statement that delete with 1 attribute, expecting true:");
// Console.WriteLine(tst3);
Debug.Assert(tst3 == true);
// Console.WriteLine("Wrong delete statement that delete with 1 attribute, expecting false:");
// Console.WriteLine(tst4);
Debug.Assert(tst4 == false);
//delete from table with 3 attribute
DeleteStatement delete_with_3_attribute_true = new DeleteStatement();
delete_with_3_attribute_true.Condition = GetExpression("ID", "Class", "Score");
delete_with_3_attribute_true.TableName = "Student";
DeleteStatement delete_with_3_attribute_false = new DeleteStatement();
delete_with_3_attribute_false.TableName = "Student";
delete_with_3_attribute_false.Condition = GetExpression("ID", "Gender", "Score");
bool tst5 = icatalog.IsValid(delete_with_3_attribute_true);
bool tst6 = icatalog.IsValid(delete_with_3_attribute_false);
// Console.WriteLine("Right delete statement that delete with 3 attribute, expecting true:");
// Console.WriteLine(tst5);
Debug.Assert(tst5 == true);
// Console.WriteLine("Wrong delete statement that delete with 3 attribute, expecting false:");
// Console.WriteLine(tst6);
Debug.Assert(tst6 == false);
//insert statement
//3 kinds, only the first is true, others are false
//all attributes suit
InsertStatement insert_all_suit = new InsertStatement();
insert_all_suit.TableName = "Student";
//make all the values into a list
List <AtomValue> insert_tmp1 = new List <AtomValue>();
AtomValue attribute_value1 = new AtomValue();
attribute_value1.Type = AttributeTypes.Char;
attribute_value1.StringValue = "111";
AtomValue attribute_value2 = new AtomValue();
attribute_value2.Type = AttributeTypes.Char;
attribute_value2.StringValue = "Lily";
AtomValue attribute_value3 = new AtomValue();
attribute_value3.Type = AttributeTypes.Float;
attribute_value3.FloatValue = 80.5;
AtomValue attribute_value4 = new AtomValue();
attribute_value4.Type = AttributeTypes.Int;
attribute_value4.IntegerValue = 5;
insert_tmp1.Add(attribute_value1);
insert_tmp1.Add(attribute_value2);
insert_tmp1.Add(attribute_value3);
insert_tmp1.Add(attribute_value4);
insert_all_suit.Values = insert_tmp1;
bool insert_test1 = icatalog.IsValid(insert_all_suit);
// Console.WriteLine("Right insert statement, expecting true:");
// Console.WriteLine(insert_test1);
Debug.Assert(insert_test1 == true);
//doesn't match the number of attributes
InsertStatement insert_wrong_number = new InsertStatement();
insert_wrong_number.TableName = "Student";
//get the value list of only 3 attributes when 4 is the right number
insert_tmp1.RemoveAt(3);
insert_wrong_number.Values = insert_tmp1;
bool insert_test2 = icatalog.IsValid(insert_wrong_number);
// Console.WriteLine("Wrong insert statement for wrong number of attributes, expecting false:");
// Console.WriteLine(insert_test2);
Debug.Assert(insert_test2 == false);
//doesn't match the type of attributes
InsertStatement insert_wrong_type = new InsertStatement();
insert_wrong_type.TableName = "Student";
//give attribute 4 type string instead of int
AtomValue attribute_value5 = new AtomValue();
attribute_value5.Type = AttributeTypes.Char;
attribute_value5.StringValue = "hhhh";
insert_tmp1.Add(attribute_value5);
insert_wrong_type.Values = insert_tmp1;
bool insert_test3 = icatalog.IsValid(insert_wrong_type);
// Console.WriteLine("Wrong insert statement for wrong type of attributes, expecting false:");
// Console.WriteLine(insert_test3);
Debug.Assert(insert_test3 == false);
//drop statement
//2 kind, try to drop a table or an index, each with a true and a false version
//drop an existing table, true
DropStatement drop_table_true = new DropStatement();
drop_table_true.TargetType = DropTarget.Table;
drop_table_true.TableName = "Student";
bool drop_test1 = icatalog.IsValid(drop_table_true);
// Console.WriteLine("Right drop table statement, expecting true:");
// Console.WriteLine(drop_test1);
Debug.Assert(drop_test1 == true);
//drop a table that doesn't exist, false
DropStatement drop_table_false = new DropStatement();
drop_table_false.TargetType = DropTarget.Table;
drop_table_false.TableName = "School";
bool drop_test2 = icatalog.IsValid(drop_table_false);
// Console.WriteLine("Wrong drop table statement, expecting false:");
// Console.WriteLine(drop_test2);
Debug.Assert(drop_test2 == false);
//drop an existing index from the table that doesn't exist, false
DropStatement drop_index_false1 = new DropStatement();
drop_index_false1.TargetType = DropTarget.Index;
drop_index_false1.IndexName = "index_for_student_id";
drop_index_false1.TableName = "School";
bool drop_test3 = icatalog.IsValid(drop_index_false1);
// Console.WriteLine("Wrong drop index statement that drop from the table that doesn't exist, expecting false:");
// Console.WriteLine(drop_test3);
Debug.Assert(drop_test3 == false);
//drop an index that doesn't exist, false
DropStatement drop_index_false2 = new DropStatement();
drop_index_false2.TargetType = DropTarget.Index;
drop_index_false2.IndexName = "index_wrong";
drop_index_false2.TableName = "Student";
bool drop_test4 = icatalog.IsValid(drop_index_false2);
// Console.WriteLine("Wrong drop index statement that drop an unknown index, expecting false:");
// Console.WriteLine(drop_test4);
Debug.Assert(drop_test4 == false);
//drop an index that exits, true
DropStatement drop_index_true = new DropStatement();
drop_index_true.TargetType = DropTarget.Index;
drop_index_true.IndexName = "index_for_student_id";
drop_index_true.TableName = "Student";
bool drop_test5 = icatalog.IsValid(drop_index_true);
// Console.WriteLine("Right drop index statement, expecting true:");
// Console.WriteLine(drop_test5);
Debug.Assert(drop_test5 == true);
//create statement
//2 kinds, for index and for table, each with both true and wrong version
//create a table
CreateStatement create_table_true = new CreateStatement();
create_table_true.CreateType = CreateType.Table;
create_table_true.TableName = "Home";
bool create_test1 = icatalog.IsValid(create_table_true);
// Console.WriteLine("Right create table statement, expecting true:");
// Console.WriteLine(create_test1);
Debug.Assert(create_test1 == true);
//create an index, true
CreateStatement create_index_true = new CreateStatement();
create_index_true.CreateType = CreateType.Index;
create_index_true.TableName = "Student";
create_index_true.IndexName = "second_index_for_student_id";
create_index_true.AttributeName = "ID";
bool create_test2 = icatalog.IsValid(create_index_true);
// Console.WriteLine("Right create index statement, expecting true:");
// Console.WriteLine(create_test2);
Debug.Assert(create_test2 == true);
//create an index that already exists, false
CreateStatement create_index_false1 = new CreateStatement();
create_index_false1.CreateType = CreateType.Index;
create_index_false1.TableName = "Student";
create_index_false1.IndexName = "index_for_student_id";
create_index_false1.AttributeName = "ID";
bool create_test3 = icatalog.IsValid(create_index_false1);
// Console.WriteLine("Wrong create index statement, expecting false:");
// Console.WriteLine(create_test3);
Debug.Assert(create_test3 == false);
//create an index for an attribute that doesn't eixst
CreateStatement create_index_false2 = new CreateStatement();
create_index_false2.CreateType = CreateType.Index;
create_index_false2.TableName = "Student";
create_index_false2.IndexName = "index_for_student_home";
create_index_false2.AttributeName = "Home";
bool create_test4 = icatalog.IsValid(create_index_false2);
// Console.WriteLine("Wrong create index statement that is created on an attribute that does not exist, expecting false:");
// Console.WriteLine(create_test4);
Debug.Assert(create_test4 == false);
//create an index for a table that doesn't eixst
CreateStatement create_index_false3 = new CreateStatement();
create_index_false3.CreateType = CreateType.Index;
create_index_false3.TableName = "Home";
create_index_false3.IndexName = "index_for_student_house";
create_index_false3.AttributeName = "Street";
bool create_test5 = icatalog.IsValid(create_index_false3);
// Console.WriteLine("Wrong create index statement that is created on a table that doesn't exist, expecting false:");
// Console.WriteLine(create_test5);
Debug.Assert(create_test5 == false);
return(true);
}