ladybird/Userland/Libraries/LibSQL/SQLResult.h
Jan de Visser d074a601df LibSQL+SQLServer: Bare bones INSERT and SELECT statements
This patch provides very basic, bare bones implementations of the
INSERT and SELECT statements. They are *very* limited:
- The only variant of the INSERT statement that currently works is
   SELECT INTO schema.table (column1, column2, ....) VALUES
      (value11, value21, ...), (value12, value22, ...), ...
   where the values are literals.
- The SELECT statement is even more limited, and is only provided to
  allow verification of the INSERT statement. The only form implemented
  is: SELECT * FROM schema.table

These statements required a bit of change in the Statement::execute
API. Originally execute only received a Database object as parameter.
This is not enough; we now pass an ExecutionContext object which
contains the Database, the current result set, and the last Tuple read
from the database. This object will undoubtedly evolve over time.

This API change dragged SQLServer::SQLStatement into the patch.

Another API addition is Expression::evaluate. This method is,
unsurprisingly, used to evaluate expressions, like the values in the
INSERT statement.

Finally, a new test file is added: TestSqlStatementExecution, which
tests the currently implemented statements. As the number and flavour of
implemented statements grows, this test file will probably have to be
restructured.
2021-08-21 22:03:30 +02:00

145 lines
4.4 KiB
C++

/*
* Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/NonnullOwnPtrVector.h>
#include <AK/Vector.h>
#include <LibCore/Object.h>
#include <LibSQL/Tuple.h>
#include <LibSQL/Type.h>
namespace SQL {
#define ENUMERATE_SQL_COMMANDS(S) \
S(Create) \
S(Delete) \
S(Insert) \
S(Select) \
S(Update)
enum class SQLCommand {
#undef __ENUMERATE_SQL_COMMAND
#define __ENUMERATE_SQL_COMMAND(command) command,
ENUMERATE_SQL_COMMANDS(__ENUMERATE_SQL_COMMAND)
#undef __ENUMERATE_SQL_COMMAND
};
constexpr char const* command_tag(SQLCommand command)
{
switch (command) {
#undef __ENUMERATE_SQL_COMMAND
#define __ENUMERATE_SQL_COMMAND(command) \
case SQLCommand::command: \
return #command;
ENUMERATE_SQL_COMMANDS(__ENUMERATE_SQL_COMMAND)
#undef __ENUMERATE_SQL_COMMAND
}
}
#define ENUMERATE_SQL_ERRORS(S) \
S(NoError, "No error") \
S(DatabaseUnavailable, "Database Unavailable") \
S(StatementUnavailable, "Statement with id '{}' Unavailable") \
S(SyntaxError, "Syntax Error") \
S(DatabaseDoesNotExist, "Database '{}' does not exist") \
S(SchemaDoesNotExist, "Schema '{}' does not exist") \
S(SchemaExists, "Schema '{}' already exist") \
S(TableDoesNotExist, "Table '{}' does not exist") \
S(ColumnDoesNotExist, "Column '{}' does not exist") \
S(TableExists, "Table '{}' already exist") \
S(InvalidType, "Invalid type '{}'") \
S(InvalidDatabaseName, "Invalid database name '{}'")
enum class SQLErrorCode {
#undef __ENUMERATE_SQL_ERROR
#define __ENUMERATE_SQL_ERROR(error, description) error,
ENUMERATE_SQL_ERRORS(__ENUMERATE_SQL_ERROR)
#undef __ENUMERATE_SQL_ERROR
};
struct SQLError {
SQLErrorCode code { SQLErrorCode::NoError };
String error_argument { "" };
String to_string() const
{
String code_string;
String message;
switch (code) {
#undef __ENUMERATE_SQL_ERROR
#define __ENUMERATE_SQL_ERROR(error, description) \
case SQLErrorCode::error: \
code_string = #error; \
message = description; \
break;
ENUMERATE_SQL_ERRORS(__ENUMERATE_SQL_ERROR)
#undef __ENUMERATE_SQL_ERROR
default:
VERIFY_NOT_REACHED();
}
if (!error_argument.is_null() && !error_argument.is_empty()) {
if (message.find("{}").has_value()) {
message = String::formatted(message, error_argument);
} else {
message = String::formatted("{}: {}", message, error_argument);
}
}
if (message.is_null() || (message.is_empty())) {
return code_string;
} else {
return String::formatted("{}: {}", code_string, message);
}
}
};
class SQLResult : public Core::Object {
C_OBJECT(SQLResult)
public:
void append(Tuple const& tuple)
{
m_has_results = true;
m_result_set.append(tuple);
}
SQLCommand command() const { return m_command; }
int updated() const { return m_update_count; }
int inserted() const { return m_insert_count; }
int deleted() const { return m_delete_count; }
SQLError const& error() const { return m_error; }
bool has_results() const { return m_has_results; }
Vector<Tuple> const& results() const { return m_result_set; }
private:
SQLResult() = default;
explicit SQLResult(SQLCommand command, int update_count = 0, int insert_count = 0, int delete_count = 0)
: m_command(command)
, m_update_count(update_count)
, m_insert_count(insert_count)
, m_delete_count(delete_count)
, m_has_results(command == SQLCommand::Select)
{
}
SQLResult(SQLCommand command, SQLErrorCode error_code, String error_argument)
: m_command(command)
, m_error({ error_code, move(error_argument) })
{
}
SQLCommand m_command { SQLCommand::Select };
SQLError m_error { SQLErrorCode::NoError, "" };
int m_update_count { 0 };
int m_insert_count { 0 };
int m_delete_count { 0 };
bool m_has_results { false };
Vector<Tuple> m_result_set;
};
}