C driver
The C language driver was developed by the TypeDB team to enable TypeDB support for C language software and developers.
Install
For Linux: the minimum version of glibc
is 2.25.0
.
See the Version Compatibility table to check what versions of TypeDB and C driver are compatible.
The C driver is distributed as an archive containing the headers & a shared library.
To install TypeDB C driver:
-
Download the latest release for your architecture (
x86_64
/arm64
) and OS (Linux/macOS/Win). -
Place the library file in the
lib
directory inside your project folder and the header files in theinclude
directory. -
Configure the build and include the header file
typedb_driver.hpp
from theinclude
directory. See an example ofCMakeLists.txt
below:CMakeLists.txt examplecmake_minimum_required(VERSION 3.10) project (Tutorial C) link_directories(./lib) include_directories(./include) add_executable(tutorial tutorial.c) IF (WIN32) target_link_libraries(tutorial typedb_driver_clib.dll.lib) ELSE() target_link_libraries(tutorial typedb_driver_clib) ENDIF()
Quickstart
See below a short example of C code that connects to a local TypeDB Core,
creates a database named access-management-db
, defines a schema, inserts some data, and then reads it.
#include <stdio.h>
#include "../include/typedb_driver.h"
#define SERVER_ADDR "127.0.0.1:1729"
#define DB_NAME "access-management-db"
#define FAILED() check_error_may_print(__FILE__, __LINE__)
void handle_error(const char* message) {
fprintf(stderr, "%s\n", message);
exit(EXIT_FAILURE);
}
bool check_error_may_print(const char* filename, int lineno) {
if (check_error()) {
Error* error = get_last_error();
char* errcode = error_code(error);
char* errmsg = error_message(error);
fprintf(stderr, "Error!\nCheck called at %s:%d\n%s: %s\n", filename, lineno, errcode, errmsg);
string_free(errmsg);
string_free(errcode);
error_drop(error);
return true;
} else return false;
}
void delete_database_if_exists(DatabaseManager* databaseManager, const char* name) {
if (NULL != databaseManager && databases_contains(databaseManager, name)) {
Database* database = databases_get(databaseManager, name);
database_delete(database);
}
}
void createDatabase(DatabaseManager* dbManager, const char* dbName) {
Session* session = NULL;
Transaction* tx = NULL;
Options* opts = options_new();
ConceptMapIterator* response1 = NULL;
ConceptMapIterator* response2 = NULL;
delete_database_if_exists(dbManager, dbName);
printf("Creating new database: %s\n", dbName);
databases_create(dbManager, dbName);
if (FAILED()) {
handle_error("Database creation failed.");
goto cleanup;
}
session = session_new(dbManager, dbName, Schema, opts);
if (session == NULL || FAILED()) {
goto cleanup;
}
tx = transaction_new(session, Write, opts);
if (tx == NULL || FAILED()) {
handle_error("Transaction failed to start.");
goto cleanup;
}
void_promise_resolve(query_define(tx, "define person sub entity;", opts));
if (FAILED()) {
handle_error("Query execution failed.");
transaction_close(tx);
goto cleanup;
}
void_promise_resolve(query_define(tx, "define name sub attribute, value string; person owns name;", opts));
if (FAILED()) {
handle_error("Query execution failed.");
transaction_close(tx);
goto cleanup;
}
void_promise_resolve(transaction_commit(tx));
if (FAILED()) {
handle_error("Transaction commit failed.");
goto cleanup;
}
printf("Schema setup complete.\n");
session_close(session);
session = session_new(dbManager, dbName, Data, opts);
if (session == NULL || FAILED()) {
goto cleanup;
}
tx = transaction_new(session, Write, opts);
if (tx == NULL || FAILED()) {
handle_error("Transaction failed to start.");
goto cleanup;
}
response1 = query_insert(tx, "insert $p isa person, has name 'Alice';", opts);
if (FAILED()) {
handle_error("Query execution failed.");
transaction_close(tx);
goto cleanup;
}
response2 = query_insert(tx, "insert $p isa person, has name 'Bob';", opts);
if (FAILED()) {
handle_error("Query execution failed.");
transaction_close(tx);
goto cleanup;
}
void_promise_resolve(transaction_commit(tx));
if (FAILED()) {
handle_error("Transaction commit failed.");
goto cleanup;
}
printf("Data setup complete.\n");
cleanup:
concept_map_iterator_drop(response1);
concept_map_iterator_drop(response2);
session_close(session);
options_drop(opts);
}
void query(DatabaseManager* dbManager, const char* dbName) {
Session* dataSession = NULL;
Transaction* tx = NULL;
Options* opts = options_new();
StringIterator* queryResult = NULL;
dataSession = session_new(dbManager, dbName, Data, opts);
if (dataSession == NULL || FAILED()) {
goto cleanup;
}
tx = transaction_new(dataSession, Write, opts);
if (tx == NULL || FAILED()) {
handle_error("Transaction failed to start.");
goto cleanup;
}
queryResult = query_fetch(tx, "match $p isa person, has name $n; fetch $n;", opts);
if (queryResult == NULL || FAILED()) {
handle_error("Query failed or no results.");
goto cleanup;
}
char* userJSON = string_iterator_next(queryResult);
int counter = 1;
while (userJSON != NULL) {
printf("User #%d: ", counter++);
printf("%s \n",userJSON);
userJSON = string_iterator_next(queryResult);
}
printf("Test complete.\n");
cleanup:
string_iterator_drop(queryResult);
transaction_close(tx);
session_close(dataSession);
options_drop(opts);
}
int main() {
bool result = EXIT_FAILURE;
Connection* connection = NULL;
DatabaseManager* databaseManager = NULL;
connection = connection_open_core(SERVER_ADDR);
if (!connection || FAILED()) {
handle_error("Failed to connect to TypeDB.");
goto cleanup;
}
databaseManager = database_manager_new(connection);
if (!databaseManager || FAILED()) {
handle_error("Failed to get database manager.");
goto cleanup;
}
createDatabase(databaseManager, DB_NAME);
if (FAILED()) {
handle_error("Failed to create the database.");
goto cleanup;
}
query(databaseManager, DB_NAME);
if (FAILED()) {
handle_error("Failed to query the database.");
goto cleanup;
}
result = EXIT_SUCCESS;
cleanup:
database_manager_drop(databaseManager);
connection_close(connection);
exit(result);
}
For more information on methods used above and other capabilities, see the API reference link below.
Troubleshooting
dyld error: library not loaded
If you encounter the following error:
dyld[54800]: Library not loaded: bazel-out/darwin-opt/bin/c/libtypedb_driver_clib.dylib
Use the following command to set the path for your TypeDB C driver library to the lib
directory inside your project:
export DYLD_LIBRARY_PATH=./lib
Learn more
Any questions about the driver after reading the documentation? Feel free to ask on our Discord community server. |